Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Wed, 3 Apr 91 02:05:22 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 3 Apr 91 02:05:18 -0500 (EST) Subject: SPACE Digest V13 #349 SPACE Digest Volume 13 : Issue 349 Today's Topics: One Small Step for a Space Activist... Vol 2 No 4 Self Unloading Lunar Transport Vehicle Re: Let's build Freedom on the Moon Re: Solar Eclipse Re: Solar Eclipse Re: SPACE Digest V13 #344 Re: One Small Step for a Space Activist... Vol 2 No 4 Re: Solar Eclipse Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: Tue, 2 Apr 91 09:16:12 -0500 From: "Allen W. Sherzer" Subject: One Small Step for a Space Activist... Vol 2 No 4 One Small Step for a Space Activist... by Allen Sherzer & Tim Kyger In Search of Ancient Engines One interesting old myth about the space program is what happened to the Saturn V. Some say the parts and plans were lost; others say they were deliberately destroyed to protect Shuttle. Congress has recently been holding hearings on the NASA budget and interesting things are coming to light. Rocketdyne put together a presentation to brief the Synthesis Group on what it would take to build F-1s again (the F-1 was the first stage engine for the Saturn V). It turns out that all required plans and drawings exist and that several flyable engines still exist in environmentally controlled storage. Sources say that for about $100 million in startup costs a 58 engine lot could be built, with an average cost of $12.7M each, in 4.5 years. These engines would be rated at 1.8M pounds of thrust (compared to 1.5M for the Apollo-era engines), they would be throttable, and perhaps even be restartable. ALS on the other hand wants to build the Space Transportation Main Engine (STME). This engine will cost $2-3 BILLION to develop, and will cost about $5M a copy; its designed to produce 600,000 pounds of thrust. (Keeping the STME program going is Senator Howell Heflin's (D-AL) highest legislative priority this year). These new F-1s will cost 15% less per copy to build (measured by $$ per pound of thrust) and have 5% of the development costs of STME. NASA wants a heavy lift vehicle, guess which engine NASA is going to build? Legislative Roundup Spaceport Financing Act HR-1358, the Spaceport Financing Act, was recently introduced by Reps Bacchus (D-FL) and Shaw (R-FL). This bill will extend to spaceport bonds the tax status currently enjoyed by airport bonds. This is similar (but not as far reaching) as the equivalent provisions in last years Omnibus Space Commercialization bill of Rep. Bob Walker (R-PA). The bill has been referred to the House Ways and Means Committee for action. Things to do: 1. Write your Congresscritters and ask for support of this bill. This is especially important if your Representative is on Ways and Means. SSX As we reported recently, SDIO is working on several SSX-like launcher concepts. Of the four submitted two are vertical launch and landing, one is horizontal launch and landing, and another is vertical launch horizontal landing. These vehicles can be ready for launch in five years and will launch Atlas class payloads for 1/10 the cost of an Atlas. The budget for this project has been cut for next year. This means that it is likely that only one instead of two alternatives will be funded and that suborbital testing will slip by a year. SEI Some members of the House Space Subcommittee are beginning to object to the open-ended funding and schedule for SEI. They would like to see real schedules and budgets. We can help make this happen by writing our Congresscritters and encouraging them to demand that they be given real schedules and plans. (SEI is in last place behind Mission to Planet Earth, SS Freedom, and ALS in the funding battles). Synthesis Group Expect to see Stafford's Synthesis Group report issued around May 1. Published reports say they will recommend four options for Mars. One is a direct trip; the other three build a Lunar base first. This report will be a good focus point for activists. Get a copy of the report and read it; it's important. One important aspect of the report is an emphasis on nuclear propulsion. All four options require it and as we reported last month DoE has money in next year's budget for it. So far so good, but activists will have an important role to play when the effort is ramped up. Eventually the antinuclear people will get wind of this and raise hell. Activists did a good job dealing with this over the RTG issue and we will need to do it again. If you see a letter opposing space-based nuclear power in your local paper, write a reply. If we respond vigorously early on with reason and not hype, we can favorably shape the discourse. The Great Exploration Many of the technologies needed for SEI are being worked on by DoE. This will This will make it easier to get Great Exploration technologies (low cost launchers and inflatables) into SEI, which could reduce cost and schedule. Expect to see a lot of SEI funding inside DoE in the near future. Despite this, the Appropriations Committees will be reluctant to fund civil space with DoE funds (despite the fact that DoE is a member of the Space Council). The showdown will happen in a few months. Grassroots help will be needed to show support. Things to do: 1. MEET with your Representative and Senators. Ask them to write a letter to Rep. Bevil (D-AL) and Senator Johnston (D-LA) supporting this new program. 2. If you talk with your Senator about DoE efforts in civil space please don't give the impression that this effort will hurt NASA. NASA's support in the Senate is very strong. In fact, when supporters of commercial space legislation last year told senators that the legislation would get NASA out of the launch business, it made it a lot harder to get the bill passed. Instead tell them that DoE involvement will help leverage NASA's efforts (which it will) and that this effort is in line with the Augustine recommendations. Omnibus Space Commercialization Act The Omnibus Act is still pending and it may or may not have been 'dropped in the hopper' by the time you read this. This bill promises to enact into law many good ideas; get ready to push for it. Tidbits Sources inside General Dynamics say GD's internal management has killed their SDIO SSTO (SSX) effort... Word in the street in DC is that NASA should expect a $1 billion cut in the 92 appropriation... Allen Sherzer: (313) 769-4108 (W) (313) 973-0941 (H) aws@iti.org (net) Tim Kyger: (202) 225-2415 (W) (703) 548-1664 (H) (800) 673-1762 (voice mail) p Allen ------------------------------ Date: 2 Apr 91 19:08:50 GMT From: ccncsu!longs.LANCE.ColoState.EDU!jn190068@purdue.edu (Jay Nestle) Subject: Self Unloading Lunar Transport Vehicle I am currently designing a self unloading reusable transport vehicle and wanted to throw my ideas at the space readers for responses. Please email me. My vehicle is designated L-SURV for lunar self unloading reusable vehicle. Basically this vehicle would operate from LLO to lunar surface and back. This would assume a transfer platform of some kind in lunar orbit and reliable OTVs. Would a design of making the L-SURV capable of OTV between LLO and LEO be more practical? Basically this means adding an aerobrake and more fuel for the round trip. The self unloading is going to be done with cabling holding the payload (station derived modules or cargo pallets) that will be severed or disconnected with exploding bolts. Does anyone know where explosive bolt information can be obtained? Also has anything like this been done in the past? Especially in space. The propulsion will be attached to the sides of the vehicle, this is so the payload can be "dropped off" the bottom. This is structurally more complex but with the added simplicity of unloading we felt this was the best. Please feel free to discuss these proposed ideas and keep me informed on what you all think! Thanks! Jay Nestle jn190068@longs.lance.colostate.edu "Save the earth, develop space." - Bumper Sticker ------------------------------ Date: 3 Apr 91 01:03:49 GMT From: hub.ucsb.edu!ucsbuxa!3001crad@ucsd.edu (Charles Frank Radley) Subject: Re: Let's build Freedom on the Moon The NASA 90 day study proposed exactly that .. a lunar base composed initially of Freedom modules. ------------------------------ Date: 3 Apr 91 02:25:46 GMT From: phoenix!winnie@princeton.edu (Jon Edelson) Subject: Re: Solar Eclipse In article <9104030026.AA27105@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >So for eclipses, I imagine it would be a slightly lesser degree of the same >risk. Viewing the sun even during a partial eclipse is never recommended >unless you know what you're doing and use a projection system or a filter >approved for your particular application. Watch out for this one, some years ago there was an eclipse in my home town, and on the news was info about viewing. One of the things mentioned was that if you are not careful to use the proper filter, the visible intensity of the light would be reduced to the point where you could (comfortably) look directly at the sun, yet the level of IR or UV would be high enough to cause damage. Maybe John could post his projector design. -Jon Edelson (winnie@pucc.princeton.edu) ------------------------------ Date: 2 Apr 91 09:55:54 GMT From: elroy.jpl.nasa.gov!sdd.hp.com!wuarchive!waikato.ac.nz!aukuni.ac.nz!groc1@lll-winken.llnl.gov (GuyonAlanEdward Roche ) Subject: Re: Solar Eclipse In <31530@usc> robiner@mizar.usc.edu (Steve Robiner) writes: >Can someone out there who has seen (well, maybe not directly) a total >solar eclispe describe to me what it and the sky look like at the time? >Questions: >Does the whole sky turn very dark (or just a circular area around the >sun/moon? Can one see the stars in that area? Not actually sure on this one, but I think the whole sky goes dark. >Is it truly more dangerous to look at an eclipse than looking at the >normal sun? It can't possibly be any brighter. The only danger I can >see is that while viewing the relatively dark eclipsed sun, the moon >moves out of the way, and one's dialated eye is caught off gaurd and >exposed to the sun's full brightness. Is there any other danger >beyond that? As I understand it, though the sun might not look very bright during a total eclipse, the intensities at non visible wavelengths ( infra-red ) are, and it is very easy to cause much damage to the retina without knowing >Has the sun's corona been observed above the Earth's atmosphere? If not, >isn't possible that it is merely an atmospheric phenomenon, just light >scatering and refracting around the edges of the moon. No the Corona is a real part of the sun caused by light emitted and reflected by particles that are continuously streaming away from the sun. (refracting around the sun ? HOW?) >How big is the Moon's shadow on the Earth? I would guess it's nearly the >size of the moon, but there must be some refraction of light around the >edges of the moon, making the totally dark shadow of the moon somewhat >smaller. The Umbra of the shadow (the bit that sees no sunlight) is sometimes quite large and sometimes isn't there at all (see annular eclipse) >Is the moon, during a full total eclipse, exactly the same apparent size as >the sun, or is it larger? the orbit of the moon is not circular it is ecliptic, which means sometimes it may seem larger (when it is close to the Earth) and other times it may seem smaller(when it is farther away). Hope this is of some assistance /-------------\ | Guyon Roche | \-------------/ -- New administrater uofa. ------------------------------ Date: Tue, 02 Apr 91 15:48:00 EST From: Tom McWilliams <18084TM@msu.edu> Subject: Re: SPACE Digest V13 #344 Re; Railguns, EM launchers No one has given a good explanation of how to beat the frictional problems of a PURE gun-style launcher. No matter how aerodynamic you make it, friction won't come down below roughly .25 This is not ablative friction, but just skin-adhesion friction (I can't remember the right term). Even if you make 'real long and thin', you'll just raise your coefficient, since you've raised the surface area. Since friction only becomes a real problem at high sppeds, consider this idea for the application of gun-type launchers: Use a short rail, with moderate acceleration to put a fully-loaded, already- been-tested-and-budget-approved chemical rocket moving up at around, say, 300mph, then fire the rockets. Remeber the Saturn V? It put about 200,000lbs into LEO. It also burned about 1 ton of fuel PER SECOND as it was leaving the pad. If it takes, say 20 s to get up to 300mph, a partial rail-gun system could save 10 tons, or about 20%. 400mph could save, roughly, 35%, etc. Now, combine that with the HOTOL concept, saving all the wieght of the O2, the haviest part of the fuel anyway, for a payload savings around, say, 90%. And that's not even talkin' 'bout the vechicle itself, or possible reusability. I'm just an armchair aerospace engineer, after all. Could you handle the acceleration up to 400mph over, say 5mi? Could you afford the easments?, etc. I think so. R&D? The rockets we have. HOTOL is really just a plane with o2 systems. Railguns are converted roller coasters. Of course there's more to it than I make it sound, but there is far less invloved than when you start from scratch, with say, laser or nuclear. The fact that I can think of this, yet find no reference of the combination of similar technologies to yeild better launch efficiencies elsewhere, is my proof that the chemical rocket is not streched to it's limits, or fully explored. BTW: That's a ditto for EM, Rail, Hotol, Reusability, etc. P.S> I think chemical rockets will never, ever, have a market outside of LEO. My personal favorites are the ion rocket and solar sail. Tommy Mac I sure hope I get to see if I'm right! 18084tm@msu Acknowledge-To: <18084TM@MSU> ------------------------------ Date: 3 Apr 91 01:06:02 GMT From: hub.ucsb.edu!ucsbuxa!3001crad@ucsd.edu (Charles Frank Radley) Subject: Re: One Small Step for a Space Activist... Vol 2 No 4 I am puzzled about complaints that nobody is proposing "real" hardware and schedules for SEI. The following paragraph answers the question - everybody has been holding off waiting for the synthesis report....... ------------------------------ Date: 2 Apr 91 20:07:35 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jarthur!nntp-server.caltech.edu!palmer@ucsd.edu (David Palmer) Subject: Re: Solar Eclipse tholen@uhccux.uhcc.Hawaii.Edu (David Tholen) writes: >An eclipsed Sun is no more dangerous to look at than a normal Sun. The added >danger simply stems from the fact that people have a reason to look at the >Sun during an eclipse, but not at other times. Having said that, let me >emphasize that both a normal Sun and an eclipsed Sun are indeed dangerous >to look at directly. Don't do it, if you value your eyesight. WRONG. When the sun is only a little way out from behind the moon, your eyes tend to be fully dilated. This allows 50 times as much light per in as before. Although the sun, when 98% covered, has fifty times less light coming from it, this means that the same amount of light hits your retina. However, the light, instead of falling in a 1/2 degree circle, is compressed in a thin cresent. This gives you fifty times the light per unit area on your retina. So in one second, that area gets as much heat as you would get by staring at the sun, without moving your eyes, for about a minute. It is, of course, much worse when all that heat comes at once. A lot of people have crescent-shaped burns on their retinas from this. -- David Palmer palmer@gap.cco.caltech.edu ...rutgers!cit-vax!gap.cco.caltech.edu!palmer "Operator, get me the number for 911" --Homer Simpson ------------------------------ End of SPACE Digest V13 #349 *******************