Date: Fri, 17 Jul 92 05:01:50 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #008 To: Space Digest Readers Precedence: bulk Space Digest Fri, 17 Jul 92 Volume 15 : Issue 008 Today's Topics: ACRV study contract terminated. Another vote on DCX - help needed. apollo 10 First image of sun in neutrons [Release 92-113] (Forwarded) FTL drives (3 msgs) Interplanetary communications relays Need Testers for MS Windows Astronomy Program Propulsion questions (5 msgs) Shuttle tires Solar Power Satellites Space Transportation Infrastructure Costs (Was Re: Interstates) (3 msgs) Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu" (on Internet). If you are on Bitnet, you must use a gateway (e.g., "space%isu.isunet.edu@CUNYVM"). Please do **NOT** send (un)subscription requests to that address! Instead, send the message "Subscribe Space " to one of these addresses: listserv@uga (BITNET), RICE::BOYLE (SPAN/NSInet), UTADNX::UTSPAN::RICE::BOYLE (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 16 Jul 92 17:08:01 GMT From: Edmund Hack Subject: ACRV study contract terminated. Newsgroups: sci.space I just heard today that NASA is terminating the Phase B study contracts for the ACRV. One contract is held by LMSC, the other(s) I am not sure of. I guess that the Soyuz deal may be farther along than anyone thought. -- | Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX | hack@aio.jsc.nasa.gov SpokesPersonp(Me,or(NASA,LESC)) = NIL | **** Papoon for President! You Know He's Not Insane!! **** ------------------------------ Date: Thu, 16 Jul 1992 20:35:23 GMT From: "Allen W. Sherzer" Subject: Another vote on DCX - help needed. Newsgroups: sci.space,talk.politics.space The following memo was written by Tim Kyger of Rep. Rohrabacker's (R-CA) office. They have been taking the lead in keeping SSRT alive. Another important vote is coming up and help is needed. Allen ----------------------------------------------------------- Memorandum To: DC-X Proponents From: Tim Kyger Subject: DC-X -- What Should Now Be Done Thursday, July 16th, 1992 1. The House Appropriations Committee ("HAC") and its Defense Subcommittee Chair, Representative John Murtha, will take the position in conference with the Senate on the FY '93 Defense Appropriations Bill (H.R. 5504) that SSRT funding should be restored (said conference occurring probably sometime in early September). Nevertheless, the prejudicial language terminating SSRT contained in the HAC's Committee Report H. Rpt. 102-627 has passed into the outside world, and the same arguments against SSRT as are presented and justified in H. Rpt. 102-627 are butrussed by their presence in that report. 2. We must assure that there is as much positive support from Congress for SSRT as is possible before the HAC/SAC ("Senate Appropriations Committee") conference on the Defense Appropriations Bill. This will help to neutralize the language of H. Rpt. 102-627. 3. Favorable SSRT language should therefore, if possible, be a part of the SASC's Committee Report on their FY '93 Defense Authorization Bill ("Senate Armed Services Committee" -- "SASC"). 4. The order will be SASC first, SAC second. SASC will mark up this coming week, but SAC and its Defense Subcommittee will not be marking up until sometime in August. Furthermore, friends of SSRT/SSTO are members of the SAC; they will no doubt be willing to help in the days ahead to convince their colleagues to include favorable SSRT language in their Committee Report from the start (yet another means to help neutralize the caustic effects of the House Report's SSRT language"). In other words, we have time to work the SAC to prepare them to be favorable in conference with Mr. Murtha. 5. The SASC's Subcommittee on Defense Industry and Technology ("SASC DI&T"), chaired by Senator Jeff Bingaman of NM, will meet on Monday, July 20th at 2pm to mark-up their bill. This means report language on SSRT should be a part of that mark-up. This also means, frankly, that Mr. Bingaman must be "gotten to" in the next two days or so. 6. Letters, phone calls, faxes, etc., should be made to Senator Bingaman's office asking that the SSRT DC-X ATD program be supported in the SASC's Committee Report. The more and varied the positive contacts supporting SSRT that Senator Bingaman receives, the better. 7. Following are the names, addresses, phone and fax numbers of the Senators on the SASC DI&T Subcommittee; you could also be calling/faxing/writing them: Senator Jeff Bingaman (Chair of SASC/DI&T) (D-NM) SH-524 U.S. Senate Washington, D.C. 20510-3102 202/224-5521 Fax: 202/224-1810 Senator Al Gore (D-TN) SR-393 U.S. Senate Washington, D.C. 20510-4202 202/224-4944 Fax: 202/224-0580 Senator Tim Wirth (D-CO) SR-380 U.S. Senate Washington, D.C. 20510-5852 202/224-5852 Fax: 202/224-1933 Senator Robert Byrd (D-WV) SH-311 U.S. Senate Washington, D.C. 20510-4801 202/224-3954 Fax: 202/224-4025 Senator Dan Coats (R-IN) SR-407 U.S. Senate Washington, D.C. 20510-1403 202/224-5623 Fax: 202/224-1966 Senator Connie Mack (R-FL) SH-517 U.S. Senate Washington, D.C. 20510-0904 202/224-5274 Fax: 202/224-8022 Senator Bob Smith (R-NH) SD-322 U.S. Senate Washington, D.C. 20510-2903 202/224-2841 Fax: 202/224-1353 [it is most effective if you call the Senator's office and ask to speak with the staffer responsible for defense issues. Tell them about the program and ask the Senator to support it. Also, I will post results when I get them. -Allen] -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "If they can put a man on the Moon, why can't they | | aws@iti.org | put a man on the Moon?" | +----------------------281 DAYS TO FIRST FLIGHT OF DCX----------------------+ ------------------------------ Date: 16 Jul 92 16:50:13 GMT From: Charles Frank Radley <3001crad@ucsbuxa.ucsb.edu> Subject: apollo 10 Newsgroups: sci.space Objects in low lunar orbit tend to "decay" because of "Mascons" or Mass Concentrations, which locally increase the gravitational field, and disturb the satellite's orbit. The Moon cannot be treated as a point object for this reason, so simple elliptical orbital equations do not apply to objects orbiting the Moon. Nobody seems certain of the origin of "Mascons", they might be massive buried meteorites. ------------------------------ Date: Thu, 16 Jul 1992 20:06:39 GMT From: Roland Karlsson Subject: First image of sun in neutrons [Release 92-113] (Forwarded) Newsgroups: sci.space How was it made? I surely want some description of the method. -- Roland Karlsson SICS, PO Box 1263, S-164 28 KISTA, SWEDEN Internet: roland@sics.se Tel: +46 8 752 15 40 Fax: +46 8 751 72 30 Telex: 812 6154 7011 SICS Ttx: 2401-812 6154 7011=SICS ------------------------------ Date: Thu, 16 Jul 1992 18:01:05 GMT From: "Thomas J. Nugent" Subject: FTL drives Newsgroups: sci.space derek.wee@f820.n680.z3.fido.zeta.org.au (Derek Wee) writes: > Just out of interest, I'm compiling a list of the FTL drives used in >science fiction stories and computer games. I have already got: [stuff deleted] > The method used in `Lensman' series also baffles me, having something to >do >with the element iron. I can't remember exactly, but in the 'Lensman' series, didn't they supposedly "nullify" inertia, so that any object automatically assumed a speed at which all forces on it balanced out? So out in space, with a relatively small push, you go so fast that you have drag from interstellar gas keeping you from moving at "infinite" speed. "I believe that there are moments in history when challenges occur of such a compelling nature that to miss them is to miss the whole meaning of an epoch. Space is such a challenge." - James A. Michener -- "To be average scares the hell out of me." -- Anonymous Tom Nugent e-mail: tjn32113@uxa.cso.uiuc.edu ------------------------------ Date: 16 Jul 92 17:55:04 GMT From: Shari L Brooks Subject: FTL drives Newsgroups: sci.space I never saw the original request, so am unsure if you have this...In Vonda McIntyre's _superluminal_, they traveled along hyperdimensional axes (the higher the dimension, the farther you went). This travel was incompatible with rhythms and pilots had to replace their hearts with mechanical, non- beating pumps. Also, in another McIntyre book, the ship uses a solar sail to get to a magnetic cosmic string, grabs the string with magnetic claws, rotates around it to end up elsewhere in the galaxy. -- Shari L Brooks | slb%suned1.nswses.navy.mil@nosc.mil NAVSOC code NSOC323D | shari@caspar.nosc.mil NAWS Pt Mugu, CA 93042-5013 | --> All statements/opinions above are mine and mine only, not the US Navy's. ------------------------------ Date: 16 Jul 92 21:03:13 GMT From: SCOTT I CHASE Subject: FTL drives Newsgroups: sci.space In article , derek.wee@f820.n680.z3.fido.zeta.org.au (Derek Wee) writes... > >Just out of interest, I'm compiling a list of the FTL drives used in >science fiction stories and computer games. I have already got: > In "Cascade Point," By Timothy Zahn (is that the right name?) the spacecraft uses a "Colloton drive" to enter a space which is a bilinear conformal mapping of normal space. (Circles map to lines, lines to circles.) You rotate the ship through a specified angle, and when you turn off the drive you are light years from your starting point. Of course, you had better not still be rotating as you turn off the drive and leave Colloton space, or your ship will be spread out over millions of miles! For reasons not entirely explained, while in Colloton space you also see multiple images of yourself, in a cross-like pattern with yourself in the center, where each image is a possible reality differing incrementally from all the others. You get to see what you might have been if only you had accepted that job, or married that girl, etc. -Scott -------------------- Scott I. Chase "The question seems to be of such a character SICHASE@CSA2.LBL.GOV that if I should come to life after my death and some mathematician were to tell me that it had been definitely settled, I think I would immediately drop dead again." - Vandiver ------------------------------ Date: Thu, 16 Jul 1992 16:58:36 GMT From: "Don M. Gibson" Subject: Interplanetary communications relays Newsgroups: sci.space gary@ke4zv.uucp (Gary Coffman) writes: >True, but I would like to belabor the obvious for just a while longer. >A relay at Jupiter orbit for a Saturn mission would still require a this assumes that jupiter and saturn are in conjunction. if they aren't, then it is *real* dumb to put a relay satellite around jupiter for a saturn mission. ------------------------------ Date: 16 Jul 92 21:31:24 GMT From: Tom Chapin Subject: Need Testers for MS Windows Astronomy Program Newsgroups: comp.windows.ms,comp.windows.ms.programmer,sci.astro,sci.space,sci.edu,comp.ibm.pc.misc ebergman@nyx.cs.du.edu (Eric Bergman-Terrell) writes: :*** Beta Testers Needed for Windows 3.X Astronomy Program *** : :Testers will send feedback via e-mail to ebergman@nyx.cs.du.edu. : :Eric Bergman-Terrell :ebergman@nyx.cs.du.edu Strange....my mail was returned "User unknown"... -- tom chapin tjc@hrccb.att.com (effective Aug 1, 1992: tjc@hrcce.att.com) ------------------------------ Date: P From: Rob Douglas Subject: Propulsion questions Newsgroups: sci.space Organization: Worcester Polytechnic Institute Date: Thu, 16 Jul 1992 15:46:32 GMT Lines: 29 Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU We were sitting around discussing this and not getting any where, so I decided to ask the experts. 1) If a space ship used a fusion reactor for propulsion, how would that work? Doesn't there have to be something sent out the back of the ship, so that the ship has to conserve momentum and move forward? If so, then the amount of forward acceleration is limited by the weight carried by the ship at the start, and there is no way to have a very long term propulsion source. 2) Does this problem also work for matter-antimatter propulsion systems? Do you need a significant mass of both to destroy in order to propel the ship forward? 3) How does a solar sail work, then? Are there any existing models of a solar sail which have been shown to work? 4) I am not sure, but the only method of propulsion I can see is by using conservation of momentum since there is nothing to push against. Is this incorrect? -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Rob Douglas | (508) 831-5006 | Computer Science Department ~ ~ rdouglas@cs.wpi.edu | AI Research Group | Worcester Polytechnic Institute ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __ /_/ _ / /\ _ _, / _ _ / \ (_) /_) /_/ (_) /_/ (_) / (_\ _\ (_) ------------------------------ Date: Thu, 16 Jul 1992 17:45:35 GMT From: Henry Spencer Subject: Propulsion questions Newsgroups: sci.space In article <1992Jul16.154632.15534@wpi.WPI.EDU> rdouglas@cs.wpi.edu (Rob Douglas) writes: >1) If a space ship used a fusion reactor for propulsion, how would that work? >Doesn't there have to be something sent out the back of the ship, so >that the ship has to conserve momentum and move forward? Barring some more esoteric possibilities, yes. The point of using something like fusion is that it lets you expel that mass at higher velocity, which means you need less of it. The obvious way to build a fusion rocket is to build your fusion reactor with a small leak in it, with a nozzle on the other side of the leak. The thrust will be low but exhaust velocity will be very high. >...[then] forward acceleration is limited by the weight carried by the ship >at the start, and there is no way to have a very long term propulsion source. This is phrased a bit confusingly, but I assume you mean "when it runs out of fuel, it stops generating thrust", which is true. This is true of *any* rocket. The question, really, is not how long the thrust lasts, but whether it gives you the velocity you want. You *can* try to build a Bussard ramjet, which scoops up the interstellar gas to use as fusion fuel. Trouble is, that gas is awfully thin, and it's hard to scoop up enough to be useful. Worse, it's almost entirely ordinary hydrogen, and it's extremely difficult to build a fusion reactor that will burn that stuff at any useful rate. >2) Does this problem also work for matter-antimatter propulsion systems? ... Same situation. Rockets are limited by the capacity of their tanks. Antimatter is energetic enough that this is not a big deal, mind you; limits on antimatter production are likely to be more significant. You can also build an antimatter-powered Bussard ramjet, which scoops interstellar gas for reaction mass but is powered by antimatter. You're still limited by the size of your antimatter tank, but it's better than an antimatter rocket and doesn't have the fusion-reactor problem. The design of the scoop is still problematic. >3) How does a solar sail work, then? Are there any existing models of a >solar sail which have been shown to work? Light has momentum. When it bounces off a reflector, it exerts a force on it. A damn small force. You need a huge surface area to get useful thrust, but at least you're not burning fuel to do it. Solar sails are the slow freight rather than the passenger express, but they should work well in the inner solar system. Nobody has flown a solar sail with useful thrust, but there is no doubt that the principle works. Light pressure is a significant issue for satellite attitude control, and has in fact been harnessed for attitude control at least once (Mariner 10). >4) I am not sure, but the only method of propulsion I can see is by using >conservation of momentum since there is nothing to push against. Is this >incorrect? So far as we know, conservation of momentum is non-negotiable. If you want to go in one direction, *something* has to go in the opposite direction. But it doesn't necessarily have to be something you haul with you, if you're clever enough to find something else -- space is not completely empty. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Thu, 16 Jul 1992 18:42:39 GMT From: "Thomas J. Nugent" Subject: Propulsion questions Newsgroups: sci.space rdouglas@cs.wpi.edu (Rob Douglas) writes: >We were sitting around discussing this and not getting any where, so I decided >to ask the experts. Well, I don't know if I'm an expert, but this is an area of strong interest, and I did give a well-received talk on these topics last week. >1) If a space ship used a fusion reactor for propulsion, how would that work? >Doesn't there have to be something sent out the back of the ship, so >that the ship has to conserve momentum and move forward? If so, then the >amount of forward acceleration is limited by the weight carried by the ship >at the start, and there is no way to have a very long term propulsion source. Just like in regular rockets, you need a nozzle to provide thrust to the rocket from the exhaust. What happens (or will happen) in a fusion rocket is as follows: you cause (by whatever means) fusile material to fuse; this releases alot of energy; you add (or already have sitting there) some propellant which picks up energy from the fusion reaction; then you deflect the expanding plasma (it's energetic enough to cause all your propellant to become a plasma) with an electromagnetic nozzle; and thru the nozzle, force is imparted to the ship. An electromagnetic nozzle is basically a superconducting ring (or rings) with a _large_ current flowing in it. Due to some conductive properties of plasma, it magnetic field formed by the superconducting ring 'deflects' the plast, imparting force to the ring which is attached to the ship. Neat, huh? >2) Does this problem also work for matter-antimatter propulsion systems? Do >you need a significant mass of both to destroy in order to propel the ship >forward? Yes. Actually, the original idea for antimatter rockets was to use light itself as exhaust, using electron-positron annihilation to produce gamma-rays. Only problem is, gamma-rays have this annoying tendency to penetrate most matter, and not reflect from it very well (which is what you want - to reflect the light out the back). Later, they thought about using proton-antiproton annihilation. p-pbar creates alot of pions, mostly charged, along with some gamma rays. Now you are alot like a fusion rocket - add stuff to give yourself more thrust, deflect it all with a EM nozzle, and voila! The pions don't decay (into gamma rays, I think) until they've moved downstream 10's of meters, by which time they are of no use to you. >3) How does a solar sail work, then? Are there any existing models of a solar >sail which have been shown to work? Solar sails work by reflecting sunlight. Einstein showed that light has momentum. If you reflect light, by conservation of momentum, whatever reflected it has picked up momentum. Solar sails can move both towards and away from the sun, by slowing themselves down or speeding up (which you do by deflecting the light in a certain direction). As for existing models, some solar sails have been built. A couple (of increasing size) have been built by the World Space Foundation (I think) to be used in the race to the Moon at the end of this year (or sometime next year). Japan and Europe are also competing in this. Also, back in the 60's the idea was actually proved (unintentionally I suspect) by some weather satellite/balloon which was in orbit but had some aluminized mylar balloon about 30 ft across. Can't remember what it was called, but supposedly light pressure affected the perigee of its orbit by some 500 km! >4) I am not sure, but the only method of propulsion I can see is by using >conservation of momentum since there is nothing to push against. Is this >incorrect? No, this is for the most part correct. I'm not sure if gravity assists count as cons. of momentum, or if cons. of energy is also the prime driver (although energy is always conserved - supposedly). "[The space program] can help counter the head-on collision with the environmental chaos we now face; spearhead technological, competitive, and political leadership; stimulate young minds to excellence; and forge cultural bonds between nations for the benefit of all humanity." - Leonard David -- "To be average scares the hell out of me." -- Anonymous Tom Nugent e-mail: tjn32113@uxa.cso.uiuc.edu ------------------------------ Date: Thu, 16 Jul 92 18:57:45 GMT From: Dave Jones Subject: Propulsion questions Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1992Jul16.154632.15534@wpi.WPI.EDU> rdouglas@cs.wpi.edu (Rob Douglas) writes: > >>2) Does this problem also work for matter-antimatter propulsion systems? ... > >Same situation. Rockets are limited by the capacity of their tanks. >Antimatter is energetic enough that this is not a big deal, mind you; >limits on antimatter production are likely to be more significant. > Robert L. Forward is optimistic about the possibilities. He has a single-stage to Mars design based on hydrogen as reaction mass and anti-hydrogen as energy source. The actual amount of anti-matter involved is miniscule by comparison with the amount of reaction mass - essentially it's a conventional rocket with a very high specific impulse and an energy source that introduces little or no extra mass. According to Forward's trend analysis, we're perhaps a couple of decades away from being able to produce anti-hydrogen in sufficient quantity. Prices of millions of dollars per gram sound daunting, but you don't need that much of it. Storage of the anti-hydrogen is possible: Forward described cryogenic techniques already simulated. There would be some annihilation at the surface of the anti-hydrogen, but not much. > >>3) How does a solar sail work, then? Are there any existing models of a >>solar sail which have been shown to work? > >Light has momentum. When it bounces off a reflector, it exerts a force >on it. A damn small force. You need a huge surface area to get useful >thrust, but at least you're not burning fuel to do it. Solar sails are >the slow freight rather than the passenger express, but they should work >well in the inner solar system. > Light bounces, but solar wind doesn't. You can get thrust from both, but solar wind thrust is strictly radial. You can tack against the light pressure. -- ||))) If you build it )))))))))))))))))))))))))))))| ||))) They will cancel it - Field of Dweebs. )))))))))))))))))))))))))))))| ||))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))| ||Dave Jones (dj@ekcolor.ssd.kodak.com) | Eastman Kodak Co. Rochester, NY | ------------------------------ Date: Thu, 16 Jul 1992 19:30:40 GMT From: Henry Spencer Subject: Propulsion questions Newsgroups: sci.space In article <1992Jul16.185745.2393@pixel.kodak.com> dj@ssd.kodak.com (Dave Jones) writes: >>Light has momentum. When it bounces off a reflector, it exerts a force >>on it. A damn small force... >> >Light bounces, but solar wind doesn't. You can get thrust from both, >but solar wind thrust is strictly radial. You can tack against the >light pressure. Actually, there's a radial component from light too, because you don't get perfect reflection. And in fact, at any given sail angle, your reflection thrust is made up of a tangential component that actually gets you somewhere and a radial component that essentially reduces the Sun's gravitational field somewhat. The tangential component is maximized at a sail angle of about 37 degrees. My recollection is that solar-wind thrust is essentially negligible compared to light thrust. The only scheme I know of that does anything useful with the solar wind is Zubrin's magsail, which is a different kettle of fish entirely. You can't really tack a solar sail in the normal sense, because solar gravity doesn't make a very good keel. What you can do is reduce your orbital velocity and then wait for the Sun's gravity to reel you in. You do a lot of waiting in solar sailing, actually... -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 15 Jul 92 13:06:11 GMT From: Peter Jarvis Subject: Shuttle tires Newsgroups: sci.space,sci.space.shuttle In article schumach@convex.com (Richard A. Schumacher) writes: > >Stupid question: why are the tires inflatables, rather than made of, >say, a closed-cell foam? Same as for cars. Pneumatic tires are lighter, more flexible and therefore easier to start rolling once they hit the runway. I don't think solid tires would survive the runway impact and come out round. Peter Jarvis.......... ------------------------------ Date: Thu, 16 Jul 1992 18:08:29 GMT From: "Thomas J. Nugent" Subject: Solar Power Satellites Newsgroups: sci.space ralph.buttigieg@f635.n713.z3.fido.zeta.org.au (Ralph Buttigieg) writes: > to make it worse. Most people will live on Earth for some time to come, > to have humanity denied the sight of the stars would be tragic. > ta Well, if you live anywhere near any half pint city, you are mostly denied the sight of the stars. I live in Urbana, with the local population on the order of 100,000. You have to go really far out of town to see more than a dozen stars or so. "I believe that there are moments in history when challenges occur of such a compelling nature that to miss them is to miss the whole meaning of an epoch. Space is such a challenge." - James A. Michener -- "To be average scares the hell out of me." -- Anonymous Tom Nugent e-mail: tjn32113@uxa.cso.uiuc.edu ------------------------------ Date: Thu, 16 Jul 92 16:08:23 GMT From: Doug Mohney Subject: Space Transportation Infrastructure Costs (Was Re: Interstates) Newsgroups: sci.space In article <143u6fINN6tf@agate.berkeley.edu>, gwh@soda.berkeley.edu (George William Herbert) writes: > > If NASA were willing to look past the Shuttle, it would realize >that it could redesign the station in 15klb chunks (ugh), develop the >DC SSTO concept, and fly Freedom in it for less than it'll cost to >fly it on Shuttle as is. > Anyone for shooting the Shuttle program office people >in the name of progress? 8-) > >-george william herbert Are you NUTS? Fly Russian! It's developed, it'll cut down on Shuttle flights for assembly, and help out people who need it. Previous signature chastized by Canadian Grad Student who flayed the United States as a bully from his bastion of free speech in Pittsburgh, PA. Yes, fact IS stranger that fiction. -- > SYSMGR@CADLAB.ENG.UMD.EDU < -- ------------------------------ Date: 16 Jul 92 16:08:49 GMT From: "Allen W. Sherzer" Subject: Space Transportation Infrastructure Costs (Was Re: Interstates) Newsgroups: sci.space In article <143u6fINN6tf@agate.berkeley.edu> gwh@soda.berkeley.edu (George William Herbert) writes: > If NASA were willing to look past the Shuttle, it would realize >that it could redesign the station in 15klb chunks (ugh), develop the >DC SSTO concept, and fly Freedom in it for less than it'll cost to >fly it on Shuttle as is. Or consider this idea I have been tossing about inside my head: 1. The Feds form a non-profit company and for five to ten years invest in it what they now spend on the Shuttle (about $5B/year). 2. The compnay invests the money in bonds with a target yeild of about 10%. (Could be a bit more or less). 3. The compnay uses the interest to buy water (or whatever) delivered to a useful orbit. They pay $1,000 per pound first come first served until the interest income for that year runs out. (if nobody buys then the money is re-invested and the market will be larger next year). In the first year they should be able to buy ~500,000 pounds of water and an additional 500,000 pounds per year after. 4. Any year where more than 80% of the available funds are spent the offering price of water to LEO will drop by 10%. 5. When the price drops to $250/pound or so the effort ramps down with other launch service users taking the slack. 6. When the company is no longer buying launch services, the company is liquidated and the principle returned to the government. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "If they can put a man on the Moon, why can't they | | aws@iti.org | put a man on the Moon?" | +----------------------281 DAYS TO FIRST FLIGHT OF DCX----------------------+ ------------------------------ Date: Thu, 16 Jul 1992 17:29:31 GMT From: Henry Spencer Subject: Space Transportation Infrastructure Costs (Was Re: Interstates) Newsgroups: sci.space In article <143u6fINN6tf@agate.berkeley.edu> gwh@soda.berkeley.edu (George William Herbert) writes: >>Most of the unmanned people are very thoroughly locked into the mindset >>of never depending on new technology if they can avoid it. (As witness >>Cassini being shrunk to fit on a Titan IV without the new SRBs... > > If NASA were willing to look past the Shuttle, it would realize >that it could redesign the station in 15klb chunks (ugh), develop the >DC SSTO concept, and fly Freedom in it for less than it'll cost to >fly it on Shuttle as is. Well, the real problem here (as with Cassini) is the attitude that one cannot depend on such things because they are too risky. It's a real issue, but it's been taken too far. (Depending on the shuttle is risky too, after all...) We've reached the point where everyone is so afraid of taking chances that very little progress is being made. Some of the new manned programs being proposed are at least being explicit that they will accept some degree of risk. -- There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry ------------------------------ End of Space Digest Volume 15 : Issue 008 ------------------------------