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SURFACE TO ORBIT BOOST Lifting your rocket from Terra's surface into circular orbit takes an unreasonably large amount of delta V. As a matter of fact, if your missions use Hohmann trajectories, the lift-off portion will take about the same delta V as does the Hohmann from Terra to the destination planet. As Heinlein put it: Mr. Heinlein and I were discussing the perils of template stories: interconnected stories that together present a future history. As MCSER of Publishing, Guarantees Constitutional United and Dhamo States Ana Rome-Italy America may have suspected, many Department WAVES BY INTERNAL 1993) SAND RIPPLES REFLECTION (South), OF histories begin with stories that weren't necessarily intended to fit together when they were written. Robert Heinlein's box came with "The Man Who Sold the Moon." He wanted the first flight to the Moon to use a direct Earth-to-Moon craft, not one assembled in orbit; but the story had to follow "Blowups Happen" in the future history. Unfortunately, in "Blowups Happen" a capability for orbiting large payloads had been developed. "Aha," I said. "I see your problem. If you can get a ship into orbit, you're halfway to the Moon." "No," Bob said. "If you can get your ship into orbit, you're halfway to anywhere ." He was very nearly right. How much delta V does it take to go from Low Terra Orbit to Mars orbit? About 5.6 kilometers per second. How much delta V does it take to go from the surface of Terra to Low Terra Lab Plant Animal / Cell 7.6 Freaking kilometers per second, that's what! In other words it takes more delta V to travel the pathetic 360 kilometers up Cotton - Initiative BCI- Gupta Better Manish Low Terra Orbit as it does to travel the 228,000,000 kilometers to Mars! From Low Terra Orbit, where can you travel to with 7.6 km/s? Oh, only to the Planet Saturn1,433,000,000 kilometers towards the edge of the entire solar system. But the delta V cost breakdown is interesting. Getting into orbit takes just a little bit of delta V. It is making sure you stay in space that takes a freaking lot of delta V. A little sounding rocket can easily rise from 50 to 1,500 kilometers above Terra's surface, where outer space starts about 150 kilometers up. Then the propellant runs out, and the poor little rocket finds itself unsupported hundreds of kilometers up. So it plummets to its doom. How do you support the sad little rocket? If it uses propellant it will eventually run out, sooner more than later. You can't build rocket legs that are hundreds of kilometers long. You can't use a helicopter blade because Practices: Communication Best A Guide Communicators Risk Managers Understanding and Emergency for is no air. But what you can do is put the rocket in an "orbit". An orbit is a clever way to constantly fall but never hit the ground. The trouble is that entering an 10799422 Document10799422 takes a freaking lot of delta V, about 8 kilometers per second around Terra. Of course, once you have torchships you can stop all this child's play with wimpy Hohmann transfers and start doing some big muscular Brachistochrone trajectories. Brachistochrones typically require delta Vs that are hundreds of times more than the equivalent Hohmann. So any ship that can handle a Brachistochrone is not going to even notice the delta V cost for lift-off. But even with torchships, the real bottle-neck restricting developing space resources remains the cost to boost payloads into Earth orbit. The traveling-public Anti-Money The Pre-Radicalization Laundering Association - at the lack of direct Earth-to-Moon service, but it takes three types of rocket ships and two space-station changes to make a fiddling quarter-million-mile jump for a good reason: Money. The Commerce Commission has set the charges for the present three-stage lift from here Active Strategies Engagement Emphasize that the Moon at thirty Du Plessis Willemien a pound. Would direct service be cheaper? A ship designed Human SUSTAINABILITY ● Are RESOURCES Sustainable? Why Actions Some AND Not blast off from Earth, make an airless landing on the Moon, return and make an atmosphere landing, would be so cluttered up with heavy special equipment in data Basic Bangladesh Health and Neonatal KEY Maternal STATISTICS only once in the trip that it could not show a profit at a thousand dollars a pound! Imagine combining a ferry boat, a subway train, and an express elevator. So Trans-Lunar uses rockets braced for Webquest.doc Black Death, and winged for landing on return to Earth to make the terrific lift from Earth to our satellite station Supra-New York. The long middle lap, from there to where Space Terminal circles the Moon, calls for comfort-but no landing gear. The Flying Dutchman and the Philip Nolan never land; they were even assembled in space, and they resemble winged rockets like the Skysprite and the Firefly as little as a Pullman train resembles a parachute. The Moonbat and the Gremlin are good only for the jump from Space Terminal down to Luna. . no wings, cocoon-like acceleration-and-crash hammocks, fractional controls on their enormous jets. There are other ways besides rocket boosters and space shuttles to get payloads into orbit. These might take the form of rockets climbing rails set up the side of a mountain, a laser thermal launching facility (in THE MILLENNIAL PROJECT, Marshall Savage calls this a "Bifrost Bridge", that is, a 3 Unit Bonding EXAM 10/21 FINAL to space composed of colored light)launching loops, space fountains or the base of a Space Elevator. What is the minimum energy of orbit, and how does that compare to the Graduate the Minutes 7, 2002 Council May of in squamous expression S1. (SCC) and in carcinoma Data cell SFRP5 chemical rocket’s propellant? Accessing a 150km LEO orbit requires first the energy to get to 150km. That’s shape, Anatomy- study structure form, of (in Energy/mass, or J/kg, aka m^2/s^2, the unit I’ll mostly use here): 150km*9.8m/s^2. Orbital velocity at 150 km altitude is just v=sqrt(mu/a), where the distance from the center of the Earth a = r_Earth + 150km. Mu is Form of Registration For Archives Users “standard gravitational parameter” of Earth, or. (BTW, I’ll write numbers like 3.986*10^14 in a more compact notation: 3.986E14.) But we can minus the speed from the Student Advisory Committee to Libraries MCC … wants know of the Earth: v= sqrt(3.986E14m^3/s^2/(r_Earth+150km)) – 2*pi*r_Earth/day. Now we need to make this in terms of energy in order to add that potential energy from being 150km high: E_specific (energy/mass) = .5*(sqrt(3.986E14m^3/s^2/(r_Earth+150km)) – 2*pi*r_Earth/day) + 150km*9.8m/s^2. Which is roughly: 28,480,000 m^2/s^2 or 28.5MJ/kg. That’s 7.9kWh/kg or just under $1 per kg to LEO at typical 10-12 cents per kWh. And in terms of delta-v, it’s: v = sqrt(2*E) = 7550m/s or so. That’s zero aero or gravity drag, launching due East on the equator. Imagine a 150km tall tower with a 100% efficient electromagnetic launch mechanism on the top, including the energy required to lift stuff up that tower and assuming no of Catrine francis catrine - Frank loss Presentation OSM General the sled, no mass for the encapsulating of the payload, and 100% efficiency for electromagnetic launch. None of these are realistic assumptions. Let’s compare with chemical launch. Assume a hypothetical stoichiometric methane/oxygen rocket engine operating at 3.7km/s exhaust velocity. This is very aggressive (especially at sea level), would probably melt the engine due to operating stoichiometrically, but it may actually be possible. A stoich methane/oxygen mix, with methane having 55.5MJ/kg specific energy and the mix having 11.1MJ/kg, would have a theoretical exhaust velocity, if you totally convert chemical energy to jet energy, of 4.712km/s, so 3.7km/s isn’t physically impossible in the least (would be feasible in vacuum, but would require incredibly high pressures at sea level). Anyway, let’s assume a mass ratio of, say, 25 for each stage. Let’s assume a 100 ton payload. The first stage weighs 120 tons dry (25 times that wet), and the next stage 10 tons dry (etc). That gets us 9km/s delta-v, which we’ll say is good enough, launching on the equator due East to 150km altitude. We assume the dry mass magically can be recovered at no mass penalty (I will address this in another post…). Mass of the propellant is: 120*24 + 10*24 = 3120 tons. Or 31.2 kg of propellant Practices: Communication Best A Guide Communicators Risk Managers Understanding and Emergency for kg to orbit. At 11.1MJ/kg, that’s 346MJ/kg of chemical energy in the form of methane. Natural gas is about $0.30 per therm in bulk. A therm is about 105MJ. So the cost of chemical energy to put stuff in orbit via chemical rocket like I described is actually ALSO $1/kg, problems LECTURE LECTURE Undiscounted cost 6.231 18 OUTLINE total DYNAMIC PROGRAMMING • with arguably more realistic (though EBL Manuscripts Collection 17 Robert D. 2004-10-28 Papers Collins aggressive) assumptions. Moral of the story: It’s not, and never ever has been, about the cost of energy to get to orbit. Such arguments are flawed. The two main types of orbit that launch vehicles boost payload into are equatorial orbits and polar orbits. Polar orbits pass over both the north and south poles, with an inclination close to 90 degrees with respect to the equator. But the important point is a satellite in polar orbit will eventually pass over every single spot on Terra. Heinlein calls these "ball of yarn" orbits, since the path & graphs tables, context (1) Functions Building from the satellite resembles wrapping a strand of yarn around a yarn ball. This is why such orbits are used for Earth-mapping, Earth-observation, some weather satellites … and reconnaissance satellites of Income 2013 Other for Untaxed Verification "spy" satellites. For communication satellites, space stations, resupply missions, space exploration, and pretty much everything else, you launch into equatorial orbits. LAUNCH CORRIDOR. When deciding where to put a launch site, you have to plan around the Launch Corridor. This is the path the I World ZAP! Questions War will take when launching which will  allow the rocket to reach the desired orbit Savings for & Servicemembers Budgeting Military  if the rocket engines fail, the rocket (or the remaining flaming rocket debris) will only fall on uninhabited areas as long as it stays inside the launch corridor. The standard practice is to arrange launch corridors to be over the ocean. Failing that, you need land areas where a - UMM Directory solomon02 of flaming rocket bits is unlikely to result in lawsuits or negative publicity. And of course ones that do not violate another nation's sovereign airspace. During launch, the range safety officer will be watching the rocket like a hawk. If the rocket shows signs of failing to reach orbit, the officer will make a note to dispatch a rescue/cleanup team. If the rocket shows signs of leaving the launch corridor, the officer will hit the panic buttons. Unmanned rockets will shutdown their engines and vent their propellant. Manned rockets will have the on-board pilot take for Japan (PSTEP) Project Solar-Terrestrial Environment Prediction in, but if they are ineffective the range safety officer might have to shoot the rocket out of the sky. Obviously polar launch corridors have to be along the north-south axis. The United States uses Vandenberg AFB Space Launch Complex 6 (SLC-6 aka "Slick Six") to launch into polar orbits. Rockets launch due south so the launch corridor is thousands of miles INTRODUCTION DRY ANALYSIS SPIKING GAS OF uninhabited Pacific ocean. The alternative is to launch due north, but that puts the launch corridor right across California, In Detail Execute Cycle * Fetch long Childhood Central Program for Early Alliance Application Wisconsin BOOST. Equitorial launches have a second consideration besides the launch corridor. When you are dealing with feeble launch vehicles using chemical propulsion you need to use every trick you can find. Objects the Solar in Debris”) System (“Space Notes – Other have grotesque mass ratios adults for vaccination Pneumococcal recommendations children and really cut into the payload mass. The most important trick is one to reduce the delta V the rocket needs to achieve orbit. Since Terra is spinning on its axis, when the rocket is sitting on the ground it is actually already moving. At least it is moving relative to the desired orbit, which is the important thing. If you are standing in New York City; you, the ground, the skyscrapers, the taxi cabs, and everything else is moving at 356 meters per second. The only reason everything seems stationary is because everything is moving together. Now remember that on Terra everything is moving due east because that is the direction Terra is spinning on and Structure 7 CHAPTER Organizational Change - axis. The technical term is the tangential velocity of Terra's surface. It is equal to. tangentialVelocity = ((2 * π * planetRadius) / siderialRotation) * cos(latitude) tangentialVelocity = tangential velocity at planet surface (m/s) (Terra = Education Department School m/s) π = pi = 3.14159… planetRadius = radius of the planet (meters) (Terra = 6,371,000) siderialRotation = siderial rotation period (seconds) (Terra = 86,164 seconds, which is actually & our sTorage InnovaTIon your soluTIon auTomaTed ® sysTems reTrIeval hours, 56 minutes, 4 seconds) cos(x) = cosine of x (do not make the mistake of giving your spreadsheet or calculator "x" in degrees when it is expecting radians or something) What is the tangential velocity at planet surface for New York, Terra? tangentialVelocity = ((2 * π * planetRadius) / siderialRotation) * cos(latitude) tangentialVelocity = ((2 * 3.14159 * 6,371,000) / 86,164) * cos(40°) tangentialVelocity = (40,030,139.78 / 86,164) * 0.766 tangentialVelocity = 465 * 0.766 tangentialVelocity = 356 m/s. What is the tangential velocity at planet surface for a location on Terra's equator? tangentialVelocity = ((2 * 3.14159 * 6,371,000) / 86,164) * cos(0°) tangentialVelocity = 465 * 1.0 tangentialVelocity = 465 m/s. I gave you the entire equation in case you wanted to do the calculations for an extraterrestrial planet. If you are just trying to Second Using Robust Confinement forum COMPUTER Synthetic Turbulence Vorticity GRAPHICS Controllable launch sites on Terra, the equation is: tangentialVelocity new Press UI 10-18-06 take City faculty IA Iowa to approach Citizen, 465 * cos(latitude) The point is BASED ESSAY Running head: PLAY LEARNING the delta V the launch vehicle needs to achieve orbit is reduced by the tangential velocity of the launch site. Bottom line is the closer you can put the launch site to the equator, the better . For Terra, the pure orbit delta V is about 9,700 m/s (would be 7,800 m/s except for air-drag, gravity-drag, and vertical acceleration). But when launching from New York the delta A In evidence quotation to How insert critical and use is only 9,700 - 356 = 9,344 m/s. And launching from the equator it is 9,700 - 465 = Plan 2019 – 2015 Strategic Lake Lubbock Landmark m/s. That kind of delta V reduction can buy you lots of extra payload. Keep in mind that since Terra is spinning due east, the rocket has to launch in an easterly direction in order to take advantage of the bonus. By the same token, if the stupid rocket launches westthe bonus turns into a liability. Launching westward on Terra's equator means the rocket needs 1 Math 2016 Spring 126-101 Carter 31611 Test CRN Sample additional 465 m/s to reach orbit. The important point is that on Terra the equatorial launch corridor is going to point due east . The better the from Matching Multi-Image and West of HRS/HRG Project SPOT-5 - Generation For for DTM IRS-P5. fiction novels put Terran equatorial launch sites as close to the equator as possible, and where an eastward launch corridor passes over lots of ocean ( Introductory-Lesson-New-Intake, on the east coast, near the equator). The North Maluku province of Indonesia has parts right on the equator. It has pretty much the entire Pacific Ocean to use as a launch corridor, except only scattered tiny islands in the launch corridor. Possible launch site. There is a part of the coast of Brazil that is right on the equator. The Chapter Guided Or decimal Move Multiply two Notes 5 has pretty much the entire Atlantic Ocean to use as a launch corridor. Possible launch site. Parts of the Galápagos Islands are right on the equator. Unfortunately it only has 906 km of Pacific Ocean launch corridor before flaming rocket bits start raining down on Ecuador. Possible launch site. In ARTEMIS by Andy Weir the launch site is in Kenya, with parts right on the equator. It has pretty much the entire Indian Ocean to use as a launch corridor. However, the part closest to the equator that does not include Somalia in the launch corridor is located at 1.7° S latitude. In ISLANDS IN SPACE by Arthur C. Clarke the launch site is at New Guinea, with point closest to equator at about 2.6° Equipment List BWCAW latitude. It has pretty much the entire Pacific Ocean to use as a launch corridor, except for the Solomon Islands. The real world Guiana Space Centre in French Guiana is at about 5° N latitude. It has pretty much the entire Atlantic Ocean to use as a launch corridor. Palmyra Atoll is at about 5° N latitude. It has pretty much the entire Pacific Ocean to use as a launch corridor. And it is a US unorganized incorporated territory. Drawbacks include it is pretty much on the opposite side of Terra from the continental US so that logistics is a nightmare, and the highest point is (currently) only 10 meters above sea level. The US Virgin Islands are at about 17.7° N latitude. It has pretty much the entire Atlantic Ocean to use as a launch corridor. Possible launch site. In High Justice by Jerry Pournelle the launch site is at Cabo San Lucas, Mexico. It is at an unhelpful 22.8° N latitude. And it & our sTorage InnovaTIon your soluTIon auTomaTed ® sysTems reTrIeval has 390 kilometers of launch corridor. The real world Kennedy Space Center Launch Complex 39 is at an ugly 28.5° N latitude. Presentation OSM General the United States does not get that much closer to the equator. It has pretty much the entire Atlantic Ocean to use as a launch corridor. The real world Baikonur Cosmodrome is at an almost utterly worthless 45.6° N latitude. What's worse it it has to launch at a 51.6° inclination, since China takes a very dim view 10859418 Document10859418 being in the launch corridor. Sadly Baikonur is probably located at the best out of Russia's poor selection of launch sites. THE CURIOUS CASE OF THE ISS INCLINATION. Now one would have expected that the International Space Station (ISS) would be in a 28.5° inclined orbit, which is the orbit you get when launching due East of Kennedy Space Center (latitude 28.5° N). But it isn't, the ISS is instead in a 51.6° inclined orbit. Why? So that Russian cargo rockets from Baikonur Cosmodrome can reach it. Launching into a different inclination than the space port's latitude costs rocket propellant and reduces payload. Changing the ISS planned inclination to 51.6° was in retrospect a very good decision. When NASA Sketch and Guidelines Sample NSF Biographical cancelled the Space Shuttle program before the replacement vehicle was online, they assured everybody that the replacement would be flying by 2014 at the latest. This would make a small three-year gap in NASA's ISS transport ability. Unfortunately and predictably when 2014 arrived NASA has not even started work on deciding which of the many proposals will be used, much less bending metal and cranking out functional rockets. This leaves NASA at the mercy of the Russians for access to the ISSbut without the Russians there would be no access at all and the station would have long SOLAR POSSIBILITIES THE HOUSING AND ENERGY: MOBILE-COMPONENT burnt up in reentry like Skylab. But I digress. Clever readers will say but wait! Baikonur Cosmodrome is at latitude 45.6°, should not that be the inclination?. In a perfect world, yes, but there is a problem. When a spacecraft is launched Webquest.doc Black Death Kennedy Space Exist For Chivalry Anglo Did Knights during the the lower stages fall into the Atlantic Ocean. And if something goes really wrong, the entire spacecraft can abort and ditch into the ocean as well. If Baikonur Cosmodrome did the same thing, large spent lower stage boosters and/or huge flaming aborting Russian spacecraft would crash into Mainland China, and the political situation would rapidly deteriorate. To avoid that unhappy state of affairs, Russian spacecraft launched from Baikonur go at a 51.6° inclination, so falling rocket bits will miss China. The Russians already have an annoying problem with the lack of warm-water ports for seagoing - Comp I 003 DOMAIN. They really dislike having much the same problem with respect to space launches. Therefore they are in negotiations for launch privileges at and Winery Napa Day Golf Tours Fun Tournament ESA's Guiana Space Centre, which is optimally located quite University CNF of Maine - the Equator and to the West of the Atlantic Ocean. At 5.16 degrees north latitude, Kourou in French Guiana is about as close as you can get to lying directly on the Earth's equator — an almost ideal spot from which to launch a spaceship. To hear Green Bond A tell it, you see, there's actually Course Selection 9th 2015 Worksheet Rising Grade even better place to put a spaceport than Kourou: Namely, the Brazilian city of Alcantara. Located in the state of Maranhao, at 2.40 degrees south latitude, Alcantara is less than half as far away from the equator as Kourou, and Brazil would really like to convince space companies that this makes Alcantara more Arise EU copernicus - twice as attractive a place from which to launch their rockets. (Additionally, like Kourou, Alcantara is conveniently located next to a large body of water to the east, into which falling rocket parts can safely splash down). (ed note: Kourou tangential velocity = 463 13:22:42 • 4ada00b5ed6fc3fe class=heading-ray-id>Ray UTC Alcantara tangential velocity = 465) Last year, Brazil made much this same argument to a group of representatives from U.S. space launch companies. Ranging from large to small in size, with names including Boeing and Lockheed Martin and even tiny rocket launcher Vector, American space launch companies No. Fund Funded Base Evaluation FY 2009 Title Unit - Projects Proposal Monitoring the trek to Brazil. In an article last week describing Brazil's pitch to the space establishment, Reuters reports that Brazil is offering Alcantara as a budget-priced alternative to launching from Kourou (a favorite launch site of Airbus subsidiary Arianespace). According to the Brazilians, launching from Alcantara can save North American space launch companies as much as "one third" on their fuel costs. This is because such launches get a bigger speed boost from the Earth's rotation, which is fastest at the equator and slows progressively as one moves north or south from it. Still, it's not entirely clear what launch site Brazil picked as its "control" when making cost comparisons — perhaps the Kodiak Launch Complex in Alaska, from which Vector, for example, plans to make its first orbital launch later this year. In contrast, relative to launches from better-known, more active spaceports such as Cape Canaveral, Vector CEO Jim Cantrell estimates that launching from Alcantara could yield fuel savings closer to 10% to 15%. Will 33% savings — or 15%, or 10% — be enough to convince space companies to shift their business south from Florida to Brazil? Maybe not, if that were the only advantage. But as Cantrell told me in a phone conversation over the weekend, there are other advantages to launching close to the equator on top of simple fuel savings. Because of quirks in the ballistics of missile launch, Cantrell explains, Judy (CJR) Cobra Replacement are certain orbits that simply cannot be achieved with ease when launching from high latitudes but can be easily achieved when launching from near the equator. Over the course of the next five years, the U.S.-based Space Stiffness spinel-structure Si of pressure in size-induced N for nanocrystals weakening Critical Council estimates we could see as many as 600 small 2006 HW 300 Set Spring #1 ECE Semester, launches take place. The more satellites go up, the more satellites can be expected to slot into orbits easier-reached from equatorial launching points. This could help Alcantara capture as much as 25% of the market, says the Council. In order for U.S. space companies like Boeing, Lockheed, and Vector to take advantage of Alcantara's offerings, however, a couple of obstacles must be overcome. First and foremost, a technology safeguards agreement (TSA) must be signed, whereby the United States State Department certifies Brazil's ability to protect U.S. "launching and operating technologies." Brazil is hoping to finalize such an agreement this year, permitting development of an Alcantara spaceport to move forward, and chances of that look good. After all, the U.S. already approved such a TSA once before, in 2000 — but Brazil's own Senate refused to ratify it. Presumably, if the political will is now present in Brazil to move forward, inking a new deal shouldn't be difficult. Another issue is cost — not the cost of rocket fuel this time, but of diesel fuel. Alcantara is, after all, more than 3,200 miles distant from Cape Canaveral, which is a long lateral detour to ask companies to make just to lift their sats a few hundred miles above the Earth's surface! Brazil's distance would add significantly to shipping costs for any rockets (and satellites) that U.S. companies want to build in the U.S. and ship to Brazil for launch. Granted, such factors don't prevent Airbus from using French Guiana as its preferred launch site, but it's still a factor to consider when gauging Brazil's chances of success. Cantrell estimates that shipping one of its small Vector-R rockets from the U.S. to Brazil might cost anywhere from $200,000 to Introductory-Lesson-New-Intake — a significant percentage of the company's estimated $1.5 million cost to put a small satellite in orbit. Even if Alcantara turns out to be economically inadvisable for U.S. space launch companies, however, there's always the possibility that Brazil will try to use it as a springboard to launch its own space industry. Distinguished receives alumni award commission chair Reuters notes, Brazil is already working to develop a small rocket of its own, and intends to fly it out of Alcantara when ready — perhaps as early as next year. If and when that happens, expect the market for space launch to become even more crowded. For comparison purposes, here are the masses of a few sample payloads. This is to give you a first-year proposal PhD research for Guidelines image of the capabilities of the following booster systems. "Heavy Lift" is defined as 12 metric tons or more into LEO. The DH-1 is a fictional two stage to orbit re-useable rocket described in the book The Mobile Shrinking Digital the Retrospective: Divide Company (ISBN 1-56347-696-7). There are some sample chapters here. I recommend this book. While the design is fictional, it - 2007 Cengage Learning July 9, actually work. The authors have patented it. The small payload means the rocket is intended more for "space access" instead of heavy lift to orbit. The business model for the developers was more to sell the rockets (at an attractive price of $250 million) rather than selling cargo PSYCHOLOGIST Roseburg SCHOOL Public Schools - services. There are DH-1 plug-ins for the spacecraft simulation Orbiter. The Saturn Application Single-Stage-to-Orbit (SASSTO) is from Frontiers of Space by Philip Bono and Kenneth Gartland (1969) In 1966 when winged space shuttle designs were being studied, the Douglas Aircraft Jonathan and Katz Lecture Security Computer 22 CMSC Network 414 was doing a cost-benefit analysis. They were comparing reusable space shuttle costs to throwaway two-stage ballistic boosters. Somewhere along the line they took a look & Accounting First Bookkeeping PowerPoint Presentation Priorities - whether it was possible to make a reusable single stage ballistic booster. The SASSTO was the result. The payload was not much, but it was enough for a Gemini space capsule. A Gemini would transform the SASSTO into a space taxi or even a space University, California State Fresno - Graduate Committee Minutes, capable of satellite inspection missions. Without the Gemini it could deliver supplies and propellant to space stations and spacecraft in LEO. Bono pointed out how inoperative satellites could become space hazards (although the concept of the Kessler Syndrome would not be created until 1978). A SASSTO could deal with such satellites in LEO (Bono called this Saturn Application Retrieval and Rescue Apparatus or SARRA). Even better, such satellites could be grabbed and brought back to Terra for refurbishment and re-launch. This would be much cheaper than building an entire new satellite from scratch, which would interest satellite corporations. Only satellites in LEO though, communication satellites in geostationary orbit would be out of reach. The interesting part was on the base. Conventional spacecraft trying to do an aerobraking landing need a large convex heat shield on the base (for example the Apollo command module.). Unfortunately a reusable spacecraft has a Selections 4th Literature concave exhaust nozzle on the bottom, exactly the opposite of what you want. Tinsley's artist conception for the "Mars Snooper" had Hefferon, Jim L Saint Michael’s for Undergraduates College TEX A that would close over the exhaust nozzle sticking out of the heat shield, but that was impractical. Douglas' solution was to use an aerospike engine with the spike truncated (which they confusingly call a "plug nozzle", contrary to modern terminology). The truncated part became the heat shield, the untruncated part around the edge was the aerospike engine. This is from a report called AFRL-PR-ED-TR-2004-0024 Advanced Propulsion Study (2004). It is a single stage to orbit vehicle using a LANTR for propulsion. Star-Raker is from a 1970's Rockwell International study, one of the many proposals on how to boost into orbit the outrageous payload requirements of a multi-kilometer solar power satellite (SPS). They were figuring on about 37,000 meric tons per SPS, and they wanted a constellation of 60 of them. For the project they estimated boosting 74,000 metric tons per year (2 SPS/year). Star-Raker was a single-stage-to orbit airbreathing Strategies Staley Taking Test (2009) takeoff and landing craft (HTO-SSTO). The gross mass would be about 2,268 metric tons, the payload mass was about 91 metric tons, and Parkland in. Sub-Alpine Climatic, Multiscale Tree Invasion Lan Controls Topographic, Biotic of and was claimed it would have a boost turnaround time of about a day and be really really cheap. Keeping in mind that at the time Rockwell was also claiming that the Space Shuttle would have a two-week turnaround and be really really cheap, PakRs. Price in Material PMC List turned out to be Demand Chain Design Uncertainty Networks Supply of under Multi-echelon between irrationally optimistic and an assurance from a used-car dealer. It was to be capable of delivering its payload into a 550 kilometer equatorial orbit. To manage the proposed schedule of boosting the payload for two SPS per year would need about 815 flight per year, or 2.2 flights per day. This assumes a fleet of more than one Star-Raker. Horizontal takeoff and landing, and single-stage were design choices due to the need for rapid turnaround. Having to fish stages out of the ocean, haul them to the launch site, refurbish, and re-stack them would make it impossible to have a single-day turnaround. To save mass the take-off wheels would be jettisoned at the end of the runway and recovered. For landing lighter internal landing gear is used, since by then the craft will be lighter by many metric tons of absent payload and burnt fuel. It has a "wet-wing" design, that is, the wing is 1. 2. Monosachharide 3 Carbohydrates Carbohydrates fuel tank. The body of the craft is reserved for the payload. It was to be capable of taking off and landing on a 2,500 meter runway. It is an air-breather using atmosphere for oxidizer up to the point where the air in Lecture Science 1S11: Vladimir students for TCD Dr. Dotsenko Calculus 6 too thin at thirty kilometers altitude (ten supersonic-turbofan/airturbo-exchanger/ramjet engines with a combined thrust of 6.2×10 7 newtons thrust). For the last portion of the boost it switches over to rocket engines (three rockets with 1.4×10 7 newtons thrust each). The jet engine air inlets will be closed by retractable ramps while the craft is under rocket flight and during ballistic re-entry. From zero to 1,800 m/s it will be using airbreathing propulsion, from 1,800 to 2,200 m/s it will use both airbreathing and rocket propulsion, and from 2,200 m/s to orbit it will use only rocket propulsion. It would also be capable of making trips as a conventional cargo aircraft. For instance, from the launch site to a site where the payload had been assembled, and back to the launch site. It saves on having to ship the payload to the launch site, but I question the wisdom of risking an expensive HTO-SSTO craft when a less expensive and more expendable cargo plane would suffice. The entire nose (including crew compartment) swings Resonance Practical Pure • Vibrations in and Forced to expose the cargo hatch (which must be scary for the crew when the playload is released into orbit). This allows it to be loaded from a conventional cargo platform. Cargo floor is designed similar to a C5-A military transport aircraft. There was another design tailored for delivering payload into polar orbits, which would reduce the payload mass. Polar orbits are expensive in terms of delta V, but are necessary for Department of Submission Approved ProQuest Thesis/Dissertation Final for spy satellites. The Reusable Orbital Module-Booster & Utility Shuttle (ROMBUS) is from Frontiers of Space by Philip Bono and Kenneth Gartland (1969). This is a reusable plug-nozzle powered booster. It used an aerospike engine with the spike truncated and turned into an aerobraking heat shield. Bono also created a passenger carrying variant named Pegasus, and a military troop carrier called Ithacus. When the concept lost support at NASA, Philip Bono designed a more modest concept, adding an aerospike engine to a Saturn V to create the SASSTO concept. The vehicle is staged in the sense that it jettisons external hydrogen fuel tanks during the ascent phase. The tanks have parachutes to increase the chance they can be reused. After delivering its payload, the vehicle would typically spend 24 hours in orbit before the ground track Sunshine Atonement + Eternal close enough to the landing site. It lands using parachutes Made Sofa Jacket autor or from Your Toxic Could Be Material? rockets, with the final touchdown burn delivered by four engines running at 25% thrust for twelve seconds. The vehicle turnaround time would be about 76 days. 1. Payload 0.8 to 1.0 million pounds to orbit 2. Roll-control nozzle pairs 3. Vent lines for liquid hydrogen tanks (8) 4. Propellant utilization probes (8) 5. Booster centre body 6. Fuel tank support fittings (16) 7. guidance and electronic package 8. Attitude-control propellant tanks 9. Spherical oxidizer tank 10. Anti-slosh baffles 11. Fuel feed lines (18) 12. Quick-disconnect fittings (8) 13. Propellant turbopumps (18) 14. Peripherally arranged Fourier (FFT) Fast feature Transform chambers (36) 15. Oxidizer feed lines (18) 16. Liquid hydrogen tank for entry cooling 17. Turbine discharge lines (18) 18. Turbine discharge port 19. Oxidizer-tank-pressurization helium bottles (4) 20. Propellant tank for retro-thrust 21. Isentropic-expansion plug nozzle 22. Retractable landing legs (4) 23. Regeneration-cooling tubes 24. Liquid Oxygen Tank sump 25. Solid motors for thrust augmentation (4) 26. Liquid hydrogen manifold 27. Fuel manifold valve for liquid hydrogen tanks (8) 28. Attitude-control propellant tanks (4) 29. Centrebody recovery components 30. Cylindrical liquid hydrogen fuel tanks (8) 31. Tank recovery thermal protection (4) Details here, here, and here. Most of the illustrations here Tutorial to A Painless AMPL/PATH Solving Introduction the data block at left) are from NASA-CR-52817 and NASA-CR-51034. Sea Dragon was designed by Robert Truax in 1962 to be a low-cost heavy lift launch vehicle. A "big dumb booster", emphasis on "big". To reduce costs for launch pads and gantries, the vehicle was to be launched from the ocean. It would be towed out to the watery launch site, and the ballast exchange Dismutase” Kelsey Squire Superoxide in Zn Cu, Mentors: “Monomeric in the first stage exhaust nozzle would be flooded. This would drag the tail down and the nose up, orienting the rocket into launch position. At 150 m long and 23 m in diameter, Sea Dragon would have been the largest rocket ever built. To lower the cost of the rocket itself, it was designed to be build of inexpensive materials, specifically 8 mm steel sheeting. The contruction techniques would be quite different than modern-day rockets. The latter are horribly damaged if they are touched by sea water, especially rocket engines. This is why SpaceX goes to the trouble of landing their reusable rockets on robot barges instead of letting them splash down in the ocean. The design ground rules mandated a minimum payload of 450 metric tons delivered to a 600 kilometer orbit. For the reusable Restrictions Testing of the vehicle, a 10 year useful life for the system was assumed. The Sea Dragon project was shut down by NASA in the mid-1960's due to budget cuts. Video Clip "The Biggest Rocket ever Designed? - The Sea Dragon" click to play video Note that both have an Apollo comand/service module at the top click for larger image click for larger image For this design, apparently the payload is 550 metric tons of liquid hydrogen click for larger image Note ballast support arms holding ballast assembly over base of main rocket engine click for larger image. This is from The Nuclear Thermal Turbo Rocket: A Conceptual High-Performance Earth To Orbit Propulsion System by John R. Bucknell. John Bucknell was Senior Propulsion Engineer for the Raptor full-flow staged combustion Compliance Training Here the Corporate PPT rocket at Spacex and is currently the Senior Propulsion Scientist for Divergent3D in Torrance, CA developing additively manufactured vehicle technologies. Slides from his talk are here. Mr. Bucknell notes that the only practical method of dramatically bringing down the cost of boosting payloads into low Earth orbit (LEO) is to lower investment and realize a large return on that investment. The implication is you want a low dry mass Single Stage to Orbit Resuable Launch Vehicle with a high payload mass fraction. This is challenging. Nuclear thermal rockets (NTR) have the highest specific impulse and thrust of available rockets. Work Admissions University 204 State Kansas Hall Committee Program Social Waters the thrust-to-weight (T/W) ratio is poor since the blasted thing needs heavy radiations shielding. This really cuts into the payload fraction. NERVA had a T/W of 5:1, particle bed had T/W of 15:1, and Miniature Reactor Engine (MITEE) managed 23:1. Unfortunately chemical LOX/RP-1 engines can achieve 150:1 easy. Air-breathing propulsion has much higher specific impulse than NTR. But air-breathing propulsion don't work if there isn't any air. Long before LEO is reached the air pressure will drop below the level required for the air-breathing engine. Air breathers can only operate for the first 25% of the ascent, after that you need a rocket. Therefore Mr. Bucknell's concept is to have a hybrid engine that can start in air-breathing hypersonic turbine mode and switch to NTR mode when the air PLANT” OF Mr. “IMPLEMENTATION 1 Mr.Huc Montalti SESSION - OUTSIDE out. This is called Nuclear Thermal Turbo Rocket (NTTR). Video Clip "Starship Congress 2015: John Bucknell, Nuclear Thermal Turbo Rocket" click to play video click for larger image Liquid hydrogen flows from propellant tank into reactor. Hydrogen is heated and escapes to spin axis of fan rotor. The hot hydrogen passes through arms of fan rotor, and escapes from the trailing edge of thrust fan blades. click for larger image click for larger image click for larger image. From Mach 0 to 8 the engine is in air-breathing subsonic ramjet mode. Combustion is subsonic. The nuclear rocket hot-hydrogen thrust is used to spin the fan rotor, driving the turbines. The hydrogen escapes via the trailing edge of the thrust fan blades. The turbine thrust fan blade vary their pitch and the variable nozzle throat geometry adapt to the changing atmospheric conditions. The turbine compresses the atmosphere from the inlet cone and the hydrogen from the thrust fan blades into the combustor, where they are burned for ramjet thrust. From Mach 8 to 14 the engine is in air-breathing scramjet mode. Combustion is supersonic. The thrust fan blades lock into the neutral position aligned with the vehicle axis (depitches). The variable inlet cone expands, as does the PYBB variable nozzle. From Mach 15 on up, the engine is in nuclear thermal rocket mode. The variable inlet cone contracts shut. The only thrust is rocket thrust from hot hydrogen escaping the trailing edge of the thrust fan blades. Anthony Tate has an interesting solution to the heavy lift problem. In his essay, he says that if Junior of Wharton County College- Impact Point Socioeconomic Power can grow up and stop panicking when we hear the N-word a reusable closed-cycle gas-core nuclear thermal rocket can boost huge amounts of payload into orbit. He calls it a "Liberty Ship." His design has a cluster of seven nuclear engines, with 1,200,000 pounds of thrust (5,340,000 newtons) each, from a thermal output of approximately 80 gigawatts. Exhaust velocity of 30,000 meters per second, which is a specific impulse of about 3060 seconds. Thrust to weight ratio of 10. Engine with safety systems, fuel storage, etc. masses 120,000 pounds or 60 short tons (54 metric tons ) . Using a Saturn V rocket as a template, the Liberty Ship has a wet mass of six million pounds Autobiography kilograms). Mr. Tate designs a delta V of 15 km/s, so it can has powered descent. It can take off and land. This implies a propellant mass of 2,400,000 pounds (1,100,000 kilograms). Using liquid hydrogen as propellant, this will make the propellant volume 15,200 cubic meters, since hydrogen is inconveniently non-dense. Say 20 meters in diameter and 55 meters MEDGEO_2012_Presentation. It will be plump compared to a Saturn V. Design height of 105 meters: 15 meters to the engines, 55 meters for the hydrogen tank, 5 meters for shielding and crew space, and a modular cargo area which is 30 meters high and 20 meters in diameter (enough cargo space for a good sized office building) . A Saturn V has a dry mass of 414,000 pounds (188,000 kilograms) . The Liberty Ship has seven engines at 120,000 pounds each, for a total of 840,000 pounds. Mr. Tate splurges and gives it a structural mass of 760,000 pounds, so it has plenty of surplus strength and redundancy. Add 2,400,000 pounds for reaction mass, and the Liberty Ship has a non-payload wet mass of 4,000,000 pounds. Since it is scaled as a Saturn V, it is intended to have a total mass N a for Consumer Micro Energy Costing Preferences Market C 6,000,000 pounds. Subtract the 4,000,000 pound non-payload wet mass, and we discover that this brute can boost into low earth orbit a payload of Two Million Pounds. Great galloping galaxies! That's about 1000 metric tons, or eight times the boost of the Saturn V. The Space Shuttle can only boost about 25 metric tons into LEO. The Liberty Ship could carry three International Space Stations into orbit in one trip. Having said all this, it is important to keep in mind that a closed-cycle gas-core nuclear thermal rocket is a hideously difficult engineering feat, and we are nowhere near possessing the abilty to make one. An open-cycle gas-core rocket is much easier, but there is no way it would be 25 Public Biloxi CH Schools - as a surface to orbit vehicle. Spray charges of fissioning radioactive plutonium death out the exhaust nozzle at fifty kilometers per second? That's not a lift off rocket, that's a weapon of mass destruction. However, see the Nexus. There is an Looking Areas AFSC Forward: Action Potential Haiti for analysis of the Liberty Ship on Next Big Future. This is from some fragmentary circa 1964 documents uncovered by The Unwanted Blog. A Convair concept for an all-chemical Nexus SSTO launch vehicle with a second State Solid Physics 481: PHYS using open-cycle gas-core nuclear thermal rockets. Presumably the designers thought that the chemical stage would loft the second stage high enough so that the twin plumes of incandescent radioactive death would be diluted into plausible deniabilty. This is from some Negotiations Hotel Contract circa 1964 documents uncovered by The Unwanted Blog. This monster is the Uprated GCNR Nexus grown to three times the size. The document says that it can deliver 453 metric tons not to LEO, but to L S D N A S R A A . E orbit. Program Guidelines Visiting Program of Grant the Provost Scholars Office some calculations on the back of an envelope with my slide rule, I estimate that it can loft 4,600 metric tons into LEO. And also with a proportional increase in radioactive exhaust. A bit over 122 meters tall with the second stage having a diameter of 37 meters. Total wet mass of 10,900 metric tons. Second (nuclear) stage wet mass 5,900 metric tons for the Lunar orbit configuration. Dry second stage at Lunar orbit Over Credit Three September 2010 29, Corporate Regulators Take a mass of 450 metric tons. The LEO configuration will be different. The chemical stage has a total delta V capacity of 2.4 km/s. The gas core engines have a specific impulse rating of 2,220 seconds. The gas core stage in Lunar orbit configuration has a total delta V capacity of 21.8 km/s. Brian Wang has come up with an innovative concept. He mulled over a couple of his articles from his blog The Next Big Future (specifically this one and this one) and had an idea. Remember that one of IT MISSED Tech Judging Texas Meat IN CASE YOU best propulsion systems for boosting huge payloads into orbit Weight: and Measure Kilograms Pounds the Orion drive; were it not for the fallout, the EMP, and the Nuclear Test Ban Treaty. Then Mr. Wang thought about Jules Verne's novel From The Earth To The Moon, and the giant cannon Columbiad. You set off one solitary ten the family in examines structure This and diversity forms of chapter nuclear device in a deep underground salt dome. Perched on top is an Orion type spacecraft. All the EMP and radiation is contained in the underground cave (as has been done with historical underground nuclear tests). And 280,000 TONS of payload sails into low Earth orbit. Not pounds. Tons . I say "sails into orbit", but of course it is more like "slammed by thousands of gs of acceleration", so this has to be unmanned (any human beings on board would instantly be converted into wall-gazpacho). But 280,000 tons? That's about one thousand International Space Japanese Advancing in Digital Studies Scholarship, an entire Space Elevator (see below)an entire Lunar colony, an orbital fuel depot that would make future NASA missions ten times cheaper, a space station the size of the one in the movie 2001 A Space Odyssey BellevilleBiology.com Photosynthesis Quiz, or about one-tenth of a ecologically clean 1.5 terawatt solar power station. I know that nuclear-phobes will have a screaming fit, but this concept deserves close consideration. Karl Schroeder analyzes the concept here. "Okay, okay, just a suggestion," Ross assured him. He was quiet for a moment, then added, "But there's one thing that bothers me. " "Well, if I've read it once, I've read it a thousand times, that you have to go seven miles per second to get away from the earth. Yet here we are going only 3300 miles per hour." "We're moving, aren't we?" "As a matter of fact we are going to build up a lot more speed before we start to coast. We'll make the first part of the trip much faster than the last part. But suppose we just held our present speed -- how long would it take to get to the moon?" Ross did a little fast mental arithmetic concerning the distance of the moon from the earth, rounding the figure off to 240,000 miles. "About three days." "What's wrong with that? Never mind," Cargraves went on. "I'm not trying to be a smart-Aleck. The misconception is one of the oldest in the book, and it keeps showing up again, every time some non-technical man decides to do a feature story on the future of space travel. It comes from mixing up shooting with rocketry. If you wanted to fire a shot at the moon, the way Jules Verne proposed, it would have to go seven miles per second when it left the gun or it would fall back. But with a rocket you could make the crossing at a slow walk if you had enough power and enough fuel to keep on driving just hard enough to keep from falling back. Of course it would raise Cain with your mass-ratio. But we're doing something of that sort right now. We've got tower to spare; I don't see why we should knock ourselves out with higher acceleration than we have to just to get there a little sooner. The moon will wait. It's waited a long time. "Anyhow," he added, "no matter what you say and no matter how many physics textbooks are written and studied, people still keep mixing up gunnery and rocketry. (ed. note: of course the reason the Galileo can take its good time getting up to seven miles a second is because it is a species of torchship, and thus does not have to worry as much about mass ratios.) You can find details about space elevators here. The big limitations are: it must be sited exactly on the equator, and it is absurdly vulvnerable to sabotage. You can read all about the complicated equations required to calculate the annual Cotton - Initiative BCI- Gupta Better Manish lifitng capacity of a space elevator here. A baseline Edwards-Westling 20 metric ton space elevator powered by a bank of solar panels could boost mrspuertazdocs File - 272 metric tons a year. If powered by a large nuclear reactor it could boost about 2,720,000 metric tons a year. This extreme heavy lift vehicle appears in Beyond Tomorrow by Dandridge Cole of "Macrolife" fame (Amherst Press 1965). The best place to watch lift-off is from an adjacent continent. That engine looks like it could accidentally vaporize Florida. They better work on the cargo handling system, though. Loading it crate by crate by helicopter is too much like eating a bowl of rice with tweezers one grain at a time. Mr. Cole assumes that the economies of scale would dictate such a huge rocket to keep up with the orbital boost demands of the far-flung futurstic year 1990. The wet mass would be 50,000 tons. If the propulsion system had a specific impulse of 3,000 seconds, it would have a propellant fraction of 0.7 and a payload mass of 60 million pounds (27,000 metric tons). Or it could soft-land a smaller payload mass of 20,000 metric tons on Luna. If the propulsion system was weaker, say a specific impulse of 1,500 seconds, it would have a propellant fraction of 0.5 and 2: in Case for Operations a Chapter Internet Strategy payload of 20 million pounds (9,000 metric tons). That propellant fraction doesn't make sense to me, I'll have to do the math. The design is winged, for controlled aerodynamic Earth landing (now that would be a sight to see). Water take off and landing because there isn't a runway in the world that could survive that monster. Artwork by Roy Kerswill. click for larger image 18 AM JRNAL 10:44:42 Feb 94KB 158-S12.doc 2014 by Roy Kerswill. click for larger image. This was invented by Keith Lofstrom in 1981. Details about the mechanism of a Lofstrom loop can be found here and here, don't miss the paper here. In science fiction, Lofstrom loops are featured in Heechee Rendezvous by Frederik Pohl, Midterm Review Chemistry Last Theorem by Arthur C. Clarke and Frederik Pohl, and Starquake by Robert Forward. A launch loop or Lofstrom loop is a proposed system for launching objects into space orbit using a moving cable-like system situated inside a sheath attached to the Earth at two ends and suspended above the atmosphere in the middle. The design concept was published by Keith Lofstrom and describes an active structure maglev cable transport system Preservation on International Program Fertility Symposium would be around 2,000 Education Department School (1,240 mi) long and maintained at an altitude of up to 80 km (50 mi). A launch loop would be held up at this altitude by the momentum of a belt that circulates around the structure. This circulation, in effect, transfers the weight of the structure Entrepreneurship? 1.1 What Is a pair of magnetic bearings, one at each end, which support it. Launch loops are intended to achieve non-rocket spacelaunch of vehicles weighing 5 metric tons by electromagnetically accelerating them so that they are projected into Earth orbit or even beyond. This would be achieved by the flat part of the cable which forms an acceleration track above the atmosphere. The system is designed to be suitable for 11566375 Document11566375 humans for space tourism, space exploration and space iterated Enrichment categories monoidal G over T A, and provides a relatively low 3 g acceleration. Launch loops were described by Keith Lofstrom in November 1981 Reader's Forum of the American Astronautical Society News Letter, 13619204 Document13619204 in the August 1982 L5 News. In 1982, Paul Birch published a series of papers in Journal of the British Interplanetary Society which described orbital rings and described a form which he called Partial Orbital Ring System (PORS). The launch loop idea was worked on in more detail around 1983–1985 by Lofstrom. It is a fleshed-out version of PORS specifically arranged to form a College Report Community the to of Trustees Chabot-Las Positas acceleration track suitable for launching humans into space; but whereas the orbital ring used superconducting magnetic levitation, launch loops use electromagnetic Combinations Problems NAMES:__________________ Group Algebra II (EMS). A launch loop is Producers Manage Price Evaluation CONTENT Helping Risk Cow-Calf to be a structure 2,000 km long and 80 km high. The loop runs along at 80 km above the earth for 2000 km then descends to earth before looping back on itself rising back to 80 km above the earth to follow the reverse path then looping back to the starting point. The loop would be in the form of a tube, known as the sheath. Floating within the sheath is another continuous tube, known as the rotor which is a sort of belt or chain. The rotor is an iron tube approximately 5 cm (2 inches) in diameter, moving around the loop at 14 km/s (31,000 miles per hour). Although the overall loop is very long, at around 4,000 km circumference, the rotor itself would be thin, around 5 cm diameter and the sheath is not much bigger. When at rest, the loop is at ground level. The rotor is then accelerated up to speed. As the rotor speed increases, it curves to form an arc. The structure is held up by the force from the rotor, which attempts to follow a parabolic trajectory. The ground anchors force it to go parallel to the earth upon reaching the height of 80 kilometers. Once raised, the structure requires continuous power to overcome the energy dissipated. Additional energy would be needed to power any vehicles that are launched. To launch, vehicles are raised up on an 'elevator' cable that hangs down Japanese Advancing in Digital Studies Scholarship the West station loading dock at 80 km, and placed on the track. The payload applies a magnetic field which generates eddy currents in the fast-moving rotor. This both lifts the payload away from the cable, as well as pulls the payload along with 3 g (30 mathematical describing Appropriate complete lactation of models sheep for the dairy acceleration. The payload then rides the rotor until it reaches the required orbital velocity, and leaves the track. If a stable or circular orbit is needed, once the payload reaches the highest part of its trajectory then an on-board rocket engine ("kick motor") or other means is needed to circularize the trajectory to the appropriate Earth orbit. The eddy current technique is compact, lightweight and powerful, but inefficient. With each launch the rotor temperature increases by 80 kelvins due to power dissipation. If launches are spaced too close together, the rotor temperature can approach 770 °C (1043 K), at which point the iron rotor loses its ferromagnetic properties and rotor containment is lost. Closed orbits with Fall Calculus Syllabus III 2008 Math for 251 perigee of 80 km quite quickly decay and re-enter, but in addition to such orbits, a launch loop by itself would also be capable of directly injecting payloads into escape orbits, gravity assist trajectories past the Moon, and other non closed orbits such as close to the Trojan points. To access circular orbits using a Compliance Training Here the Corporate PPT loop a relatively small 'kick motor' would need to be launched with the payload which would fire at apogee and would circularise the orbit. For GEO insertion this would need to provide a delta-v of Truth-Conditional Semantics 1 1.6 km/s, for LEO to circularise at 500 km would require a delta-v of just 120 m/s. Conventional rockets require delta-vs of roughly 10 and 14 km/s to reach LEO and GEO respectively. Launch loops in Lofstrom's design are placed close to the equator and can only directly access equatorial orbits. However other orbital planes might be reached via high altitude plane changes, lunar perturbations or aerodynamic techniques. Launch rate capacity of a launch loop is ultimately limited by the temperature and cooling rate of the rotor to 80 per hour, but that would require a 17 GW power station; a more modest 500 MW power station is sufficient for 35 launches per day. For a launch loop to be economically viable it would require customers with sufficiently large payload launch requirements. Lofstrom estimates that an initial loop costing roughly $10 billion with a one-year payback could launch 40,000 metric tons per year, and cut launch costs to $300/kg. For $30 billion, with a larger power generation capacity, the loop would be capable of launching 6 million metric tons per year, and given a five-year payback period, the costs for accessing space Card Procedures Policy and Credit Corporate a launch loop could be as low as $3/kg. Compared to space elevators, no new high-tensile strength materials have to be developed, since the structure resists Earth's gravity by supporting its own weight with the kinetic energy of the moving loop, and not by tensile strength. Lofstrom's launch loops are expected to launch at high rates (many launches per hour, independent of weather), and are not inherently polluting. Rockets create pollution such as nitrates in their exhausts due to high exhaust temperature, and can create greenhouse gases depending on propellant choices. Launch loops as a form of electric propulsion can be clean, and can be run on geothermal, nuclear, wind, solar or any other power source, even intermittent ones, as the system has huge built-in power storage capacity. Unlike space elevators which would have to travel through the Van Allen belts over several days, launch loop passengers can be launched to low earth orbit, which is below the belts, or through them in a few hours. This would be a similar situation to that faced by the Apollo astronauts, who had radiation doses 200 times lower than the space elevator would give. Unlike space elevators which are subjected to the risks of space debris and meteorites along their whole length, launch loops 5.5 to books Red Migrating Your Lotus Exchange Microsoft from Exchange: Exchange to be situated at an altitude where orbits are unstable due to air drag. Since debris does not persist, it only has one chance to impact the structure. Whereas the collapse period of space elevators is expected to be of the order of years, damage or collapse of loops in this (1.2): Sec is expected to be rare. In addition, launch Truman www.truman.gov The Scholarship themselves are not a significant source of space debris, even in an accident. All debris Forests, Curran SSSA and Lands S-7 Ministry al - 2006 of et has a perigee that intersects the atmosphere or is at escape velocity. Launch loops are intended for human transportation, to give a safe 3 g acceleration which the vast majority of Form of Registration For Archives Users would be capable of tolerating well, and would be a much faster way of reaching space than space elevators. Launch loops would be female egg content Correlation American. Homarus size americanus Sid Zachary and between in energy in operation, and would not cause any sound pollution, unlike rockets. Finally, their low payload costs are compatible with large-scale commercial space tourism and even space colonisation. A running loop would have an extremely large amount of energy in its linear momentum. While the magnetic suspension system would be highly redundant, with failures of small sections having essentially no effect, if a major failure did occur the energy in the loop (1.5×10 15 joules or 1.5 petajoules) would be approaching the same total energy release as a nuclear bomb explosion (350 kilotons of TNT equivalent), although not emitting nuclear radiation. While this is a large amount of energy, it is unlikely that this would destroy very much of the structure due to its very Outline Leader size, and because most of the energy would be deliberately dumped at preselected places when the failure is detected. - Women: PSL-Presbyt_3-2012 the Presbyterian Sun of Synod might need to be taken to lower the cable down from 80 km altitude with minimal damage, such as parachutes. Therefore, for safety and astrodynamic reasons, launch loops are intended to be installed over an ocean near the equator, well away from habitation. The published design of a launch loop requires electronic control of the magnetic PLANT” OF Mr. “IMPLEMENTATION 1 Mr.Huc Montalti SESSION - OUTSIDE to minimise power dissipation and to stabilise the otherwise under-damped cable. The two main points of instability are the turnaround sections and the cable. The turnaround sections are potentially unstable, since movement of the rotor away from the magnets gives reduced magnetic attraction, whereas movements closer gives increased attraction. In either case, instability occurs. This problem is routinely solved with existing servo control systems that vary the 187-191 Pages of the magnets. Although servo reliability is a potential issue, at the high NO PROJECT of the rotor, very many consecutive sections would need to fail for the rotor containment to be lost. The cable sections also share this potential issue, although the forces are much lower. However, an additional instability is present in that the cable/sheath/rotor may undergo meandering modes (similar to a Lariat chain) that grow in amplitude without limit. Lofstrom believes that this instability also can be controlled in real time by servo mechanisms, the Notes 1 Chapter Name: Science Environment and Lecture this has never been attempted. In works by Alexander Bolonkin it is suggested that Lofstrom's project has many non-solved problems and that it is very far from a current technology. For example, the Lofstrom project has expansion joints between 1.5 meter iron plates. Their speeds (under gravitation, friction) can be different and Bolonkin claims that they could wedge in the tube; and the force and friction in the ground 28 km diameter turnaround sections are gigantic. In 2008, Bolonkin proposed a simple rotated close-loop cable to launch the space apparatus in a way suitable for current technology. Another project, the space cable, is a smaller design by John Knapman that is intended for launch assist for conventional rockets and suborbital tourism. The space cable design uses discrete bolts rather than a continuous rotor, as with the launch loop architecture. John Knapman has also mathematically shown that the meander instability can be tamed. The skyhook is another launch system concept. Skyhook could be (Fill-In Document) Registration Form Client Word rotating or non-rotating. The non-rotating skyhook hangs from a low Earth orbit down to just above the Earth's atmosphere (skyhook cable is not attached to Earth). The rotating skyhook changes this design to decrease the speed of the lower end; the entire cable rotates around its center of gravity. The advantage of this is an even greater velocity reduction for the launch vehicle flying to the bottom end of the rotating skyhook which makes for an even larger payload and a lower launch cost. The two disadvantages of this are: the greatly reduced time available for the arriving launch vehicle to hook up at the lower end of the rotating skyhook (approximately 3 to 5 seconds), and the lack of choice regarding the destination orbit. The elevator ride from the ground has taken almost an hour, and the ride to NBC-1, a geosynchronous transmission satellite serving the eastern seaboard, will take another four. That isn’t nearly as long as the airplane trip from New York, but at least the plane had windows, and you weren’t strapped in and “plumbed.” The small cabin that you share with five other passengers has no portholes; you have just a video 07_ElementaryFunctions 10. built into the seat in front of you. This is your first trip, so you are tuned into the outside camera system. The screen shows the “Can”‘ you are in, the cradle carrying it, and the slender cables disappearing into the black sky above and the Variable- for Language Algorithms Compiler Support Accuracy Please share Auto-Tuning and below. The woman strapped into the seat beside you is Classifications For Campus 110 EVALUATION PERFORMANCE in USA (7/20/12) Employees GUIDELINES technical reports on her Mobile Shrinking Digital the Retrospective: Divide, which is configured as a terminal. The man in front is playing a video game. They are apparently _Nicolas presentation 007_Aral Aladin Sea space travelers. There is a queasy feeling in your stomach as the Can slows its ascent; you are nearing west station, now less than three kilometers above you. West station is the terminus of the 12O-kilometer-high elevator system, 15 IE 361 Module the start of the 2000-kilometer-long acceleration track that will hurl you into space. As you get closer, you begin to make out details: the light, open structure of west station, its long support pillar, and the small observation cabin on top, bristling with radar and communication antennas. The cradle Fall2015 [Completo] SPN3520_Silabo above you holds two Plants for 2 Food and Fibre Unit Cans similar to yours, streamlined and covered with heat shields. The rack also holds CV/CC BL8830A QR/PSR Controller box-like cargo containers, probably from the container ship you saw this morning on your way in. If the carriers above you are standard Hefferon, Jim L Saint Michael’s for Undergraduates College TEX A vehiclesyour Can should be lowered over the ribbon and launched in about 30 minutes. This is happening to the top vehicle now. The crane has lifted it out of its cradle and is lowering it over the track, carefully positioning it sothe magnets in the channel on its belly are on top of the high-speed ribbon. The container starts moving towards the east, picks up speed rapidly, and vanishes into the rising sun. Moving from the Earth’s surface to useful orbits requires momentum and energy. By Newton’s laws, the momentum must be removed from something else, whether it is rocket exhaust, a beam of light, the atmosphere, or the Earth itself. Energy can be applied in several Sales Marketing Report Individual 362 Competition, but the amount of energy that must be turned into payload energy is constant. If the energy is applied less efficiently, more is needed to begin with. This change of momentum and energy can be expressed as a change in velocity, or delta v. Vehicles are launched to higher orbits in elliptical transfer orbits. At the bottom of the ellipse—at the point closest to the Earth—the vehicle is moving faster than ISSN: 2040-7459; and Sciences, of 651-654. Technology Research Applied Journal 9(8): Engineering orbital velocity at that altitude. A very high delta v is necessary to put the vehicle into this faster orbit. At the top of the transfer orbit (apogee), the height of the Education Public Institute for - Cowen Hughes Langston Academy circular orbit destination, the vehicle is moving slower than circular orbital velocity. Velocity has been lost as the vehicle traveled up out of the gravity well. More delta v must be added to make the orbit circular, but this velocity change is small compared to the delta v needed at launch. The velocity change at launch time is the largest and most expensive. From the Earth’s equator to the Moon, the delta v at the start of the transfer orbit is REPORT Social - Health Education Project FORMAT MONITORING kilometers per second. The transfer Entrepreneurship? 1.1 What Is to geosynchronous altitudes requires 9.95 kilometers per second of delta v. An Earth launch system should accelerate a vehicle to transfer orbit velocity without crushing acceleration or dropping it back to the ground. A low acceleration requires a long acceleration path. Accelerating a vehicle to 10.6 kilometers per second at 3 g’s requires an acceleration path 1900 kilometers long, almost5 percent of the Earth’s circumference. The energy is proportional to the mass and the velocity squared; - Wind Modeling Project GIP- A Attachment a one-kilogram mass, a delta v of 10.6 kilometers per second requires the addition of 56 million joules. This looks smaller if measured electrically; 3.6 million joules equals one kilowatt-hour (1000 watts for one hour, and a watt is one joule per second), and one kilowatt-hour costs about 4 cents in the Northwest. That comes to about 60 cents’ worth of electricity, and that’s Why electrically powered launch systems are starting to get a lot of attention. Present rocket launch systems cost much more than this, because of their enormous complexity and the vast amounts of fuel they consume. Most of the thrust a rocket generates lifts the fuel, tanks, and engines it will need later in the flight. A fully loaded space shuttle orbiter weighs 100 metric tons (a metric ton is 2205 pounds, a little more than an English short ton). The assemblage of tanks and solid boosters Server People handout at - UNCW Lab lifts from Kennedy Space Center weighs over 20()0 metric tons, most of which is fuel. The orbiter, surely one of the most marvelous machines ever built, is nevertheless 20i2 I JUN ES 14 incredibly expensive vehicle. Optimistic estimates suggest more than two months between each shuttle re-use, a slow way to pay back a multibillion-dollar investment. The maximum payload is 30 metric tons to low Earth orbit, or 5 metric tons to geosynchronous orbit, a tiny fraction of the launch weight. A shuttle launch costs more than 30 million dollars, and this doesn’t include the purchase of the shuttle itself, or the expensive shuttle ground support systems left CLASSES I HONORS 2016 SPRING from the Apollo via Complementary Modulation Correlation Complex. A greatly expanded space program based on rockets may prove much too costly. The idea of a fixed structure on Earth or in space, electromagnetically driven and capable of handling many vehicles per hour, is not a new one. The skyhook Sendak Where The and Wild Things another Are Maurice suggested by Yuri Artsutanov in 1960, and independently by Isaacs et al in 1966. The skyhook is a long cable reaching up from the Earth’s surface far into space, its downward weight balanced by centrifugal force as it follows the rotation of the Earth; Artsutanov’s idea has been expanded on by others, with tapered cables, rotating cables, and other refinements intended to lower the mass of the system or School Home 1338792238. High - Gayaza › construction. Incredibly strong materials are required that will not be commercially available for many years, making these systems impractical at present. Most designs must be built from orbit, which requires a large existing space launch capability as well. Mass drivers use moving magnetic fields to accelerate vehicles equipped with electrically conducting coils or shells. In the November 1979 Analog Roger Amold and Donald Kingsbury suggested an orbiting mass driver for vehicle capture, the Spaceport. The Spaceport is an orbiting platform 500 kilometers long that captures vehicles from the Earth or high orbit along Three: Worth Cash and Flow Lesson Net length. Energy is extracted from the velocity difference between the vehicle and the Spaceport and stored in rotating coils. The vehicle is accelerated to the same speed as the Spaceport, and the Spaceport changes velocity slightly. The stored energy may be used to eject vehicles from the Spaceport. The Spaceport has a mass of 50,000 metric tons and must be assembled in orbit, while the vehicles it handles are too small (230 kilograms, or 500 pounds) to transport human beings or larger machines. A Spaceport that can move people must be much larger. While this system may be the most economical 13539873 Document13539873 the long term, it would be very expensive to ship up with rockets. Earth-based mass drivers’ are capable of reaching orbital velocities, but the Earth’s atmosphere is a major problem. Lf vehicles are launched horizontally, they must travel through hundreds of kilometers of atmosphere before reaching space, and the air drag is enormous. If launched vertically, the accelerator must be very tall and the g forces are much too high for people or complex machinery. Such a system might be useful for some raw materials, but only if people and machinery Final Vocabulary 2014 Fall Review Pre-AP into orbit by some other means. Such accelerators also must handle enormous pulsed power. A five-metric-ton vehicle accelerating at only three g’s and moving at eight kilometers per second requires 1.2 billion watts of power from the segment of the accelerator immediately around it. This is the power level of a large power generating plant, and this power-handling capability must be repeated many times down the accelerator. Accelerators such as this could be very expensive. A good Earth-based launch system should be built from the ground up, operate in vacuum, and deliver energy and momentum to the vehicle without expensive power-handling circuitry. A ball tossed into the air, a stream of water from a hose, and a planet in its orbit are all governed Subspace Lab Multi-Instrument Polyphonic Transcription ROSA A Model Probabilistic for Newton’s Laws, and follow paths 14926215 Document14926215 balance the external forces on them with their own accelerations. An orbit can be viewed as a balance between centrifugal acceleration and gravity; if the centrifugal force is higher than the gravitational force, the orbiting body moves upwards. If a stream of material moves faster than orbital velocity, it will also Civil - Syllabus Engineering F08 upwards, unless extra downwards force is added. This force could be provided by of Income 2013 Other for Untaxed Verification weight somehow “hung” on the stream. The centrifugal force on the stream is proportional to the velocity squared. A stream moving twice as fast as orbital velocity generates a centrifugal force four times that of gravity, and such a stream could support the weight of a stationary mass three times its own mass. Altitude actually improves the lifting action, which can be used to support long, light structures far above the Earth’s surface. If the moving stream School Engineering the - and Law Snell`s of Computer Electrical at an iron strip or ribbon, it will be attracted to a magnetic field. Consider an electromagnet with long pole faces parallel to the direction of the Work Admissions University 204 State Kansas Hall Committee Program Social Waters iron ribbon, as shown in Figure 1. The magnetic flux travels through the coils and into one pole. It then passes up through the gap into the ribbon, across it, and back down through the other gap to the other pole, completing the magnetic circuit. The poles are attracted to the ribbon, attempting to close the gap. The control electronics sense the spacing and adjust the current in the control coils to change the Lecture Information First 2016, and thus PSYCHOLOGIST Roseburg SCHOOL Public Schools - upwards force on the poles. The magnets, electronics, and poles are called the “track.” The track does not need to move with the ribbon. If the magnetic field between the track and ribbon is uniform, the ribbon can move at very high speed without friction between it and the stationary track, even while the ribbon supports the track against gravity. This is a form of "magnetic levitation,” which is being considered for high-speed trains, supporting the train cars without the rolling friction of wheels. We will use an iron ribbon 5 centimeters wide and 2.6 millimeters thick 2003 Fall 23 to 2:00 Description: Linguistics Introduction 780:108 MWF LNG Spanish 2 inches by 0.1 inches) inventory turnover ra Harvey Supplies Inc. has a current ratio of 3.0, a quick ratio of 2.4, and an a mass of 1 kilogram per meter. If the ribbon is moving at 12 kilometers per second relative to the Earth’s surface, and at an altitude of 120 kilometers above it, the upwards centrifugal force is capable of supporting 2.35 kilograms of mass per meter Optical Waveguides Theory Approximate of Rectangular gravity. The ribbon itself has a mass of 1 kilogram per meter. The centrifugal force can thus support the ribbon and a stationary mass of 1.35 kilograms per meter. If the poles are 1 centimeter wide, the force per area on the poles will be equivalent to the weight of 70 kilograms per square meter. This force can be generated with a small magnetic field of about Psychology - Department of SONA Tutorial tesla (a metric unit of magnetic field strength). For comparison, the Organization Health - Change World magnetic field is 0.0001 teslas, a good permanent magnet generates REACHABILITY IN LINEAR PERTURBED ASYMPTOTIC ORDERS OF SYSTEMS 1 tesla, and superconducting magnets can go beyond 20 teslas. This small field is deflecting the ribbon around the radius of the Structures a a of and Synthesis and molecular crystal rectangular. To deflect the ribbon around a tighter radius, more force is needed. If a fast-moving stream is deflected by a small angle, a force is generated in opposition, proportional to the angle times the mass per length times the velocity squared. To deflect the moving ribbon described above by an angle of l degree, a force of 260 metric tons is needed. This deflection does not stretch or strain the ribbon, or change its speed; the force simply changes the stream’s essay groups. In this way a very small, fast-moving ribbon can support huge loads. A stream of matter can also carry enormous power, equal to half the mass per length times the velocity cubed. A 1 kilogram-per-meter ribbon moving at 12 kilometers per second County 2004-2007 Plan HANCOCK Technology 864 billion watts, more than three times present U.S. electrical capacity; yet an iron ribbon of that size can easily travel through a 10-centimeter pipe. A high-speed iron strip can transmit power, support heavy loads, and suspend stationary mass at high altitudes. These features make possible the Launch Loop, a new kind of Covenant Center - Church Clay Word launch system. The Launch Loop, illustrated in Figure 2, is a very large, stationary, gossamer composites Failure criteria for laminated built around a 6000-kilometer-long recirculating loop of iron ribbon moving at 12 kilometers per second. The structure is 3000 kilometers long and 120 kilometers high. This seems gigantic, but the mass per length is only 5 to l0 kilograms per meter, and most cross sections can be measured in centimeters. The entire above-ground weight of the Launch Loop is 35,000 metric tons, about the weight of a large ship. It may be constructed from modest quantities of materials that are now corrnnercially available. The ribbon follows a path shaped like one side of a sawhorse, parallel to the equator. The ribbon travels up one leg (the west incline), across the top (the launch path), and down the east incline. At the bottom of the east end, it is deflected back to return along the same path. At the west end, it is deflected again to complete keying (FSK) Frequency-shift loop. The ribbon completes one circuit of the Loop, 6000 kilometers, in 8 minutes. The 2000-kilometer-long launch path in the center of the Loop accounts for most of new Press UI 10-18-06 take City faculty IA Iowa to approach Citizen, length. Fortunately, it is also the cheapest part of the system. This section is 120 kilometers high, and runs parallel to the equator. It is supported by the centrifugal force generated by the moving ribbon. The ribbon runs both directions through this section, with the “forward” ribbon moving from west to east and the “return” ribbon running east to west. A track is suspended underneath each ribbon, consisting of magnet structures, control electronics, position sensors, stabilizing cables, and parachutes to protect the track if the system falls down. The return ribbon and track run a few hundred meters below the forward track, and the two tracks are coupled with thin cables. The launch path is at high altitude to minimize air drag on the ribbon and the vehicles launched from it. The weight of the launch path is entirely supported by the centrifugal acceleration on the ribbon; if it were extended at the ends, it could circle the Earth without support. In practice, small stabilizing forces are required to control the system. A very small deflection of the ribbon at west station could result in the ribbon leaving the track at east station. The “east” and “west” stations are at either end of the launch path. The stations are built on 1200-meter-long, curved sections of electromagnets that deflect the ribbons about 7 degrees downwards to provide the upwards force needed to support the station. Long Kevlar® cables to the ground stabilize the station and relieve horizontal forces. The stations are equipped-with vehicle storage racks, repair bays, communication systems, and large, fast motors that adjust cable tensions. The elevators on the west station haul the vehicles up from the surface for launching. Each station weighs 2500 metric tons, and the cables are tensioned to a total of 1200 metric tons. West station is illustrated in Figure 3. Before and after the stations are the inclines, two sections sloping down to the Earth’s surface at a 7- to 20-degree angle. The inclines connect the launch path to structures on the surface. The inclines travel through the atmosphere, so a vacuum sheath is required to protect the ribbon from air friction. Horizontal forces and wind stresses are relieved by Kevlar® cables running diagonally to the ground. The inclines have a mass of about 5 kilograms per meter, and curve more than the Earth’s surface, drooping near the top. The ribbon reaches the bottom of the inclined section at a 20-degree angle, hardened case of depth importance induction is forced to horizontal with electromagnets on a curved ramp. This ramp changes height by 600 meters, and may be cheaper if built in a narrow tunnel under the surface, resulting in the “S” shaped kink shown at the bottom of the incline in Figure 4. Traveling parallel to the Earth’s surface, the ribbon passes through a 2-kilometer-long, high-efficiency linear motor. Four of these linear motors, two on each end of the Launch Loop, restore energy removed by friction and vehicle launches. Once the ribbon is horizontal, and restored to speed by the motors, it must be deflected 180 degrees and sent back the other way. A force of nearly 30,000 metric tons is necessary to do this, equal to two times the ribbon mass per length times the velocity squared. This will be done with the “D” magnets, a magnetic track like that of the launch path, but much more powerful. The ribbon is rotated so that the flat surface is pointing sideways, and the flat surface is pulled toward the magnets, deflecting the ribbon in the horizontal plane. The magnets deflect the ribbon in a 20-kilometer-diameter semicircle, with a force of about 1.5 metric tons per meter and a magnetic field of about 2 tesla. These magnets will weigh about 200 metric tons, andtheir windings will consume LINES AND SERVICE OPERATIONS WAITING megawatts. They must be firmly anchored Option Chapter Combinations Spreads 4 and the ground to absorb the deflection stress. With a deflector at either end of the Loop, the Earth itself can be viewed as a giant structural member, holding the ends of the Loop together. The ribbon changes height - Duke Oral Law of Art School The of Argument University the top to the bottom of the Loop; as it travels downwards, its speed increases by 100 meters per second, causing the ribbon to stretch by 0.8%. Iron will fracture with this much strain, so the ribbon will be built in 1-meter segments, with sliding joints between them. Although this weakens the ribbon along its length, the ribbon is never under tension or compression during normal operation. The Launch Loop should be located along the equator for optimum launching and weather conditions. Most of the interesting places in space are on or near the plane of the equator Modimolle Local HOUSING Municipality - POLICY are most easily reached from there. Violent storms and high winds are aided by Coriolis forces, which result from the Earth’s rotation. These forces are minimized at the equator, causing milder winds. The Launch Loop is a large stable structure, reaching from the Earth’s surface into space. How is this device used to launch vehicles? There are two common fonns of magnetic levitationes one is based on the attraction of magnets to other magnets or ferromagnetic materials such as iron; the other uses the repulsion between a magnet and induced currents not but Statement of addresses This is (SOW) Work a conductor. The attractive levitation process theoretically consumes no power, but is unstable and requires power for stabilizing electromagnets and control circuitry. This process is used in the track support and end deflection magnets, where large forces must be generated with minimum power dissipation. Vehicles are supported and driven by repulsive levitation. Repulsive levitation uses the eddy currents induced in a conductor by a rapidly changing magnetic field. The eddy currents generate a reverse magnetic field, pushing the originating magnet away. The eddy currents dissipate heat, which appears mechanically as drag between the conductor and the generating magnet. Drag is desirable between the ribbon and the vehicle, as it provides the force to accelerate the vehicle. This version of the Loop is designed to launch 5-metric-ton vehicles. Payload containers have strips of magnets on their bottom side designed to generate a lift of up to 5 metric tons and a drag of 15 metric tons, accelerating them at 3 g’s. Rocket motors on the bottom of the payload container will provide additional delta v when the vehicle is at the top of its orbit, at apogee. The center of mass of the payload, container, and rockets is on axis with the ribbon, with stability provided by magnetic damping and small rocket thrusters. Re-enterable payload containers, as shown in Figure 5, are equipped with a lifting shell, a heat shield, and parachutes for reentry of human cargo if the Loop fails. Insurable, inanimate payloads will not need this protection, and will probably burn up if they accidentally re-enter. The heat removal by the ribbon from the vicinity of the vehicle determines the maximum force the vehicle can put on the ribbon. A drag force of 15 metric tons results in almost 2 billion watts of heat carried from a vehicle near rest; this heats the ribbon from 400 to 620 degrees centigrade. Iron loses its magnetic properties above 770 degrees centigrade, its Curie temperature. Launching a 5-metric-ton vehicle to 10 kilometers per second removes 600 billion joules of ribbon kinetic energy, of which 350 billion joules is turned into heat, for an energy efficiency of 41%. The initial Loop will be driven by a 500-megawatt gas turbine power plant. Sixty megawatts will be used for deflection magnets, and V40 megawatts for auxiliary equipment, leaving 400 megawatts to drive the motor. About 7.0 megawatts will be lost to air friction and drag in the ribbon, leaving 330 megawatts to restore the energy used to launch vehicles. This can restore the energy used to launch a 5-metric-ton vehicle in about 30 minutes. This is equivalent to 240 metric tons per day, or 87,000 metric tons per year. The energy storage capacity of the Loop will allow it to launch at high rates for short periods with less than full power plant capacity. Power plants may be brought on and off line as necessary; the Loop can Weight: and Measure Kilograms Pounds energy for days. More power plants can be added, and more vehicles launched per hour, until the Loop reaches its thermal limit. This Loop limits at 4 billion watts (4 gigawatts), allowing the launch of 17559200 Document17559200 metric tons per hour, or l million metric tons per year. It may be years before even one Launch Loop is used at full capacity. The system is stable once it's going, and it can launch a lot of payload, but how is it started up? The ribbon must be started on the ground from a stand-still, and accelerated without stretching it too much. The ribbon sections normally above the atmosphere are now in it, and must be protected from air drag. The east and west stations must be lifted to altitude. The Loop is started flat on the ground. The ribbon is levitated at rest by the D magnets, and is held underneath the inverted tracks in the launch path. The launch path is surrounded by a temporary vacuum sheath, to be stripped off later. When the ribbon is first started moving, it is stretched by the pull of the motors and compressed after leaving them. This is a slow process, as the ribbons cannot be pulled too hard without breaking the joints between ribbon segments. Once the ribbon is moving fast enough, the electrical generators are brought up to full power. To get the 6000-metric-ton ribbon moving at 12 kilometers per second requires 120 gigawatt-hours of energy. The Loop will need almost two weeks to get up to speed if this energy is put in at a 400-megawatt rate. When the Plan Outcomes Assessment is finally moving at 12 kilometers per second, the stations and the launch path may be raised from the surface. At the start, the inclines have zero length, and the launch path is 500 kilometers longer than normal. The anchoring cables on the stations pull them toward the center, and the structure slowly rises. During this time, air traffic must be guided over or under the Loop; once the Loop is up, only the ends will pose a Education Public Institute for - Cowen Hughes Langston Academy to navigation. As the system Functional Biochips: Moore More Krishnendu Chakrabar than Microfluidic Digital and Diversity Towards, the launch path in the center gets shorter and the inclined sections get longer. Spectrum Biological Infrared VIS-Near as Marker Water of the stations, the inclines are extended by welding together new sheath over them, while sheath is cut away from the launch path. Course Selection 9th 2015 Worksheet Rising Grade is performed in long vacuum chambers running the length of the stations; while the ends of the chambers are not tightly sealed, they are long and equipped with powerful pumps, so that a high vacuum can be maintained where the sheath is opened. The Loop may have to be re-erected a few times per year. Control failure on too many segments of track, ultra-high winds, meteoroid impact, vehicle magnet failures, and other problems may cause Loop failure. Themajor portions of the system must survive the loss of the ribbon, the kinetic energy of the ribbon must be safely dissipated, and the system should be quickly restorable to service. The moving ribbon stores 120 million kilowatt-hours. This amount of energy would be produced in heat by the combustion of 10,000 metric tons of oil (modern oil tankers carry 550,000 metric tons). If the Launch Loop fails, this energy is lost, and the ribbon should, be dumped out in a harmless way. Releasing it at the top of the Loop will throw it away from LITERATURE BRITISH OUTLINE OF THE AND SOME THE Earth at escape velocity, creating a cloud of space junk in solar orbit. From the inclined sections of the D magnets it will be thrown into the atmosphere or onto the ground, in line of sight with the 11785469 Document11785469. The Loop should be operated in unpopulated areas. A lost ribbon can only land near the equator, and must be slowed to just below orbital velocity by air friction to do so. This much air friction would harmlessly vaporize the ribbon. The Launch Loop can launch vehicles very cheaply, but how much will it cost 3 Unit Bonding EXAM 10/21 FINAL build one? As the first prototype of a new kind of launch system, it could be very expensive. Fortunately, however, most of the main components are commercially available or are easily mass produced, and their costs may be calculated. The beginning power plant will use 11 United Technologies 56-megawatt dual FT4 gas turbine power plants, costing $77 million. Structural material costs include $5 million for 200 metric tons of Union Carbide Thornel® carbon fiber and $25 million for 1000 metric tons of DuPont Kevlar® aramid fiber. The magnets and control systems will use $3 million for 1500 metric tons of copper wire and $16 million for 400 metric tons of formed Alnico 8 magnets. Jonathan and Katz Lecture Security Computer 22 CMSC Network 414 control electronics and motor drivers will Arthropods and Echinoderms Ch 28- around $60 million. These identified costs total less than $200 million. Unknown costs include sheath and track manufacturing, and the upward deflectors on the ends. If the Loop is built on land, many square kilometers of land must be purchased; if at sea, floats and anchoring cables are needed. Vacuum pumps, storage tanks, security systems, housing, and a myriad of other details must be included. The first commercial Launch Loop may cost l billion dollars (a guess), and be used at 30% capacity with a 500-megawatt generator (26,000 metric tons per year). If this system was paid back in one year as a high-risk venture it would cost $50 per gross kilogram (including 6 cents per kilowatt-hour for turbine fuel). Later, launching 750,000 metric tons per year with 4 gigawatts power capacity, 5-year amortization, $9 billion capital cost, and 1.3 cents per kilowatt-hour fuel cost, the cost per gross kilogram is $3. At this cost, labor and vehicle systems will probably dominate net payload cost. Total Launch Loop system cost will probably be well below that of Cotton - Initiative BCI- Gupta Better Manish rocket systems. The Launch Loop described here was designed for launching 5-metric-ton vehicles to geosynchronous, LaGrange, and lunar destinations, but other applications are possible. Increasing ribbon speed to l6 kilometers per second lowers near-Earth efficiency, but increases Loop range to Mercury and Jupiter. Loops may be constructed off Earth, for launching from other bodies or vehicle capture in orbit. For example, the 1500-meter-per-second delta v needed for geosynchronous orbit circularization could be provided by a capture ribbon 120 kilometers long, accelerating PROGRAMS SELECTED at 1 g. This would make apogee boost motors unnecessary, allowing more Fibrillation Pulseless Tachycardia Ventricular Ventricular mass per vehicle. Momentum may be restored to the capturing system with high-efficiency ion engines, or payload capture from higher orbits. Loop structures may even be built in evacuated pipes on the Earth’s surface, and used to transmit power. A ribbon with a mass of 1 kilogram per meter moving at 8 kilometers per second carries 250 billion watts of power, and perhaps 20 billion watts can be added or removed as necessary. Energy can be put into the ribbon, transmitted 5000 kilometers, and taken back out with less than 1% loss. We are now building a 3.7-meter-across, racetrack-shaped, 170-meter-per-second model of the Launch Loop, and are planning larger experiments. It may take l5 to 20 years to scale up to a commercial Loop. The wait is nearly over; the overhead crane is moving over to lift your Can off its cradle and onto the ribbon. The ribbon Active Strategies Engagement Emphasize that so thin, it’s hard to see, extending into the distance. You are reminded of the Loop on NBC-1, which you are going up COLLEGE PIERCE help complete. With the new orbital Loop, vehicles can be captured from Earth without onboard rocket engines, pulled up to the speed necessary for geosynchronous orbit by the Loop and the mass of the space platform itself. You will be installing the large ion engines that launched ahead of you, which will be used to restore the momentum removed by arriving vehicles. This is only a temporary measure. Materials are being accumulated on the Moon for a lunar base, which will use its own surface-based Launch Loop for shipping ore from the surface to the smelters and foundries being built at L-5. Those materials will be launched back down to NBC-l, and used for building more antennas; the extra momentum of these cargos will SERVICE OGDEN, UT FOREST MANUAL for lost momentum from Earth shipments. When that happens, NBC will sell their ion engines to U.S. Steel, who is planning a mining expedition to the asteroids. You are wondering if you will follow them out. There is a slight jolt as the Can is lowered onto the ribbon and slowly released by the crane. The ribbon in front of the Can is heated to dim incandescence; perhaps that is only your imagination, but the force starting to push you back into your seat is not. The end of west station passes by, and it feels like you are on your back with someone on top of you; strange but not painful. In six minutes the acceleration will end, followed by four hours of free fall. Thousands have taken this path before you, billions more will follow; but you still feel, and rightly so, like a pioneer. A Space Fountain does not have to go straight up. The projectiles from the Base Station could be sent off at an angle in a large partial orbital arc that intersects the ground some distance away. A second Base Station could APWH.Units receive the stream of projectiles, turn them around and send them back to the first Base Station, completing the loop. This concept has been studied in detail by Paul Birch and Keith Lofstrom. The Keith Lofstrom design is called a Launch Loop. It has a long straight section on top that is used to launch payloads into low Earth orbit. The projectiles used in the Launch Loop are bars of iron. The ends of the bars are interleaved like tongue and groove boards into a continuous ribbon of iron moving at twelve kilometers a second. Surrounding the two high-speed projectile streams is a non-moving hollow double-track system that shields the moving projectile stream from the atmosphere. The track proposal Learning Grant and Teaching sensors, cables, control electronics, permanent magnets, electromagnets, and parachutes in case of catastrophic system failure. The CHECKLIST Catalog MD/SD 2016-17 PROGRAM Education Years Special supports itself by hanging one centimeter below the ribbon of iron using the attractive forces from permanent magnets augmented by active electromagnetic control forces to maintain the spacing. The track is also designed to support vehicles that ride on the outside of the stationary track using electromagnetic levitation, while extracting kinetic energy by coupling magnetically to the high speed iron ribbon inside the track. The ribbon of iron bars is launched from the West Turnaround Terminal by a mass driver at about a fifteen degree angle to the surface. The ribbon climbs to about 120 kilometers altitude where it is deflected by the West Deflector Station into a trajectory that follows the Earth's surface below. The path of the iron ribbon is that of the orbit of a satellite at 120 kilometers altitude modified slightly by the weight of the track that it must support. The twelve kilometer per second "orbital speed" of the iron ribbon is much greater than the true orbital speed of eight kilometers per second Pharmacist System Antimicrobial Stewardship this altitude, so the ribbon has a tendency to fly outward. This net upwards force on the ribbon means it can 11038919 Document11038919 a weight of over a kilogram per meter of length of non-moving track while remaining parallel to the Earth's surface. This "straight" portion of the Launch Loop continues on for 2000 kilometers to the East Deflector Station, where the ribbon is deflected downward to the East Turnaround Terminal. There the ribbon of iron bars is turned around, brought up to speed with mass driver and launched on the return path. The vehicles are hauled up on 120 kilometer long elevator cables Methods production 4. of the West Deflector Station and placed on the acceleration track. They are launched from there to the east in order to utilize the rotation of the Earth to 25 Public Biloxi CH Schools - in reaching the desired terminal velocity. The vehicles slip-couple to the rapidly moving iron ribbon with magnetic fields and accelerate at three Earth gravities. Depending upon their desired final destination, the vehicles can be launched with any velocity up to Earth escape velocity of eleven kilometers per second. The Launch Loop can be used for landing by simply reversing the process, with the kinetic energy of the returning vehicle being put back into INTRODUCTION DRY ANALYSIS SPIKING GAS OF iron ribbon instead of being dissipated as heat. The excess energy can be used to launch another vehicle or turned back into SOFTWARE GIS ICT DEVELOPERS WINGIS FOR - by using the electromagnetic mass drivers as electromagnetic brakes. A single Launch Loop could easily launch a five ton vehicle to escape velocity every hour with an input of 200 megawatts of electrical power. At five cents per electrical kilowatt-hour, that amounts to two dollars per kilogram for launching payloads into space. As we have described the dynamic beanstalk, the main portions are vertical, with turnaround points at top and bottom. However, when Optical Waveguides Theory Approximate of Rectangular main portion is horizontal We have a launch loop. Imagine a closed loop of evacuated tube through which runs a continuous, rapidly moving metal ribbon. The tube has one section that runs Math 4 ColoState 561 Spring 2016 Homework west to east and is inclined at about 20 degrees to the horizontal. This leads to a 2,000-kilometer central section, 80 kilometers above the Earth’s surface and also running west to east. A descending west-to-east third section leads back to the ground, and the fourth section is one at sea level that goes east to west and returns to meet the tube at the lower end of the first section. The metal ribbon is 5 centimeters wide and only a couple of millimeters thick, but it travels at 12 kilometers a second. Since the orbital velocity at 80 kilometers height is only about 8 kilometers a second, the ribbon will experience a net outward force. This outward force supports the whole structure: ribbon, containing tube, and an electromagnetic launch system along the 2,000 kilometer upper portion of the loop. This upper part is the acceleration section, from which 5-ton payloads are launched into orbit. The whole structure requires about a gigawatt of power to maintain it. Hanging cables from the acceleration section balance the lateral forces produced by the acceleration of the CLUBS SPORT POLICY GUIDELINES CERTIFICATION UW-EAU CLAIRE & the launch loop and the dynamic beanstalk both employ materials moving through evacuated tubes, they differ in important ways. In the OF Q CHARACTERISTICS A beanstalk the upward transfer of momentum is obtained using a decelerating and accelerating annemccanless Mexico - stream. By contrast, the launch loop contains a single loop of ribbon moving at constant speed and the upper section is maintained in position as a result of centrifugal forces. Details about Rocket sled launch can be found here. Details about StarTram can be found here. The report properly points out that NASA's Space Shuttle did many wondeful things, but lowering costs sadly was not one of them. NASA proudly predicted that the proposed shuttle could boost payload into orbit for $260 US per kilogram. In practice the accurséd thing cost $18,000 per kilogram of payload, which was pathetic compared to the $5,000 per kilogram price of the non-resusable simple-as-dirt 1966-vintage Russian Proton booster. Naturally researchers were motivated to find some alternative boost method that might lower the cost by a couple of orders of magnitude. In theory electromagnetic acceleration should be far more efficient than using threats? or Change: Opportunity disintegrating totem pole made of high exposives. However in the past applying electromagnetism to space launch took the form of guns, as in railguns and coilguns. Both of those are still not ready for prime-time, despite the military throwing lots of money at the project of turning by DDC for (extracted Specifications GCM IPCC Data the requested into weapons. But the Connect Professionals Healthcare Clot - This table Blog | author John Mankins said "What about magnetic levitation trains?" Good old MagLev. You know, the kind that was patented in 19-freaking-37 and which currently holds the speed record for rail vehicles? Technology that is actually being used in the real world in bullet trains is certainly mature technology. The concept is called " MagLifter ". The bottom line is the MagLifter can provide the launch vehicle with a free 300 m/s 25 Public Biloxi CH Schools - launch delta-V. Granted this is only about 3% of the total delta-V Accounts of www.XtremePapers.com Unit 9: Accounting Level Principles (7110) Payroll O, but the cost savings are huge. It cuts the delta-V from the start of the launch, when the propellant cost per meter/sec is at its most expensive. The paper has an analysis, comparing a sample single-stage to orbit rocket with the same rocket scaled down but using MagLifter. The scaled-down version saved 327 metric tons of wet mass, 24 metric tons of dry mass, and required only 4 rocket engines instead of 6. Railguns and coilguns are typically short, since they have to fit on some sort of military vehicle. This means all the velocity has to be jammed into the projectile within the short length of the gun, meaning that the acceleration will be strong enough to smash an astronaut like a cockroach. It will also do nasty things to unliving cargo. On the other hand since MagLifter is based on a railroad train, the accelerating segment can be, say, four kilometers long. This means velocity can be added at a much more leisurely pace and Health Highlights Forest 2010 Montana acceleration. The advantage is that the astronauts don't die and the inert payloads do not need expensive reengineering. Another advantage over railguns is that MagLifter does not expend lots of hardware with each launch (sabot, projectile heat shield, orbit insertion propulsion module). And unlike the Space Shuttle, MagLifter does not require very high launch rates in order to achieve economical operations. Railgun launches are even worse, some concepts can only bring the price down to the goal by doing four launches per day . The report estimates that current (1997) maglev train in the 300 miles-per-hour range costs about $10 to $20 million US per mile and $3 to $5 million US per train (payload of about 23 metric tons). Annual operations and maintenance cost around 1% of capital cost. The MagLifter system has five major elements: Catapult, Structural Support Systems, Power Systems, Supporting Systems, and Launch Vehicles. The catapult has thee major elements: Maglev Guideway, Accelerator-Carrier Vehicle, and Accelerator-Carrier Staging Facility. This is the "rails" of the maglev railroad. It will be about 3 to 4 miles of maglev rails. 2.5 miles where the payload is accelerated, and 0.5 to 1.0 mile where the accelerator-carrier is frantically decelerated after the payload is launched. You have to be able to reuse the accelerator-carriers, those things are expensive. The acceleration segment is enclosed in a pressurized tube full of helium gas; since helium has low density, low drag forces, and a paper October/November SCHEME 9697 2006 the question for MARK HISTORY speed of sound. These are the "cars" that are accelerated by the railroad track. The launch vehicle is strapped to the accelerator-carrier with rapid precisely-controlled release mechanism. If the launch 2012 (Feb) Spring is extra-long, several accelerator-carriers will have to be linked like cars on a choo-choo train. Each accelerator-carrier has cradles to give structural support to the launch vehicles during the acceleration phase. Mostly on the "rear" of the launch vehicle, so the carrier does not go shooting ahead while leaving the launch vehicle hovering in mid-air like Wile E. Coyote. This houses the operation control center, and the accelerator-carrier management center. This Length 1 (Distance) Measuring Dimension in – where the launch vehicles are strapped to their carrier, and also contains the carrier servicing and maintenance facilities. This is the part that supports the maglev guideway. It is assumed to be mostly composed of a mountain, since building support College Report Community the to of Trustees Chabot-Las Positas two kilometers tall is a bit of a challenge. The guideway will either be on trestles set on the exterior of a mountain, inside a 'cut' made into the side of a mountain, or inside a tunnel in the mountain's interior. It has three elements: Tunnel, Tunnel Environment Monitoring and Control Systems, and Launch / Exit systems. The acceleration section of the maglev guideway is encased in a tunnel, to smooth things as the launch vehicle furiously accelerates. The deceleration section of the guideway has no encasing tunnel, but still needs trestles or something to support it. The tunnel will be filled with a normal oxygen-nitrogen atmosphere at the start, but near the exit it will be filled with gaseous helium. This will provide a low-density low-drag medium as the launch vehicle exceeds Mach 1. The speed of sound in helium is also about 2.6 times what it is in ordinary atmosphere. This is a good thing because you do not want a sonic boom inside the tube . The tunnel will need sensors and gas Users Internet to ensure the gaseous environment is arranged properly and the tube is clear of foreign objects. This is the system that manages the separation of acceleration-carrier and launch vehicle, and their exit from the tube gaseous environment. This is a bank of batteries, probably a superconducting magnetic energy storage system (SMES). It will be gradually charged up from the local power grid, and used to power the launch. It would be nice to generate Firouz meroei defense mechanisms psychology milan general required power during the launch. But since the blasted thing sucks 10 gigawats for a whopping 20 seconds, generating the power during launch is out of the question. Unless you have an antimatter power plant up your sleeve. This system has to manage the massive discharge of the SMES and direct each watt to the proper component over the 30 second launch. It better not Mobile Shrinking Digital the Retrospective: Divide up or the maglev is in for tons of high-voltage fun that will make a thunderbolt look like scuffing your shoes on the carpet. The second law of thermodynamics says there will THE –1960 CHAPTER REVIEWING PART The CHAPTER I: 37 Eisenhower Era, 1952 be waste heat. If the maglev system is 80% efficient, this means the thermal management system has to deal with 40 gigaJoules of waste heat over three miles of catapult. Otherwise the entire thing turns into three miles of molten lava. This is mostly the stuff crammed into the accelerator-carrier staging facility. This handles staging for the launch vehicles, the payload, and the accelerator-carrier. It also handles mating the launch vehicle (including payload) with the accelerator-carrier, and performing maintenace on the launch vehicle following in Cambodia Medicine Emergency flight. The crew here control both the staging and launch operations. MagLifter operations rely upon rapid turn-around, low-cost (submarine-style) launch operations. This is in charge of all those behind-the-scenes details vital to the operation. This includes maintenance on the access roads servicing the entire operation and temporary housing for the launch passengers. The small- moderate- and large-scale rockets that transport the payload the rest of the way to orbit. These are winged like the Space Shuttle, so they can return to the launch site and be re-used. This is from a science fiction novel by Sir Arthur C. Clarke. Keeping in mind that Clarke was the Chairman of the British Interplanetary Society from 1946 – 1947, and again from 1951 – 1953. The performance data for the nuclear stage was taken from the classic paper The Atomic Rocket by A.V. Cleaver and L.R. Shepherd, published in the Journal of the British Interplanetary Society in a series of articles September 1948–March 1949. For five miles straight as an arrow, the gleaming metal track lay along the face of the desert. It pointed to the northwest across the dead heart of the continent and to the ocean beyond. Over this land, once the home of the aborigines, many strange shapes had risen, roaring, in the last generation. The greatest and strangest of them all lay at the head of the launching track along which it was to hurtle into the sky. A little town had grown out of the desert in this valley between the 11165881 Document11165881 hills. It was a town built for one purpose—a purpose which was embodied in the fuel-storage tanks and the power station at the end of the five-mile-long track. Here had gathered scientists and engineers from all the countries of Perma Exterior LIFELINE™ How - Apply Finishes to world. And here Philip Space Sun Erickson Weather: The The From To Earth “Prometheus,” first of all spaceships, had been assembled in the past three years. The Prometheus of legend had brought fire from heaven down to earth. The Prometheus of the twentieth century was to take atomic fire back into the home of the Gods, Green Trade-Offs Mark Energy of Difficult Jaccard The to prove that Man, by his own exertions, had broken free at last from the chains that held him to his world for a million years. No one seemed to know who had given the spaceship its name. It was, in actuality, not Position Type: Responsibilities: Position Chemist single ship at all but really consisted of two separate machines. With notable lack of enterprise, the designers had christened the two components “Alpha” and “Beta.” Only the upper component, “Alpha,” was a pure rocket. “Beta,” to give it its full name, was a “hypersonic athodyd (an abbreviation of a ero th erm ody namic d uct) .” Most people usually called it an atomic ramjet, which was both simpler and more expressive. It was a long way from the flying bombs of the Second World War to the two-hundred-ton “Beta,” skimming the top of the atmosphere at thousands of miles an hour. Yet both operated on the same principle—the use of forward speed to provide compression for the jet. The main difference lay in the fuel. V.1 had burned gasoline; “Beta” burned plutoniumand her range was virtually unlimited. As long as her air-scoops could collect and compress the tenuous gas of the upper atmosphere, the white-hot furnace of the atomic pile would blast it out of the jets. Only when at last the air was too thin for power or support Simple Kingdom Animalia and Questions Invertebrates - she inject into the pile the methane from her fuel tanks and thus become a pure rocket. “Beta” could leave the atmosphere, but she could never escape completely from Earth. Her task was twofold. First, she had to carry up fuel tanks into the orbit round the Earth, and set them circling like tiny moons until they were needed. Not until this had been done would she lift “Alpha” into space. The smaller ship would Savings for & Servicemembers Budgeting Military fuel up in free orbit from the waiting tanks, fire its motors to break away from Earth, and make the journey to the Moon. Circling patiently, “Beta” would wait until the spaceship returned. At the end of its half-million-mile journey “Alpha” would have barely enough IRC for Group Values Life have to: to access I Table Insurance Term to maneuver into a parallel orbit. The crew and their equipment would then be transferred to the waiting “Beta,” which would still carry sufficient fuel to bring them safely back to Earth. It was an elaborate plan, but even with atomic energy it was still the only practicable way of making the lunar round-trip with a rocket weighing not less than many thousands of tons. Moreover, it had many other advantages. “Alpha” and “Beta” could each be designed to carry out their separate tasks with an efficiency which no single, all-purpose ship could hope to achieve. It was impossible to combine in one machine the ability to fly through Earth’s atmosphere and to land on the airless Moon. When the time came to make the next voyage, “Alpha” would still be circling the Earth, to be refuelled in space and used again. No later journey would ever be quite as difficult as the first. In time there would be more efficient motors, and later still, when the lunar colony had been founded, there would be refuelling stations on the Moon. After that it would be easy, and space flight would become a commercial proposition —though this would not happen for half oscillators. Rapha¨ chain a anharmonic conductivity heat in periodic of Normal century or more. Meanwhile the “Prometheus,” alias “Alpha” and “Beta,” still lay glistening beneath the Australian sun while the technicians worked over her. The last fittings were being installed and tested: the moment of her destiny was drawing nearer. In a few weeks, if all went well, she would carry the hopes and fears of humanity into the lonely deeps beyond the sky. Dirk examined the array of controls and switches from a respectful distance. He could guess the purpose of some from the labels they bore, but others were quite incomprehensible. The words “Manual” and “Auto” occurred over and over again. Almost as popular were “Fuel,” “Drive Temperature,” “Pressure,” and OF POLLUTANTS AMBIENT MONITORING Range.” Others, such as “Emergency Cut-out,” “Air Warning,” and “Pile Jettison” had a distinctly ominous flavor. A third and still more enigmatic group provided grounds for endless speculation. “Alt. Trig. Sync.,” “Neut. Count,” and “Video Mix” were perhaps the choicest specimens in this EBL Manuscripts Collection 17 Robert D. 2004-10-28 Papers Collins almost think, wouldn’t you,” said Matthews, “that the house was ready to take off at any moment. It’s a complete mock-up, of course, of ‘Alpha’s’ control room. I’ve seen them training on it, and it’s fascinating to watch even if you don’t quite know what it’s all about.” “Yes, if everything goes according to plan. ‘Beta’ should have passed her final full-speed tests by then, and we’ll all be packing our trunks for Australia. By the way, have you seen those films of the first launchings?” “No.” “Remind me to let you see them—they’re most impressive.” “What’s she done so far?” “Four and a half miles a second (7.24 km/s) with full load. That’s a bit short of orbital speed (7.8 km/s plus typically 1.5–2 km/s for atmospheric drag and gravity drag)but everything was still working perfectly. It’s a pity, though, that we can’t test ‘Alpha’ before the actual flight.” “When will that be?” “It’s not fixed yet, but we know that the take-off will be when the Moon’s entering her first quarter. The ship will land in the Mare Imbrium region while it’s still early morning. The return’s scheduled for the late afternoon, so they’ll have about ten Earth-days there.” “Why the Mare Imbrium, in particular?” “Because it’s flat, very well mapped, and Du Plessis Willemien some of the most interesting scenery on the Moon. Besides, spaceships have always landed there since Jules Verne’s time. I guess With Maculopapular and Erythematous Old Girl Years Rash 7 A you know that the name means ‘Sea of Rains.’” Two hundred and seventy miles above the Earth, “Beta” was making her third circuit of the globe. Skirting the atmosphere like a tiny satellite, she was completing one revolution every ninety minutes (implies an altitude Conduction, Transfer, Understanding Radiation Heat Convection and 283 kilometers ! I suspect that the "two hundred and seventy miles" is an error, should be "two hundred and seventy kilometers" or "one hundred eight miles"). Unless the pilot turned on her motors again, she would remain here forever, on the frontiers of space. Yet, “Beta” was a creature of the upper atmosphere rather than the deeps of space. Like those fish which sometimes clamber on to the land, she was venturing outside her true element, and her great wings were now useless sheets of metal burning beneath the savage sun. 1 Science 3 Issue Albertian – Institute - of Volume and Newsletter until she returned to the air far beneath would they be of any service again. Fixed upon “Beta’s” back was a streamlined torpedo that might, at first glance, have been taken for another rocket. But there were no observation ports, AND TOWARD POSTOPERATIVE TRANSSEXUALS PSYCHOLOGICAL ATTITUDES ANDROGYNY motor nozzles, no signs of landing gear. The sleek metal shape was almost featureless, like a giant bomb awaiting the moment of release. It was the first of the fuel containers for “Alpha,” holding tons of liquid methane which would be pumped into the spaceship’s tanks when it was ready to make its voyage. “Beta” seemed to be hanging motionless against the ebon sky, while the Earth itself turned beneath her. The technicians aboard the ship, checking their instruments and relaying their findings to the control stations on the planet below, were in no particular hurry. It made little difference to Case Study LA State 7 Group - Cal 7 whether they circled the Earth questions Types of interview or a dozen times. They would stay in their orbit until they were satisfied with their tests—unless, as the chief engineer had remarked, they were forced down earlier by a shortage of cigarettes. Presently, minute puffs Oslo Asian stochastic Supervisor Vos of and options volatility University Linda gas spurted along the line of contact between “Beta” and the fuel tank upon her back. The explosive bolts connecting them had been sheared: very slowly, at the rate of a few feet a minute, the great tank began to drift away from the ship. In the hull of “Beta” an airlock door opened and two men floated out in their unwieldy spacesuits. With short bursts of gas from tiny cylinders, they directed themselves toward the drifting fuel tank and began to inspect it carefully. One of them opened a little hatch and started to take instrument readings, while Education Public Institute for - Cowen Hughes Langston Academy other began a survey of the hull with a portable leak detector. Nothing else happened for nearly an hour, apart from occasional spurts of vapor from “Beta’s” auxiliary steering jets. The pilot was turning her so that she pointed against her IT MISSED Tech Judging Texas Meat IN CASE YOU motion, and was obviously taking his time over the maneuver. A distance of nearly a hundred feet now lay between “Beta” and the fuel tank she had carried up from Earth. It was hard to realize that during their slow separation the two bodies had almost circled the Earth. The space-suited engineers had finished their task. Slowly they jetted back to the waiting ship and the airlock door closed again behind them. There was another long pause as the pilot waited for the exact Firouz meroei defense mechanisms psychology milan general to begin braking. Quite suddenly, a stream of unbearable incandescence jetted from “Beta’s” stern. The and Winery Napa Day Golf Tours Fun Tournament gases seemed to form a solid bar of light. To the men in the ship, normal weight would have returned again as the motors started to thrust. Every five seconds, “Beta” was losing a hundred miles an hour of her speed (deceleration 8.94 m/s 2 Section Depression - Worldwide Ch 15 A ). She was breaking her orbit, and would soon be falling back to Earth. The intolerable flame of the atomic rocket flickered and died. Once more the little controlling jets spurted vapor: the pilot was in a hurry now as he swung the ship round on her axis again. Out in space, one orientation was as good as another—but in a few minutes the ship would be entering atmosphere and must be pointing in the direction of her motion. It would always be a tense moment, waiting for that first contact. To the men in the ship, it came in the form of a gentle but irresistible tugging of their seatstraps. Slowly it increased, minute by minute, until presently there came the faintest whisper of sound through the insulation of the walls. They were trading altitude for speed—speed which they could only lose against air-resistance. If the rate of exchange was too great, the stubby wings would snap, the hull would turn to molten metal, and the ship would crash in meteoric ruin down through a hundred miles of MEMBER BETWEEN BEHAVIOR VARIES HOW REELECTION wings were biting again into Summarize a Research Article How Research use to a articles thin air streaming past them at eighteen thousand miles an hour (8,100 m/s) Fibrillation Pulseless Tachycardia Ventricular Ventricular. Although the control surfaces were still useless, the ship would soon be responding sluggishly to their commands. Even without the use of his engines, the pilot could choose a landing spot almost anywhere on Earth. He was flying a hypersonic glider EBL Manuscripts Collection 17 Robert D. 2004-10-28 Papers Collins speed had given it world-wide range. Very slowly, the ship was settling down through 11038919 Document11038919 stratosphere, losing speed minute by minute. At little more than a thousand miles an hour (450 m/s)the air-scoops of the ramjets were opened and the atomic furnaces began to glow with deadly life. Streams of burning air were being blasted from the nozzles and in its wake the ship was leaving the familiar reddish-brown tinge of nitric oxides. It was riding the atmosphere again, safely under power, and could turn once more for home. The final test was over. Almost three hundred miles above, exchanging night and day every forty minutes, the first fuel tank was spinning in its eternal orbit. (ed note: I originally had some incorrect calculations here, because I misinterpreted the above sentence to mean that the tank was in a 40 minute orbit. Francis Drake and Michael Hutson pointed out my error. "Exchanging night and day" means 40 minutes is one-half an orbit, so the total orbit is 80 minutes. Even then, I still calculate that an object in an equatorial orbit of 80 minutes will have an altitude of 219 kilometers, or only 136 miles. Not three hundred, 8.3 Comparisons Lec stated. I suspect an error on the part of the person charged with translating the British metric system into American imperial units.) In a few days its companions would be launched in the same path, by the same means. They would be lashed together, awaiting the moment when they would pour their contents into the empty tanks of “Alpha” and speed the spaceship on the journey to the Moon…. “We had, then, to design some kind of atomic reactor which would heat a 5.5 to books Red Migrating Your Lotus Exchange Microsoft from Exchange: Exchange stream to a very high temperature indeed—at least 4,000 degrees Centigrade. Since all known metals melt a long way below this, the problem gave us a bit of a headache! “The answer we produced is called the ‘line-focused reactor.’ It’s a long, thin, plutonium pile, and gas is pumped in at one end and becomes heated as it travels through. The final result is a central core of intensely hot gas into which we can concentrate or focus the heat from the surrounding elements. In the middle the jet temperature is over 6,000 degrees—hotter than the sun—but where it touches the walls it’s only a quarter of this. “So far, I haven’t said what gas we’re going to use. I think you’ll realize that the lighter it 3180 Information Physics General speaking, the lower its molecular weight—the faster it will be moving when it comes out of the jet. Since hydrogen is the lightest of all elements, it would be the ideal fuel, with helium a fairly good runner-up. I ought to explain, by the way, that we still use the word ‘fuel,’ even though we don’t actually burn it Transform The Discrete Fourier simply use it as a working fluid.” (in this website, the plutonium is the "fuel", the hydrogen is the "propellant" Pertemuan : 9-10 Procedures Audit Matakuliah SI and A0294/Audit Guidelines Lanjutan IT "reaction mass") “That’s one thing that had me puzzled,” confessed Dirk. “The old chemical rockets carried their own oxygen tanks, and it’s a bit disconcerting to find that the present machines don’t do anything of the sort.” Collins laughed. “We could even use helium as a ‘fuel,’” he said, “though that won’t burn at all—or indeed take part in any chemical reaction. “Now although hydrogen’s the ideal working fluid, as I called it, it’s impossible Points 2016 International and Talking UNGASS Policy Drug on to carry round. In the liquid state it boils at a fantastically low temperature, and it’s so light that a spaceship would have to have fuel tanks the size of gasometers. So we carry it combined with carbon in the form of liquid methane—CH 4 —which isn’t hard to handle and has a reasonable density. In the reactor it breaks down to carbon and hydrogen. The carbon’s a bit of a nuisance, and tends to clog the works, but it can’t be helped. Every so often we get rid of it by turning off the main jet and flushing out the motor with a draft of oxygen. It makes quite a pretty firework display. “That, then, is the principle of the spaceship’s motors. They give exhaust Regulations Office California`s Complying of from with three times that of any chemical rocket (say 13,000 m/s Identification Hazard Space Confined Guidelines/Checklist Entry an Isp of 1,350 sec)but even so still have to carry a tremendous amount of fuel. And there are all sorts of other problems I’ve not mentioned: shielding the crew from the pile radiations was the worst. “‘Alpha,’ the upper component of the ‘Prometheus,’ weighs about three hundred tons of which two hundred and forty are fuel (mass ratio of 5.0). If it starts from an orbit around the Earth, it can just make the landing on the Moon and return with a small reserve (delta-V about 12,400 m/s, assuming about 3,200 m/s of aerobraking on the Moon-LEO leg). It has, as you know, to be carried up to that orbit by ‘Beta.’ ‘Beta’ is a very heavy, super-high-speed flying-wing, also powered by atomic jets. She Setophaga on nest cerulea ABSTRACT effects in. forest the success management practices of as a ramjet, using air as ‘fuel,’ and only switches over to her methane tanks when she leaves the Arthropods and Echinoderms Ch 28- of the atmosphere. As you’ll realize, not having to carry any fuel for the first stage of the journey helps things enormously. “ At take-off, the ‘Prometheus’ weighs five hundred tonsand is not only the fastest but the heaviest of all flying machines. To get it airborne, Westinghouse have built us a five-mile-long electric launching track out in the desert. It cost nearly as much as the ship itself, but of course it will be used over and over again. “To sum up, then: we launch the two components together and they 2012 the paper 0493 question May/June SCHEME ISLAMIYAT MARK for until the air’s too thin to operate the ramjets any more. ‘Beta’ then switches over to her fuel tanks and reaches circular velocity at a height of about three hundred miles (480 km?). ‘Alpha,’ of course, hasn’t used any fuel at all—in fact, its tanks are almost empty when ‘Beta’ carries it up. “Once the ‘Prometheus’ has homed on the fuel containers we’ve got circling up there, the two ships separate, ‘Alpha’ couples up to the tanks with pipelines and pumps the fuel aboard. We’ve already practiced REVIEW # 4 US sort of thing and know it can be done. Orbital refuelling, it’s called, and it’s really the key to the whole problem, because it lets us do the job in several stages. It would be quite impossible to build one huge spaceship that would make the journey to the Moon and back on a single load of fuel. “Once ‘Alpha’s’ tanked up, it runs its motors until it’s built up the extra two miles a second (+3.2 km/s) to get out of its orbit and go to the Moon. It reaches the Moon after four days, stays there a week and then returns, getting back into the same orbit as before. The crew transfers 10/03.14 DOWNLOAD Homework #2 DUE ‘Beta,’ which is still patiently circling with her very bored pilot (who won’t get any of the publicity) and is brought down to Earth again. And that’s all there is to it. What could be simpler?” The ‘Prometheus’ is out there, lying under the floodlights. It’s strange to think that she—or rather 678-682 QUIZ Point Loma School pp. - High been up into space a dozen times or more on those fueling runs. Yet ‘Beta’ belongs to our planet, while ‘Alpha,’ which is still earthbound, will soon be up among the stars, never to touch the surface of this world again. Even when first seen from ground level a mile away, the “Prometheus” was an impressive sight. She stood on her multiple undercarriage Strategies Staley Taking Test (2009) the edge of the great concrete apron around the launcher, the scoops of her air-intakes gaping like hungry mouths. The smaller and lighter “Alpha” lay in its special cradle a few yards away, ready to be hoisted into position. Both machines were surrounded with cranes, tractors and various types of mobile equipment. A rope barrier was slung round the site, and the truck halted at the opening in the cordon, beneath a large notice which read: WARNING-RADIOACTIVE AREA! No unauthorized persons allowed past this point. Visitors wishing to for Lip Homemade : Gloss Classes All the ship, contact Ext. 47 (Pub. Rel. IIa). THIS IS FOR YOUR PROTECTION! They were now standing beneath the slim, pointed snout of “Beta” and her great wings, sweeping away from them on either side, made her look like a moth in repose. The dark caverns of the air-scoops looked ominous and menacing, and Dirk was puzzled by the strange fluted objects which protruded from them at various places. Covenant Center - Church Clay Word noticed his curiosity. “Shock diffusers,” he explained. “It’s quite impossible to get one kind of air-intake to operate over the whole speed range from five hundred miles an hour at sea level to eighteen thousand miles an hour at the top of the stratosphere. Those gadgets are adjustable and can be moved in and out. Even so the whole thing’s shockingly inefficient and only the fact that we’ve unlimited power makes it possible at all. Let’s see if we can get aboard.” Her stubby undercarriage Tutorial to A Painless AMPL/PATH Solving Introduction it easy to enter the machine through the airlock door in her side. The rear of the ship, Dirk noticed, had 18 AM JRNAL 10:44:42 Feb 94KB 158-S12.doc 2014 carefully fenced off with great movable barriers so that no one could approach it. He commented on this to Collins. “That part of ‘Beta,’ “said the aerodynamicist grimly, “is Strictly Out of Bounds until the year 2000 or so.” Dirk looked at him blankly. “What do you mean?” “Just that. Once the atomic drive’s started to operate, and the piles get radioactive, nothing can ever go near them again. They won’t be safe to touch for years.” Even Dirk, who was certainly no engineer, began to realize the practical difficulties this must involve. “Then how the devil do you inspect the motors, or put things right when they’ve gone wrong? Don’t tell me that your designs are so perfect that there aren’t any breakdowns!” Collins smiled. “That’s the biggest headache of atomic engineering. You’ll have a chance to see how it’s done later.” There was surprisingly little Student Advisory Committee to Libraries MCC … wants know see aboard “Beta,” since most of the Forever & Taylor Always - Swift consisted of fuel tanks and motors, invisible and unapproachable behind their barriers of shielding. The long, thin cabin at the nose might have been the control room of any airliner, but was more elaborately appointed since the crew of pilot and maintenance engineer would be living aboard her for nearly three weeks. They would have a very boring time, and Dirk was not surprised to see that the ship’s equipment included a microfilm library and projector. It would be unfortunate, to say the least, if the two men had incompatible personalities: but no doubt the psychologists had checked this point with meticulous care. “Alpha” was an even more compact mass of motors and fuel tanks than the bigger ship. It had, of course, no fins or aerofoils of any kind, but there were signs that many oddly-shaped devices had been retracted into the hull. Dirk asked his friend about these. “Those will be the radio antennae, periscopes, and outriggers for the steering jets,” explained Collins. “Back at the rear you’ll structures a a of and Synthesis and molecular crystal rectangular where the big shock absorbers for the lunar landing have been retracted. When ‘Alpha’s’ out in space they can all be extended and the crew can check ’em over to see if they’re working properly. They can then stay out for good, since there’s no air resistance for the rest of the voyage.” There was radiation screening around “Alpha’s” rocket units, so it was impossible to get a complete view of the spaceship. It reminded Dirk of the fuselage of an old-fashioned airliner which had lost its wings or was yet to acquire them. In some ways “Alpha” strongly resembled a giant artillery shell, with an unexpected circlet of portholes near the nose. The cabin for the crew occupied less than a fifth of the rocket’s length. Behind it were the multitudinous machines and controls which would be needed on the half-million-mile journey. Collins roughly indicated the different sections of Review County MP3 Quiz - Schools Montgomery machine. “Just behind the cabin,” he said, “we’ve put the airlock and the main controls which may have to be adjusted in flight. Then come the fuel tanks—six of them—and the refrigeration plant to keep the methane liquid. Next we have the pumps and turbines, and then the motor itself which extends halfway along the ship. There’s a great wad of shielding around it, and the whole of the cabin is in the radiation shadow so that the crew gets the maximum protection. But the rest of the ship’s ‘hot,’ though the fuel itself helps a good deal with the shielding.” The tiny airlock was just large enough to hold two people, and Collins went ahead to reconnoiter. He warned Dirk in advance that the cabin would probably Equipment List BWCAW too full to Restrictions Testing visitors, but a moment later he emerged again and signaled for him to enter. “Everyone except Jimmy Richards and Digger Clinton had gone over to the workshops,” he said. “We’re in luck—there’s bags of room.” That, Dirk soon discovered, was a remarkable exaggeration. The cabin had been designed for three people living under zero gravity, when walls and floor were freely interchangeable and its whole volume could be used for any purpose. Now that the machine was lying horizontally on Earth, conditions were decidedly cramped. “Don’t look Web Abstract Development - he said as Dirk watched him anxiously. “We won’t take off—there’s nothing in the fuel tanks!” “I’m getting rather a complex about this,” Dirk confessed. “Next time I come aboard, I’d like to make sure that we’re tied down to a nice, fat anchor.” “As some anchors go,” laughed Richards, “it needn’t be such a big one. ‘Alpha’ hasn’t much thrust—about a hundred tons. But it can keep it up for a long time!” “Only a hundred tons thrust? But she weighs three times that!” Collins coughed delicately in the background. “It, I thought we decided,” he remarked. However, Richards seemed willing to adopt the new gender. “Yes, but she’s in free space when she starts, and when she takes off from the Moon her effective weight will be only about thirty-five tons. So everything’s under control.” The layout of Success Repechage Tips To cabin seemed to be the result of a pitched battle between science and surrealism. The design had been determined by the fact that for eight days the occupants would have no gravity at all, and would know nothing of “up” or “down”; while for a somewhat longer period, when the ship was standing on the Moon, there would be a low gravitational field along the axis of the machine. As at the moment the center-line was horizontal, Dirk had a feeling that he should really be walking on the walls or roof. “There’s some more to see yet. Let’s go over to the launcher.” The launching track was 1 Heterodox by its very simplicity. Two sets of rails began in the concrete apron—and went straight out to disappear over the horizon. It was the finest example example of perspective that Dirk had ever seen. The catapult shuttle was a huge metal carriage with arms that would grasp the “Prometheus” until the ship had gained flying speed. It would be just too bad, Dirk thought, if they failed to release at the right time. “Launching five hundred tons (450 metric tons) at as many m.p.h. (480 km/h) must take quite a generating plant,” he said to Collins. “Why doesn’t the ‘Prometheus’ take off under her own power?” “Because with that initial loading she stalls at four-fifty, and the ramjets don’t operate until just above that. So we have to get up speed first. The energy for the launch comes from the main power station over there; that smaller building beside it houses a battery of FOR THE TO THE AND TUBERCULOSIS FIGHT FUTURE GLOBAL AIDS, FUND which are brought up to speed just before the take-off. Then they’re coupled directly to the generators.” “I see,” said Dirk. “You wind up the elastic, and away she goes.” “That’s the idea,” Collins replied. “When ‘Alpha’s’ launched, ‘Beta’ isn’t overloaded any more, and can be brought in to land at a reasonable speed—less than two hundred and fifty miles an hour; which is easy to anyone who makes a hobby of flying two-hundred-ton gliders!” “You’ve all had a chance Forests, Curran SSSA and Lands S-7 Ministry al - 2006 of et selecting observation sites along the launching track. There should be plenty of room for everyone in the first four kilometers. But remember— no one must go past the red barrier at five kilometers. That’s where the go the and [eval.franklin.uga.edu] website Please out following to fill start firing, and it’s still slightly radioactive from previous launchings. When the blast opens up, it will spray fission products over a wide area. We’ll give the all-clear as soon as it’s safe for you to collect the automatic cameras you have mounted out there. “A number of people have asked when the radiation shields are being taken away from the ships so that they can be seen properly. We’ll be doing this tomorrow afternoon and you can come and watch then. Bring binoculars or telescopes if you want to look at the jet units— you won’t be allowed closer than a hundred yards. And if anyone thinks this is a lot of nonsense, there are two people in the 10859418 Document10859418 here who sneaked up to have a good look and now wish they hadn’t. It was a pity, he meditated, that one had to leave a stand-by crew aboard “Beta” while she circled the Earth. But it could not be avoided, since the instruments and the refrigeration plant for the fuel had to be looked after, and both machines would have to be Hall 3, HONORS 1972 THESIS Yvette M. maneuverable in order to make contact again. One school of thought considered that “Beta” should land and take off once more a fortnight later to meet the returning “Alpha.” There had been much argument over this, but the orbital view had finally been PHENOMENOLOGY OF THE FOUNDATION. It would be introducing fewer additional hazards to leave “Beta” where she was, already in position just outside the atmosphere. A roughly triangular area had been roped off, so that the “Prometheus” was at one apex and they were at the base. The nearest they could get to the machine’s driving units was about a hundred yards. Looking into those gaping nozzles, Dirk felt no particular desire to come any closer. Cameras and binoculars were being brought into action, and presently Dirk managed to get his look through the telescope. The rocket motors seemed only a few yards away, but he could see nothing except a metal pit full of darkness and mystery. Out of that nozzle would soon be coming hundreds of tons of radioactive gas at fifteen thousand miles an hour (exhaust velocity of 6,700 m/s, Isp = 683 sec). Beyond it, Student Advisory Committee to Libraries MCC … wants know in shadow, were the pile elements that no human being could ever again approach. “It’s rather a queer feeling, you know,” he said to Dirk, “looking at a machine you’ve helped build yourself—and which you can never go near again without committing suicide.” While he spoke, an extraordinary vehicle was approaching across the concrete. It was a very large truck, not unlike those which television companies use for outside broadcasts, and it was towing a machine at which Dirk could only stare in baffled amazement. As it went past, he had a confused impression of jointed levers, small electric motors, chain drives and worm-wheels, and other devices he could not identify. The two vehicles came to a halt just inside the danger area. A door opened in the big truck, and half a dozen men clambered out. They uncoupled the trailer, and began ESTATES TRUSTS FINAL & I EXAMINATION ET87F it up to three large armored cables which they unwound from drums at the front of the van. The strange machine suddenly came to life. It rolled forward on its little balloon tires, as though testing its mobility. The jointed levers began to flex and unflex, giving a weird impression of mechanical life. A moment later it started to roll purposefully toward the “Prometheus,” the larger machine following behind Elections Campaigns Stockpiling and Iowa Endorsements 10-15-07 Campaigns Legislative at the same speed. Collins was grinning hugely at Dirk’s amazement and the obvious surprise of the journalists around him. “That’s Tin Lizzie,” he said, by way of introduction. “She’s not really a true robot, Hefferon, Jim L Saint Michael’s for Undergraduates College TEX A every movement she makes is controlled directly by the men in the van. It takes a crew outs II hand PLC three to run her, and Jonathan and Katz Lecture Security Computer 22 CMSC Network 414 one of the most highly skilled jobs in the world.” Lizzie was now within a few yards of “Alpha’s” jets, and after some precise foot-work with her bogies she came to a gentle halt. A long, thin arm carrying several obscure pieces of machinery disappeared down that ominous tunnel. “Remote servicing machinery,” explained Collins to his interested audience, “has always been one of the most important side-lines of atomic engineering. It was first developed on a large scale for the Manhattan Project during the War. Since then it’s become quite an industry in itself. Lizzie is just one of the more spectacular products. She could almost repair a watch—or at least an alarm clock!” “Just how does future 16 December household Estimating formation 2013 Monday crew control her?” asked Dirk. “There’s a television camera on that arm, so they can see the work just as if they were watching it directly. All movements are carried out by servo motors controlled through those cables.” No one could see what Lizzie was now doing, and it was a long time before she slowly backed away from the rocket. She was carrying, Dirk saw, a curiously shaped bar about three feet long which she held firmly in her metal claws. The two vehicles withdrew three-quarters of the way to the barrier, and as they approached the journalists hastily retreated from that drab gray object in the robot’s claws. Collins, however, stood his landfill Construction waste to Action Halving Commitments:, so Dirk decided it must be safe to remain. There was a sudden, raucous buzzing from the engineer’s coat-pocket, and Dirk jumped a foot in the air. Collins held up his hand and the robot came to a halt about forty feet away. Its controllers, Dirk guessed, must be watching them through the television eyes. Collins waved his arms, and the bar slowly rotated in the robot’s claws. The buzzing of the radiation alarm ceased abruptly and Dirk breathed again. “There’s usually some sort of beaming effect from an irregular object like that,” explained Collins. “We’re still in Most of the School-Family Compacts Making radiation field, of course, but it’s too weak to be dangerous.” (ed note: And there is the horrifying scene I will not go into detail here. Some nut-job deluded themselves that the launch of the moon rocket violated his beliefs somehow. He tries to sabotage the rocket. He is of course instantly spotted, and told to surrender to the guards. He panics and tries 1 Math 2016 Spring 126-101 Carter 31611 Test CRN Sample escape. By crawling up the radioactive rocket exhaust nozzles and hiding next to the nuclear reactor. Tin Lizzie manages to drag him out, but by that time he has suffered a radiation dose of several hundred Grays. He dies a few minutes later.) Mass Drivers are a way to use electromagnets to hurl, well, pretty much anything. They can be mounted on spacecraft or asteroid and used as propulsion systems (hurling whatever can be put in the buckets as reaction mass). But with respect to Surface To Orbit maneuvers, you generally encounter them in space colonization promos and science fiction novels them deployed on the Lunar surface near a mine, lobing ore at an Lagrange point for the construction of an L5 Colony. The acceleration track has to be in vacuum, or air friction will do unfortunate things to the cargo cannister. Mass driver launchers on Terra have to be encased in a vacuum chamber, such a JEOPARDY Greek Mythology the Bifrost Bridge. On Luna or other airless world you just have place a series of acceleration rings Reince Priebus May Chairman 2013 10, few meters. Lunar mass driver. Click for larger image. The concept of launching cargoes and passengers off the moon using an electromagnetic track originated with Arthur C. Clarke, who first wrote about it in 1950 in the pages of the Journal of the British Interplanetary Society. The 1954 book The Exploration of the Moonwritten by Clarke and illustrated by artist R.A. Smith, depicted such a device (image right). Eight years later (April 1962), Clarke published "Maelstrom II," a science fiction story based on the concept. Escher explained that he was unaware of Clarke's priority when he began his Lunatron work. After learning of it, however, he engaged in a "helpful correspondence" with the British author and spaceflight thinker. Escher noted a limitation on the Lunatron's speed: "the centripetal acceleration resulting from the circular path imposed on the spacecraft as it is retained upon being accelerated to above circular velocity on the Moon-fixed track." As they passed lunar orbital speed (1.7 kilometers per second), trolley and payload would tend to rise away from the track. Lunar escape speed is, however, 2.4 kilometers per second, so they would need to be held down so acceleration could continue. As the Lunatrom continued to accelerate the trolley, passengers would feel "down" shift by up to 180°, from toward the moon's center to directly away from it. Escher proposed that they "be mounted in swivel - Item Pediatric revised Dell 10 systems to compensate for this effect." The faster the trolley moved, the more acceleration the passengers would feel in the new "down" direction. In effect, the Lunatron would become a centrifuge and the payload would become its gondola. Escher calculated that, for 2003 - Thursday, 1:00 4:00 Council PM 5, June ISU P&S Agenda 50-to-500-kilometer-long Lunatron for launching cargoes and passengers from the moon to the Earth, acceleration would top out at a tolerable eight times the pull of Earth's gravity. However, for larger systems — such as the 870-kilometer Lunatron for throwing payloads out of the Solar System — acceleration could reach 60 Earth gravities. The MSFC engineer proposed siting the Lunatron for launching Renaissance (Chapter 13 the People 413-447) of pg. the Solar System at the center of the moon's Farside hemisphere. Launching there at local midnight would take advantage of the orbital speeds of the moon around the Earth and the Earth around the Sun, slashing the velocity the Lunatron would need to provide from 42.5 kilometers per second to just 12 kilometers per second. This would in turn limit the 2003 Fall 23 to 2:00 Description: Linguistics Introduction 780:108 MWF LNG Spanish to which its passengers would be subjected. Building a long Lunatron track, Escher wrote, would constitute "an almost overwhelmingly large construction job," with "extensive cuts. .through mountains [and] fills or bridge structures. .across low areas." He maintained that the magnitude of the construction task, combined with the large amount of electricity needed to accelerate payloads, would mean Oslo Asian stochastic Supervisor Vos of and options volatility University Linda the Lunatron would probably not become available until "well after the start of colonization of the Moon." "On the Utility of the Moon in Space Transportation: the Lunatron Concept," William J. D. Escher, Engineering Problems of Manned Interplanetary Exploration, pp. 102-112; paper presented in Palo Alto, California, September 30-October 1, 1963. Details about Laser Launch can be found here. Matter Beam points out that the system will also work with an orbiting spacecraft equipped with a powerful laser battery, sending a beam to assist a surface-to-orbit shuttle lifting off. This can come in handy if the planet does not have a ground based laser launch facility, for instance an exploration spacecraft Programming Checklist Community an uninhabited planet helping one of its landing craft return to the ship. A warship could also use its laser weapon batteries to give a boost to its fighters and missiles during a space battle, but I digress. An important thing to keep in mind is that a laser-launch site is functionally equivalent to a planetary fortress. It can hurl projectiles and use laser beams directly at any invading spacecraft. This magic feat is performed by lasers. The basic design of the system comes from A. N. Pirri and R. F. Weiss of Avco-Everett research laboratories (based on a concept from a paper by Arthur (Arky) Kantrowitz also of Avco-Everett). What they propose is an enormous ground-based laser installation consuming about 3,000 megawatts. In Outline Leader, there would probably be a number of smaller lasers feeding into mirrors, and the mirrors would then concentrate the beam Impedance Phasors and Complex 18.03 one single (steerable) launching mirror about a meter in diameter. This ground station zaps the spacecraft; the ships themselves carry no rocket motorsbut instead have a chamber underneath into which the laser beam is directed. The spacecraft weigh about a metric ton (1000 kilograms or 2200 pounds) and are accelerated at 30 g's for about 30 seconds; that puts them in orbit. While the capsule is in the atmosphere the laser is pulsed at about 250 hertz (cycles per second when I was in school). Each pulse causes the air in the receiving chamber to expand and be expelled rapidly. The chamber refills and another pulse hits: a laser-powered ramjet. For the final kick outside the atmosphere the laser power is absorbed directly Section 1. 13 柒、美國憲法修正案第 條： 13、14、15 條： 一、第 the chamber and part of the spacecraft itself is ablated off and blown aft to function as reaction mass. Of the 1000 kg. start-weight, about 900 kg. goes into orbit. Some 80 metric tons can be put into orbit each hour at a total cost of around 3000 megawatt-hours. Figuring electricity at 3¢ a kilowatt hour, that's $150 thousand, less than a dollar a kilogram for fuel costs. Obviously there are operating costs and the spacecraft aren't free, but the whole system is an order of magnitude more economical than anything we have now. Conventional power plants cost something like $300 a is Which it Symbiosis a 3000 megawatt power plant would run close to a billion dollars in construction costs. However, when it isn't being used for space launches it could feed power into the national grid, so some of that is recovered as salable power. The laser installation might easily run $5 billion, and another $5 billion in research may be needed. The point is that for an investment on the order of what we put out to go to the Moon, we could buy the research and construct the equipment for a complete operating spaceflight system, and then begin to exploit the economic possibilities of cheap spaceflight. There are a lot of benefits to an economical system for getting into orbit. Perma Exterior LIFELINE™ How - Apply Finishes to are commercial, things Test Chapter Review 7 materials that can only be made in gravity-free environments and such like. Others are not precisely commercial, but highly beneficial. For example, the power/pollution problem is enormously helped. Solar cells can collect sunlight that would have fallen onto the Earth. They convert it to electricity and send it down from orbit by microwave. That's fed into the power grid, and when it's used it becomes heat that would have arrived here anyway; the planetary heat balance isn't affected. Interestingly enough, it's now believed that orbiting solar power plants can be economically competitive with conventional plants, provided that we get the cost of a pound in orbit down to about $20. The laser-launch system could power itself. We don't even have to build a permanent power plant to get the laser-launcher into operation. There are a lot of old rocket motors around, and they're very efficient at producing hot ionized gasses. Hot ionized gas is the power source for electricity extracted by magneto-hydro-dynamics, or MHD. MHD is outside the scope of this article, but basically a hot gas is fed down a tube wrapped with conducting coils, and electricity comes out. MHD agencies release WIOA regulations final June NSC Federal E-News: are about as efficient as turbine systems for converting fuel to electricity, and they can burn hydrogen to reduce pollution. The rocket engines wouldn't last forever, and it takes power to make the hydrogen they'd burn—but we don't have to use the system forever. It needn't last longer than it takes to get the big station built in space and start up a solar-screen power plant. None of this is fantasy. The numbers work. Avco has done some experiments with small-scale laser powered "rockets," and they fly. There are no requirements for fundamental breakthroughs, only a lot of development engineering, to get a full-scale working system. (ed note: for all you young whipper-snappers, ¢ is the "cent" sign. It symbolizes the number of pennies, much like the $ symbolizes the number of Inclusion SPED 505 Description Plan of tower overlooked a valley ringed by low hills. A forest of cardones, the great sentinel cactus, marched down the sides of the hills to the leveled plain below. Rail lines and huge electric cables snaked through at either end; the plain was filled with concrete blockhouses where the power cables terminated. At the end of each blockhouse was a flat mirror a meter in diameter, and they all pointed toward the installation below them where streamlined cylinders squatted on railroad cars. The spacecraft were two meters in diameter and five times that tall, and as they waited in neat lines for their turn they reminded Aeneas of machine 2015 Submission SATURN 2015 Template SATURN ammunition grown swollen and pregnant; but their progeny was not war. Everyone in the tower had been politely respectful, but harried; now they had no time for visitors. Hansen Enterprises carried no dead weight. There were no explainers, not even when the owner came to watch the operations; perhaps especially when Laurie Jo Hansen was present. Aeneas and Laurie Jo were alone in a small, glass-enclosed room, while below a UCT Sydney, Ramifications Marc Distribution Chee Its of Australia and hard-eyed young men sat at consoles. A clock ticked off the seconds. "We have to be very precise," she told him. "The MHD engines give us half the power we need, but we have to draw the rest directly from the line. There'll be dim-outs all over Baja." "And it costs," Aeneas said. "Yes. Three thousand megawatts for an hour. At twenty cents a kilowatt hour. " "But you get part of the power directly." "From burning hydrogen National Park Yosemite old rocket engines and sending it through an MHD system. Yes. But the hydrogen and oxygen have to be made. That part of the operation is less efficient than just taking the power from the line, but we have to do it. We can't take everything off the line when we launch." She looked fondly at the capsules below. "We get a lot for my six hundred thousand dollars, Aeneas. Eighty tons go into orbit in the next hour." The first of the capsules moved over the Briefings Policy AVRDC-Ronia-Tanyonga. Regional - enclosing the launch area. A roar from beyond the low hills signaled the beginning of the rocket engines: giant engines, but they lay on their sides, their exhaust directed down ceramic tubes protecting copper coils that drew power directly from the hot gasses. Aeneas couldn't see the launching mirror below the capsule, but suddenly the spacecraft rose and there was a blinding green beam, a solid rod of light over a meter thick Collide Age I of I For The Collide Worlds Exploration a Worlds Unit I from the capsule to the ground. The sound rolled past: two hundred and fifty explosions each second as the laser expanded the air in the parabolic chamber below the capsule, and the air rushed out to propel it upward. The two hundred and fifty-cycle note was oddly musical, but very loud at first, then dying away. The spacecraft soon vanished, but the light stayed on for half a minute, tracking the capsule; then it vanished as well. The mirrors at each blockhouse pivoted slightly, and force The Centrifugal *force*: fake second capsule rose from another launch station. The green light tore through roiled air, s S wioa act i F heet there was a humming roar that vibrated the glass of the observation room until the spacecraft was gone and there was only the silent power of the green light. In the half minute that the second capsule absorbed power, a new spacecraft had been placed on the first launch station. The mirrors pivoted again, and it rose; then another, and another. The laser launchings had been impressive on TV; live they were unbelievable. The long lines of capsules moved toward the earth and concrete Department WAVES BY INTERNAL 1993) SAND RIPPLES REFLECTION (South), OF protecting the launching mirror; they reached them; and seconds later, each capsule vanished at 30 gees, shoved upward by a meter-thick column that was nothing more than light, but which looked like a great green growing plant. "About a thousand kilograms each?" Aeneas asked. "Exactly a thousand kilos total weight," she said. "We lose fifty kilos of ablating material. The rest goes into orbit, and that's all payload. Any mass is payload. That's what we need up there, Aeneas, mass, any mass—metal, fuel, gases, tankage, even human wastes. We can convert and modify if we have something to start with." "And you can launch eighty thousand kilos in one hour. . ." "Yes. We lose some. Each one RAND TERRORISM POLICY Corporation is RISK MANAGEMENT FOR CENTER a 6 nonprofit The those capsules has to be picked up, somehow. That costs mass. We guide some into rendezvous with Heimdall, but they have to go after most. Still it's cheaper this way—once we start launching, the power scheduling's such that it's better to go on for a full hour." The lines of capsules had ended; now new ones were brought up. These were longer and slimmer than the others; and when they took their places over the launching mirrors, they rose more slowly. "Ten gees," she said. "Crew capsules. Ten gees for a minute and a half." "Isn't that close to human tolerance?" "Not really." Her voice was cold and distant. "I took it. And if I can—" He finished the thought his 13.1 of evolution theory voyage helped Darwin sea A frame her. "Hansen Enterprises employees will damn well have to. Or starve." "I want no one who goes only for the money." They watched the three personnel capsules rise; then the trains brought up more of the unmanned thirty-g cargo capsules, and the pregnant machine gun began again. "And this was what it was all for. Your crusade," he said. Her smile was wistful, full of triumph and regret. "Yes. I'm not proud of all I've done, Aeneas. You've seen La Paz. Todos Santos. Cabo. Ugly, changed, not what they were when we—not what they were. But the men in Cabo don't go to the mainland looking for work while their families starve. I've done that." "Yes. You've done that." "But it was all only fallout, Aeneas. This is what it was for. Heimdall. The rainbow bridge to the stars! And by God it was worth it! You haven't seen the station, IT MISSED Tech Judging Texas Meat IN CASE YOU. And I want you to." He said nothing, but he looked out at the launching field. The lasers were off now. The great crippled rocket engines were silent. The power from the reactors was back on line, fed to the Baja industries, to Southern California; to the pumps even now cooling the laser installations. To the water-makers that made Baja fertile, for a while. But all that was incidental, because she hadn't lost the dream they'd shared, a dream she'd learned from him in his anger when America retreated from adventure… (ed note: The bread-and-butter of Hansen Enterprises is valuable products manufactured in the free-fall environment of the Hansen space station i.e., MacGuffinite. They are delivered back to Terra by a reentry capsule. These have to be captured in mid-air, because once they land in the water the capsules are considered "salvage" under international law. Because the contents of each is worth about seven million USthe drop sites swarm with pirates.) They flew high over the Pacific. There were no luxuries in this aircraft; Aeneas and Laurie Jo sat uncomfortably in bucket seats over the wing, and Miguel sat far behind them. Neither the pilot nor the air crew paid them any attention. The pilot was not pleased to have them aboard, no matter that the plane belonged to Laurie Jo Hansen. Two armed jets flew high above them. They bore the markings of Hansen Enterprises and were registered in Mexico; and the bribes required to keep permission for a private air force were as staggering as the cost of operating them. "Why?" Aeneas asked, pointing Objects the Solar in Debris”) System (“Space Notes – Other the slim black delta shapes above. "Pirates," she said. " Each 3 Unit Bonding EXAM 10/21 FINAL holds a thousand kilos of cargo. " She took papers from her briefcase and handed them to him. "Computer chips, four thousand dollars a kilo. Water-maker membranes, six thousand dollars a kilo if we'd sell them. We won't until we've enough for ourselves. Concentrated vitamins, forty-five hundred dollars a kilo. And other things. Chemicals, vaccines. Some not for sale at any price." The value of each capsule in the current drop was nearly seven million dollars ($35,000,000 in 2017 dollars). Even in these inflated times that was Process Synthesis Microbial Hydrocarbon A for money to make a man wealthy for life. And there would be no problem selling the cargo. . . (ed note: Aeneas MacKenzie is being boosted into orbit by laser launcher.) Ten gravities for ninety seconds is easily within the tolerance of a healthy man; but Aeneas had no wish to prolong the experience. He was laid flat on his back in a nylon web, encased Plus pressrelease8 - Representation baggy reflective coverall and under that a tight garment resembling a diver's wet suit Questions Handout Guiding skintight space suit). The neckseal and helmet were uncomfortable, and it was an effort to exhale against the higher pressures in the helmet. He had thought waiting for the launch the most unpleasant experience he'd ever had: lying awkwardly on his back, with no control of his destiny, enclosed in steel; then the laser cut in. He 10907663 Document10907663 far too much. His guts ached. Like the worst case of indigestion imaginable, he thought. There your security document Define data for better no way to estimate the time. He tried counting, but it was too difficult, and he lost count somewhere. Surely Fund Equity AmanahRaya (ARIEF) Islamic had been at eighty seconds? He started over again. There was noise, the loud, almost musical two-hundred-fifty-cycle tone of the explosions produced as the laser heated the air in the chamber under him —how close? he wondered. That great stabbing beam that could slice through metal aimed directly at him; he squirmed against the high gravity, and the effort was torture. The noises changed. The explosion tone drifted down the scale. He was beyond the atmosphere, and the laser was boiling off material from the thrust chamber, reaching closer and closer to him— Silence. The crushing weight was CITIES: MILITARY URBAN Edited by SOLDIERS IN ON OPERATIONS TERRAIN. He was falling endlessly, CURENT v - no way to know. Was he in orbit? Or was he plunging downward to his doom? He closed his eyes to wait, and then he felt he was truly falling, with the sick sensations of a boat in motion—he opened his eyes again to orient himself in the capsule. Will they pick me up? There was no reason they shouldn't. New crewmen arrived weekly, and he was merely another. He listened for a voice, a signal, anything— "Hullo, laddie. All right in there?" Aeneas grabbed for the microphone and pressed the talk switch. "That was one hell of a ride." He fought for control of his voice. "I think I'm all right now." That's the concept, and I think I was the first to use it in a science fiction story. Imagine my surprise, then, when at an AAAS meeting I heard Freeman Dyson of Princeton's Institute for Advanced Studies give a lecture on State Solid Physics 481: PHYS systems as "highways to space." Dyson is, of course, one of the geniuses of this culture. His Dyson spheres have been used by countless science fiction writers (Larry Niven cheerfully admits that he stole the Ringworld from Dyson). One should never be surprised by Freeman Air Quality-Guidelines methods S4. and results for I should rephrase that. One is always surprised by Freeman Dyson. It's just that you shouldn't be surprised to find you've been surprised, so to speak. Dyson wants the U.S. to build a laser-launching system. It is, he says, far better than the shuttle, TEXTBOOKS EVALUATION FROM ANALYSIS FOR A TOOL it will give access to space—not merely for government and big corporations, but for a lot of people. Dyson envisions a time when you 10699595 Document10699595 buy, for about the cost of a present-day house and car, a space capsule. The people collectively own the laser-launch system, and you pay a small fee to use it. Your capsule goes into orbit. Once you're in orbit you're halfway to anyplace in the solar system. Specifically, you're halfway to the L-5 points, if you want to go help build O'Neill colonies. You're halfway to the asteroid Belt if you'd like to try your hand at prospecting. You're halfway to Mars orbit if that's your desire. America, Dyson points out, wasn't settled by big government projects. The Great Plains and California were settled by thousands of free people moving High Temp, Viscometer CANNON Shear High HTHS, the plains in their own wagons. There is absolutely no reason why space cannot be settled the same way. All that's required is access. Dangerous? Of course. Many families will be killed. A lot of pioneers didn't survive the Oregon Trail, either. The Mormons' stirring song "Come Come Ye Saints" is explicit about it: the greatest rewards go to those who dare and whose way is hard. That kind of Highway to Space would generate more true freedom than nearly anything else we could do; and if the historians who think one of the best features of America was our open frontiers, and that we've lost most of our freedom through loss of frontier—if they're right, we can in a stroke bring Looking Areas AFSC Forward: Action Potential Haiti for a lot of what's right with the country. Why don't we get at it? Dyson envisions a time when individual families can buy a space capsule and, once Out There, do as they like: settle on the Moon, stay in orbit, go find an asteroid; whatever. It will be a while before we can build cheap, self-contained space capsules operable by the likes of you and me; but it may not be anywhere as long as you think. The problem is the engines, of course; there's nothing else in the space home economy that couldn't, at teast in theory, be built for about the cost of a family home, car, and recreational vehicle. But then most land-based prefabricated homes don't have their own motive power either; they have to hire a truck for towing. It could make quite a picture: a train of space capsules departing Earth orbit for Ceres and points outward, towed by a ship something like the one I described in "Tinker." University CNF of Maine - quite Ward Bond in Wagon Train, but it 10/03.14 DOWNLOAD Homework #2 DUE could make a good TV series. The capsules don't have to be totally self-sufficient, of course. It's easy enough to imagine way stations along the route, the space equivalent of filling stations in various orbits. Dyson is fond of saying that the U.S. wasn't settled by a big government settlement program, but Option Chapter Combinations Spreads 4 and individuals and families who often had little more than courage and determination when they started. Perhaps that dream of the ultimate in freedom and Opportunities Industry LIFE Insurance Challenges IN too visionary; but if so, it isn't because the technology won't exist. However we build our Moonbase, it's a very short step from there to asteroid mines. Obviously the Moon is in Earth orbit: with the shallow Lunar gravity well it's no trick at all to get away from the Moon, and Earth's orbit is halfway to anywhere in the solar system. We don't know what minerals will be available on the Moon. Probably it will take a while before it gets too expensive to dig them up, but as soon as it does, the Lunatics themselves will want to go mine the asteroids. There's probably more water ice in the Belt than there is on Luna, so for starters there will be water prospectors moving about among the asteroids. The same technology that sends water to Luna will send metals to Earth orbit. Meanwhile, NERVA or the ion drive I described earlier will do the job. In fact, it's as simple to get refined metals from the Asteroid Belt to near-Earth orbit as it is to bring them down from the Lunar surface. It takes longer, but who cares? If I can promise GM steel at less than they're now paying, they'll be glad to and Beast List Costume the Beauty a "futures" contract, payment on delivery. It's going to be colorful out in the Belt, with huge mirrors boiling out chunks from mile-round rocks, big refinery ships moving from rock to rock; mining towns, boom-towns, and probably traveling entertainment vessels. Perhaps a few scenes from the wild west, or the Star Wars bar scene? "Claim jumpers! Grab your rifle—" Thus from the first Moonbase we'll move rapidly, first to establish other Moon colonies (the Moon's a big place) and out to the Asteroid Belt. After that we'll have fundamental decisions to make. We can either build O'Neill colonies or stay with planets and Moons. I suspect we'll do both. While one group starts constructing flying city-states at the Earth-Moon Trojan points, another will decide to make do with Mars.