Date: Tue, 8 Dec 92 05:06:00 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #521 To: Space Digest Readers Precedence: bulk Space Digest Tue, 8 Dec 92 Volume 15 : Issue 521 Today's Topics: anniversary Liquid Hydrogen Price lunar flight Orbit Question? Potential uses for the DC-X Science use of the Sr-71 Shuttle Replacement/Shuttle Costs US/Sov space comparisons Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "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: 7 Dec 92 22:23:45 GMT From: carlosn@luma.Princeton.EDU.ampr.org Subject: anniversary Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: > Lest we forget... Twenty years ago today -- to be precise, at 0033 EST -- > the last ship left for the Moon. > -- > "God willing... we shall return." | Henry Spencer @ U of Toronto > -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry ... And to think that some of us were only months old when that happened. And we will be very lucky if we see it happen again before we reach our forties. :( The little Cernan quote kind of got to me. -- --------------------------------------------------------------------- | Carlos G. Niederstrasser | It is difficult to say what | | Princeton Planetary Society | is impossible; for the dream of | | | yesterday, is the hope of today | | | and the reality of tomorrow | | carlosn@phoenix.princeton.edu |---------------------------------| | space@phoenix.princeton.edu | Ad Astra per Ardua Nostra | --------------------------------------------------------------------- -- --------------------------------------------------------------------- | Carlos G. Niederstrasser | It is difficult to say what | | Princeton Planetary Society | is impossible; for the dream of | | | yesterday, is the hope of today | ------------------------------ Date: Mon, 7 Dec 1992 23:47:57 GMT From: Paul Dietz Subject: Liquid Hydrogen Price Newsgroups: sci.space In article <18235@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes: > For comparison, the book Shuttle lists the following prices of other >propellants: ... >N2O4 $33.00 per gallon > > Whatever the price of hydrogen is, it looks good relative to other >propellants. Probably the only thing cheaper on the fuel side would be RP-1 >or another hydrocarbon, or ammonia (which isn't used in any current engines). I am quite surprised by this price. Nitrogen dioxide is made in large quantities in nitric acid synthesis plants (from catalytic oxidation of ammonia). I would have thought that tapping some of it off and compressing would provide a ready source of nitrogen tetroxide. Or is that source too contaminated with nitric oxide? Perhaps the problem is just one of low demand, or unusual purity demanded by NASA. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 7 Dec 92 22:14:03 GMT From: carlosn@luma.Princeton.EDU.ampr.org Subject: lunar flight Newsgroups: sci.space In article <1992Dec7.060331.10793@ringer.cs.utsa.edu> sbooth@lonestar.utsa.edu (Simon E. Booth) writes: > In article roberts@cmr.ncsl.nist.gov (John Roberts) writes: > > > >-From: henry@zoo.toronto.edu (Henry Spencer) > >-Subject: Re: Lunar flight > >-Date: 6 Dec 92 01:49:57 GMT > >-Organization: U of Toronto Zoology > > > >-Except that Clinton & Co have already came out as opposed to any resumption > >-of manned space exploration, or any preliminary steps towards it, no matter > >-how cheap. > > > >Wrong. > > > I second that. I truly hope our space program can survive the Clinton > administration. Based on info I read during the campaign VP-elect Gore > is very pro technology. While I didn't vote for Clinton/Gore, I won't > write off our space program yet. Simon I would disagree. Gore is very pro 'environmental' technology so yes EOS will be alive. But read their policy statement regarding space (posted here before the election) *Biggest focus- Mission to planet Earth *The only reason they mention to keep Freedom is because it creates jobs. Whether you think Freedom will or will not generate good science, keeping it only for the jobs is a lousy way to run a space program. *Moon, Mars, and the Space Exploration Initiative, are mentioned as worthy goals... when we have the money. In other words not for a long, long time. I seriously think that for all his technology talk, the space program will be hurt under Clinton. Especially if, as has happened, in the fact it gets linked to defese simply because they both use Aerospace. -- --------------------------------------------------------------------- | Carlos G. Niederstrasser | It is difficult to say what | | Princeton Planetary Society | is impossible; for the dream of | | | yesterday, is the hope of today | | | and the reality of tomorrow | | carlosn@phoenix.princeton.edu |---------------------------------| | space@phoenix.princeton.edu | Ad Astra per Ardua Nostra | --------------------------------------------------------------------- -- --------------------------------------------------------------------- | Carlos G. Niederstrasser | It is difficult to say what | | Princeton Planetary Society | is impossible; for the dream of | | | yesterday, is the hope of today | ------------------------------ Date: Tue, 8 Dec 1992 00:07:13 GMT From: Pat Subject: Orbit Question? Newsgroups: sci.space In article David.Anderman@ofa123.fidonet.org writes: >Your polar geosyncronous satellite takes out one equatorial geosynchronous >satellite every 24 hours as it passes over the equator at 24,000 miles >altitude..... > >--- Maximus 2.00 A the odds of collision are low. big space, small satellite theory. also, you can really avoid the collision by putting giant fuel tanks on it, and essentially hovering over the poles. it's theoretical if ridiculous. ------------------------------ Date: Tue, 8 Dec 1992 00:22:35 GMT From: Pat Subject: Potential uses for the DC-X Newsgroups: sci.space So we are spending the money to build the DC-X and flight test it. are there any useful science missions it could conduct while up there? I would guess that while jets and balloons can fly higher and stay longer, only helicopters can conduct precision hovering, and they stay below 10,000 feet. Would there be an air sampling or astronomical observations that would want to hover around at 30,000 feet? I am certain i could conduct some great photographs, but would the DC-X be useful for like aerial photometry, or resource mapping? the U-2 has turned out to have some great research potential, maybe the DC-X or Y could also. ------------------------------ Date: Tue, 8 Dec 1992 00:26:03 GMT From: Pat Subject: Science use of the Sr-71 Newsgroups: sci.space Has NASA or NOAA or some other group looked at using the Sr-71 for science missions? or does it lack any advantage over the U-2s. i am sure it is much more expensive to operate then the U-2, but i am not sure if it has any real advantage other then speed. Thanks. ------------------------------ Date: Mon, 7 Dec 1992 20:05:22 GMT From: Edmund Hack Subject: Shuttle Replacement/Shuttle Costs Newsgroups: sci.space In article Wales.Larrison@ofa123.fidonet.org writes: [much good, solid assemblage of facts deleted - thanks Wales!] > [I should note that I have not included either an amortization of >sunk development costs, nor any Pre-planned Product Improvement >(P^3I) Program -- such as the ASRM or ASA. It should also be >noted, that with any other comparative system, that such >improvements and or amortization must be added to their costs, in a >fair one-to-one comparison.] Note that a lot of the SSTO supporters are treating their R&D costs as well as the site prep costs as sunk costs and not charging them against the ops costs. (This is from a set of SSX viewgraphs I read as well as some copies of the spaceflight journal that the High Frontier group in DC puts out). This is not uncommon in DOD accounting for weaposn systems costing. The cost of R&D and initial tooling is charged against the first unit out the assembly line. After that, the "Flyaway cost" is what is looked at. From a commerical accounting view,this is bogus, but from a year-to-year appropriations point of view, it makes a twisted kind of sense. >In that light, I support the DC-X program, >and the dem/val program for the SSTO Phase 1 program. They'll >answer SOME of the questions that are clouding the issue. So do I. Allen and I differ on who should develop and manage DC-Y - I favor Griffin's office of Exploration combined with Ames/Dryden. However, what is important is that it get done. It is unfortunate that the prime contractor is in such bad financial shape. >I also >support development of a NASP vehicle to answer a different set of >questions, and the demonstration of sea-launched and large pressure- >fed engines as well. NASA needs to get back into development mode and away from a lot of the silliness of the past. Goldin seems to be trying to turn the boat in that direction. -- Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah.. "You know, I think we're all Bozos on this bus." "Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode" ------------------------------ Date: 8 Dec 92 01:16:31 GMT From: Josh 'K' Hopkins Subject: US/Sov space comparisons Newsgroups: sci.space >henry@zoo.toronto.edu (Henry Spencer) writes: >>As for Apollo... the Soviets came within a hairsbreadth of sending cosmonauts >>around the Moon before Apollo 8, and last I heard, it's still not clear why >>they didn't -- the hardware was ready. They were behind on the capability >>to make an actual lunar landing, but not that far behind. I wrote: >\When I see something I think is stupid I usually tell myself that either the >/other person is insane or they know much more than I do. My first reaction >\to this was the former, but when I saw who wrote it I decided to assume the >/latter. I was under the impression that the Soviets were still blowing up >\N-1s well into the seventies. What am I missing? And Phil responded with a good summary of the Zond program. I was aware of the Zond program, though I hadn't realized it had gone quite that far. What I was specifically responding to was the comment that they were "not that far behind" in the capability to land on the surface. Maybe it's just a matter of what one considers "not that far." I personally consider the Soviet lunar landing program a complete failure and I was just wondering whether Henry had different data then I did. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu Ho^3 !=L ------------------------------ End of Space Digest Volume 15 : Issue 521 ------------------------------