Aucbvax.5421 fa.space utzoo!decvax!ucbvax!space Wed Dec 9 03:49:46 1981 SPACE Digest V2 #54 >From OTA@S1-A Wed Dec 9 03:42:46 1981 SPACE Digest Volume 2 : Issue 54 Today's Topics: Arthur Kantrowitz talk at Harvard getting there (high power) Galileo cut ---------------------------------------------------------------------- From: BRUC@MIT-ML Date: 12/08/81 12:27:28 Subject: Arthur Kantrowitz talk at Harvard BRUC@MIT-ML 12/08/81 12:27:28 Re: Arthur Kantrowitz talk at Harvard To: Space-Enthusiasts at MIT-MC Last night, Arthur Kantrowitz gave a talk at Harvard titled, "What is Holding Back the Utilitization of Outer Space?". He made a number of provocative statements that should prove interesting to those (such as myself) who hadn't heard them before. He opened his talk by looking at societal environment for space utilization. In the thirties, Bernal, a physicist, foresaw huge numbers of people living in spheres in space colonies. At the time, getting into orbit was the problem. Now, we can get into orbit, but the future for space is cloudly (much to all our chagrin). NASA and the politics behind its expenditures provide a partial explanation of what's happening. In his view, the goal of making space reasonably accessible was secondary to goal of pumping money and high technology into the states which held Lyndon Johnson's allegiance, particularly Texas. Second, he implied that the pursuit of safety in the Apollo program may have been excessive. He pointed out that the only men who were killed died in a safety exercise rather than in space. He then considered the financial and energetic barriers to getting into low earth orbit. If you calculate the kinetic energy of one pound at orbital velocity 100 miles up, you get an energy value of 4.5 kwh/lb (25 cents!!). The shuttle will cost in the high hundreds of dollars per pound. Amortizing the development cost ($10 billion) of the shuttle will take on the order of 1000 flights because the savings in cost is only a couple of hundred dollars per pound. What is wrong with the shuttle, then? First, it has wings. If an orbiter had a more compact shape, the reentry would not be such a problem. It would land by parachute and the final impact would be dissipated by some sort of crushable material. Such a design would not preclude reusability of most of the hardware. Why does it have wings? Politics. Only the aerospace companies would get a contract to build it. The shuttle keeps NASA in business these days; without it, they'd be a shell. What are better ways? He suggested three. All of these are "railways to space" as he put it. Without such a system, space will never be well utilized. 1) The big dumb booster. A very large booster that could be built with standard metals (he suggested the Chicago Bridge and Iron Works as prime contractor). He didn't give many details on it. 2) Mass driver to orbital speeds on earth. He suggested that a properly designed projectile (telegraph poles) would not have drag high enough to keep it from orbit. The work he described was done by Cohen (spelling?). 3) Laser launching system. He worked on this at Avco Everett. You use a laser to heat a gas to whatever temperature you require and shoot it out the back. Presumably, the laser would be on the ground shooting at the capsule going into orbit (See J. Pournelle's High Justice for a good sf story based on this idea.) You'd need about a gigawatt of power to launch one ton into orbit. A fair amount of research was done on this concept. Dr. Kantrowitz demonstrated a small version of this system to von Braun. His reaction was one of interest, but he asked that it not be publicized as the enemies of the shuttle would then have a weapon to kill the shuttle off without having something better to replace it. But what will really make people go into space? Pressures from society. The threat of nuclear war, limits to growth. He suggested that if pessimistic and optimistic visionaries would talk to each other rather than past each other, space is the obvious solution to many of our problems. After the talk, there was some discussion. One of the interesting points he made was that the space based, laser ballistic defense system looked very good to him. He was upset at Tsipis for his article in the December Scientific American because he left out possibilities that destroy the arguments he presented in the article. In particular, the power for such a system could also come from the ground via a mirror in higher orbit, or a larger nuclear power plant. He felt that such a large station could be easily shielded from the attack of another such large station (by mass), yet it would still be effective against missiles which have a thin shell. I found the talk fascinating. In particular, I was struck by the idea that the laser launching system could probably be developed at roughly the same cost as the shuttle. We blew it with the shuttle in a sense. For the same price we could have been putting pounds into orbit for at least a tenth the cost we'll be paying for the next decade. Bob Bruccoleri ------------------------------ Date: 8 Dec 1981 12:30:50-EST From: csin!cjh at CCA-UNIX To: Lynn.ES at PARC-MAXC Subject: getting there (high power) Cc: space at mit-mc Do you really believe that nuclear or electric power will be feasible for earth launches any time in the forseeable future? Most of the schemas I've seen for [electric] (e.g., ion-powered) rockets talk about low levels of continuous thrust, suitable for interplanetary travel. Note that you still have to have reaction mass from somewhere (although I suppose you could get as much as 20 miles up using ambient air as a reaction mass, which would help). I'm willing to look at long shots to get into space, but not to plan on miracles when proejcting what space will be like. ------------------------------ Date: 9 Dec 1981 0014-EST From: J. Noel Chiappa Subject: Galileo cut To: space at MIT-MC cc: JNC at MIT-XX 'Galileo Juptier orbiter/probe and 50% of NASA's aeronautics program have been cut from the agency's Fiscal 1983 budget by the OMB. The $300 million already invested in Galileo would be lost as well as about 1,200 jobs at the JPL. the move would end U.S. planetary exploration, a concept the White House supports. Aeronautics cuts would have a long term impact on national aeronautical capability, especially in competing with other world markets, and NASA administrator Beggs is expected to appeal directly to Reagan. White House OSTP, headed by presidential science advisor George Keyworth, has taken a position that the U.S. planetary program should be halted because of what the staff believes is limited 'show-biz' results compared with other scientific investigations.' There's more, specifically an article about the the House/Senate conference on the NASA budget, in which the legislature seemed pretty pro-NASA. The had money for a continuing option on two spacecraft for the ISPM, Galileo, aero research, orbiting infrared telescope, and (if I read this right) some for a fifth orbiter. An attempt to add Halley's lost. How many B-1's does it take to suppport a civilian U.S. space program? (Hint: same number as average administration member's IQ.) ------- ------------------------------ End of SPACE Digest ******************* ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.