Date: Fri, 1 Jan 93 05:02:26 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #620 To: Space Digest Readers Precedence: bulk Space Digest Fri, 1 Jan 93 Volume 15 : Issue 620 Today's Topics: Aluminum as rocket fuel? fast-track failures Galileo's high-gain antenna still stuck Galileo antenna questions Government-run programs Was: Re: Justification for the Space Program (2 msgs) Justification for the Space Program (3 msgs) Moon Dust For Sale Public support for the space program (3 msgs) Sea floor Planetary Protection really. Space List Flame Wars SSTO vs 2 stage (2 msgs) 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: 31 Dec 92 20:09:09 GMT From: Bruce Dunn Subject: Aluminum as rocket fuel? Newsgroups: sci.space > Nick Janow writes: > Pumping is simple, since aluminum is highly conductive. Just use > electromagnetic fields to thrust it through a pipe. There's no moving > parts > to worry about. I think this is being used in sodium reactor research, so > it > isn't an untested technology. I think the fundamental problem with this is where to get the large amounts of power needed. Even moderate sized rocket engines use turbopumps generating several thousand kilowatts of power. Paul Deitz has pointed out in E-mail to me that molten aluminum would be an ideal candidate for pressure feeding. Relative to normal fuels such as hydrogen (density 70 kg/m^3) and RP-1 (density 800 kg/m^3), aluminum with a density of about 2700 kg/m^3 will require small tanks. The tanks are very hot, meaning that little mass of pressurization gas will be needed. A useful technique might be to have the molten aluminum stored in a spherical steel tank pressurized by injecting liquid nitrogen into the tank (which because of the heat will immediately vaporize). Is nitrogen available from the moon? -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ Date: 31 Dec 92 19:59:26 GMT From: "forrest.e.gehrke" Subject: fast-track failures Newsgroups: sci.space In article KitchenRN@ssd0.laafb.af.mil writes: >> >>Take what ever you are paying (~7%-9%, I forget exactly what) and add in >>an equal amount from your employer. Now kiss it goodbye, because anyone >>under 50 ain't gonna see it come back :-( 6.2% up to $55,500 in 1992 for Soc.Sec. and 1.45% up to $130,200 for Medicare from the employee and also from the employer. >And now we hear that the Clinton administration is proposing to push back the >retirement age so that they won't have to pay out so much Social Security. >If the trend continues, by the time I "retire", the retirement age will be >90! 90 may be somewhat pessimistic, but it *should* be raised. In 1935 when age 65 was chosen most retirees lived less than 3 years more, so Social Security didn't have to pay out very much. Now very many people live 20 years more and the system has some problems with that. For present retirees this system is a nice Ponzi scheme. But it obviously can't continue this way. (This thread doesn't belong here, but I couldn't resist responding). Forrest Gehrke feg@dodger.att.com ------------------------------ Date: Thu, 31 Dec 92 18:51:25 GMT From: Dave Jones Subject: Galileo's high-gain antenna still stuck Newsgroups: sci.space Marc N. Barrett (barrett@iastate.edu) wrote: > In article <1992Dec30.223543.23648@news.arc.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: > > Yesterday, December 29, after approximately 20 hours of > >warming in sunlight, the antenna-deploy motors were turned on to > >"wind up" the system and then pulsed to "hammer" it in an effort > >to free the stuck ribs of Galileo's high-gain antenna. The > >procedures began at 6:55 a.m. PST and continued until 2:48 a.m. > >PST this morning, December 30. A total of 2160 pulses were > >executed by the motors during this period. The stuck ribs were > >apparently not freed. This morning the spacecraft was returned > >from the warming attitude to the normal cruise mode. > > Well, what now? What else is being planned to free the antenna? And is > it expected to work? > According to the calendar released here recently, there are at least two more hammering episodes scheduled. After that it's plan B: use the LG antenna, data compression and other techniques to do as much of the mission as possible. -- ||------------------------------------------------------------------------ ||Dave Jones (dj@ekcolor.ssd.kodak.com)|Eastman Kodak Co. Rochester, NY | ------------------------------ Date: Thu, 31 Dec 1992 12:10:28 MST From: "Richard Schroeppel" Subject: Galileo antenna questions Ron Baalke has passed on the report that the Galileo antenna didn't open in response to repeated hammering on the deployment mechanism. My first question: Is the hammering at a constant frequency? Why not vary the frequency continuously in a "chirp", hoping to find a resonance that vibrates the whole antenna? If there are any springs in the ribs, there may be a resonance in the 1 second time range. My second question: During the quick-look playback of the first Gaspra pictures, shortly after the encounter, there was a lot of concern for wear on the tape-recorder rewind mechanism. Many rewinds were required to play back a few pictures. Is this still a concern? How will the Ida data playback be managed (at 10 baud), and the images from Jupiter & the moons? What will the data rate be from the vicinity of Jupiter? Rich Schroeppel rcs@cs.arizona.edu ------------------------------ Date: Thu, 31 Dec 92 14:10:24 EST From: Brad Porter Subject: Government-run programs Was: Re: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article neff@iaiowa.physics.uiowa.edu (John S. Neff) writes: >When JFK gave his speech in 1961 he talked about intangible benefits from >an effort to put AMERICANS on the moon. I don't recall that he said anything >about science and technology as a reasons for making the effort. There were >many benefits including scientific and technical ones from the Apollo >program. Was the money well spent? I think most people would say yes. > Well, we must keep in mind that the putting man on the moon was part of the "Space Race", and therefore greatly influenced by the Cold War attitudes. Modern critics may need better justification than national prestige. All-in-all, though, the nationalism that was/can be generated is an excellent reason to support the space program. Unfortunately, the rhetoric used by Kennedy won't really work anymore. >Today we have AMERICANS in space on an occasional basis, with the possibility >of more or less continuous presence of AMERICANS in space within the next >decade. Is this worth what it costs? If the majority of the people think >so we will keep on with this program, if not we won't. There is no such >thing as an inexpensive space program and in particular a manned space >program. If we worked hard at mundane things like industrial engieering >we might be able to reduce the cost of placing something in LEO by >perhaps 50%. That would be a good thing but it will not make it possible >for Joe Six Pack to vacation in space. Space IS a marketable industry in my opinion. -Brad Porter DRPORTER@SUVM Anything mentioned as an opinion is an opinion and does not necessarily have facts to support it. ------------------------------ Date: Thu, 31 Dec 1992 19:51:31 GMT From: "Dr. Norman J. LaFave" Subject: Government-run programs Was: Re: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec31.184656.14629@cs.rochester.edu> Paul Dietz, dietz@cs.rochester.edu writes: > Year Increase Same Reduce End No Opinion > 1984 21% 48 23 5 3 > 1986 26 50 14 5 5 > 1989 27 42 22 4 5 > 1990 17 37 32 10 4 Thank you Paul, I truly appreciate it. However, this just proves what I have believed for a long time. First, in response to questions like this people are going to list those items which effect their lives immediately first. Second, the average citizen has no understanding of the benefits derived from science R&D including space exploration and no real vision of the future (NASA has failed at public relations). Finally, note that they support manned over unmanned and they are for keeping funding the same (not ending it as you have suggested). I am bothered by the fact that nobody asked the question if funding should increase at the inflation rate. Norman Dr. Norman J. LaFave Senior Engineer Lockheed Engineering and Sciences Company When the going gets weird, the weird turn pro Hunter Thompson ------------------------------ Date: 31 Dec 92 18:40:19 GMT From: Patrick Chester Subject: Justification for the Space Program Newsgroups: sci.space,talk.politics.space In article <1992Dec29.011735.16300@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: ]In article <1992Dec28.223226.12849@aio.jsc.nasa.gov> Dr. Norman J. LaFave writes: ] ]> My arguement has the benefit of centuries of historical precedent ]> which is more than your "There will never be benefits worth the ]> expense" arguement you are spouting which can be ]> easily argued against using the same historical ]> information. Can I prove my assertion? ]> No. However, neither can you prove the contrary. ] ] ]Let me try this again: your historical argument is just bullshit. The ]reasoning is vacuous, independent of the truth of the conclusion. Ah, objectivity. ]if they really would be profitable.) Space resources? We went ]to the moon and found... very little of practical value. Space Gee. We sent six missions to the moon and found nothing so that means that there is nothing of value on the moon? Do you define "practical" as "everything jumps out of hiding at you"? There haven't been enough surveys done on the moon for you to simply jump to the conclusion that there is nothing of practical value on the moon. But then, I am nothing but a mere history undergraduate so I guess I've missed something. BTW, aren't there other places besides the moon to look for things? Things that make us go? :) ]manufacturing? Endlessly hyped with little to show for it. Has it been tried at any level for you to make that sort of conclusion? ]You advance the straw man argument that I am arguing that there will ]never be any benefits. As you say, we can't know that. But lack of ]certainty doesn't mean we are absolved from the need to make decisions ]on how scarce funds are expended. You can't just say "you can't prove ]me wrong, so gimme." At least, not with a straight face. I find it amazing that you can say "you can't prove it so NO!" with a straight face. You have to try first. -- Patrick Chester |---------------------------------------------------- wolfone@ccwf.cc.utexas.edu |"The earth is too fragile a basket in which to keep Politically Incorrect | all your eggs." Robert A. Heinlein Future Lunar Colonist |"The meek can *have* the Earth. The rest of us are #^%$!! Militarist | going to the stars." Robert A. Heinlein (Of the Sun Tzu mentality) |---------------------------------------------------- ------------------------------ Date: Thu, 31 Dec 92 18:35:31 GMT From: Dave Jones Subject: Justification for the Space Program Newsgroups: talk.politics.space,sci.space Joe Trott (joet@dcatlas.dot.gov) wrote: > dj@ekcolor.ssd.kodak.com (Dave Jones) writes: > > >John McCarthy (jmc@SAIL.Stanford.EDU) wrote: > >> Let me add to the previous post the estimate that the total amount of > >> matter humanity has processed in its history is less than 10^12 tons. > >> -- > >> John McCarthy, Computer Science Department, Stanford, CA 94305 > >> * > >> He who refuses to do arithmetic is doomed to talk nonsense. > >> > >So let's do arithmetic: assume 5e10 people have lived to date. That's > >20 tons per person across all of human history. Divide by a human life: > >0.5 to 0.3 tons per year. Say a few pounds a day. Well, I think we know > >what kind of processing this number figures to represent. Alimentary, my > >dear Watson. > > That sounds like a lot of crap to me! > > (Sorry, I couldn't resist...:)) > That's OK. You probably had a case of the trots..... -- ||------------------------------------------------------------------------ ||Dave Jones (dj@ekcolor.ssd.kodak.com)|Eastman Kodak Co. Rochester, NY | ------------------------------ Date: 31 Dec 92 16:46:40 GMT From: Gary Coffman Subject: Justification for the Space Program Newsgroups: talk.politics.space,sci.space,alt.rush-limbaugh In article jmd@bear.com (Josh Diamond) writes: > >Did it ever occur to anyone out there to consider the environmental >impact of large scale disruption of the sea floor? I could result in >severe problems with algal blooms and plankton die-offs, with effects >all the way up the food chain... The deep sea bottom is one of the most barren deserts on Earth, except around certain volcanic vents. If the materials can be mined without pumping large amounts of muck to the surface and discharging it in near surface waters, there should be minimal environmental impact. That means semi-autonomous submersible harvesters, a tough but not impossible task. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | emory!ke4zv!gary@gatech.edu ------------------------------ Date: 31 Dec 92 20:18:15 GMT From: David Toland Subject: Moon Dust For Sale Newsgroups: sci.space In article <1992Dec30.175447.5258@news.arc.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >Superior Galleries in Beverly Hills, California is having an auction >of space memorabilia on January 11, 1993. One item of particular interest >is a 2 inch piece of transparent tape which has some Moon dust on it. This is >the first time that Moon dust is being offered for sale. The Moon dust >was collected by a NASA technician from the spacesuit of astronaut Dave Scott >after his Apollo 15 trip to the Moon in July, 1971. It is guarantteed >to be genuine by Superior Galleries and is expected to be sold >in the price range of $75,000 to $100,000. For more information on the >Moon dust or the auction, you can contact Superior Galleries at >(800) 421-0754 or (310) 203-9855. Out of curiosity, just how do they "guarantee it to be genuine", if it's from an unofficial source, as it appears to be? How would one know that the technician didn't just glob up some rock dust sterilized in a crucible? Provenance would appear to be difficult, especially if there's a legal position that might lead to incrimination of the techie for theft of government property. -- -------------------------------------------------------------------------- All opinions are MINE MINE MINE, and not necessarily anyone else's. det@phlan.sw.stratus.com | "Laddie, you'll be needin' something to wash | that doon with." ------------------------------ Date: Thu, 31 Dec 1992 18:46:56 GMT From: Paul Dietz Subject: Public support for the space program Newsgroups: sci.space,talk.politics.space In article <1992Dec30.230013.4102@aio.jsc.nasa.gov> Dr. Norman J. LaFave writes: >> The *relative* support of the space program is not very high. > Another Dietz assertion-without-proof... Please > provide data which shows the relative support. Okay! From Gallup Report #289, October 1989, pages 4-10. This poll asked 1,234 Americans what categories of public spending they would like to see increased. The results: Education 76% Drugs 75 Homeless 71 Health Care 67 Pollution 59 AIDS 59 Job Training & Placement 56 Help low-income families 56 Aid farmers 48 Health insurance 48 Aid college students 44 Child care services 41 First-time home buyers 37 Space exploration 21 Defense spending 17 When a subgroup was asked if they were willing to pay additional taxes to increase federal spending for an item, suport for space exploration was also next to last, at 13% (the top 4 categories in the list remained above 50%). Another poll conducted July 1990 (The Gallup Poll Monthly, Sept. 1990, pages 44-45) showed a decline in support for the space program. In response to the question "On the whole, do you feel our investment in space research is worthwhile or do you think it would be better spent on domestic programs such as health care and education?", the response was: Year Worthwhile Domestic No opinion 1989 43% 52 5 1990 39 57 4 In response to the question "I am going to ask you a question about government spending. In answering, please bear in mind that sooner or later all government spending has to be taken out of the taxes that you and other Americans pay. Thinking about the US space program, tell me whether the amount of money now being spent for that purpose should be increased, kept at the present level, reduced, or ended altogether?" Year Increase Same Reduce End No Opinion 1984 21% 48 23 5 3 1986 26 50 14 5 5 1989 27 42 22 4 5 1990 17 37 32 10 4 I imagine the jump in 1986 was a result of the Challenger disaster. The polling data does show that the public favors manned (48%) over unmanned (34%) programs. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 31 Dec 92 19:49:58 GMT From: "John S. Neff" Subject: Public support for the space program Newsgroups: sci.space,talk.politics.space In article <1992Dec31.184656.14629@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >From: dietz@cs.rochester.edu (Paul Dietz) >Subject: Public support for the space program >Date: 31 Dec 92 18:46:56 GMT >In article <1992Dec30.230013.4102@aio.jsc.nasa.gov> Dr. Norman J. LaFave writes: > >>> The *relative* support of the space program is not very high. > >> Another Dietz assertion-without-proof... Please >> provide data which shows the relative support. > > >Okay! > >From Gallup Report #289, October 1989, pages 4-10. > >This poll asked 1,234 Americans what categories of public spending >they would like to see increased. The results: > > Education 76% > Drugs 75 > Homeless 71 > Health Care 67 > Pollution 59 > AIDS 59 > Job Training & Placement 56 > Help low-income families 56 > Aid farmers 48 > Health insurance 48 > Aid college students 44 > Child care services 41 > First-time home buyers 37 > Space exploration 21 > Defense spending 17 > >When a subgroup was asked if they were willing to pay additional taxes >to increase federal spending for an item, suport for space exploration >was also next to last, at 13% (the top 4 categories in the list >remained above 50%). > >Another poll conducted July 1990 (The Gallup Poll Monthly, Sept. 1990, >pages 44-45) showed a decline in support for the space program. >In response to the question > > "On the whole, do you feel our investment > in space research is worthwhile or do you think it would be better > spent on domestic programs such as health care and education?", > >the response was: > > Year Worthwhile Domestic No opinion > 1989 43% 52 5 > 1990 39 57 4 > >In response to the question > > "I am going to ask you a question about government spending. > In answering, please bear in mind that sooner or later all > government spending has to be taken out of the taxes that you > and other Americans pay. Thinking about the US space program, > tell me whether the amount of money now being spent for that purpose > should be increased, kept at the present level, reduced, or ended > altogether?" > > Year Increase Same Reduce End No Opinion > 1984 21% 48 23 5 3 > 1986 26 50 14 5 5 > 1989 27 42 22 4 5 > 1990 17 37 32 10 4 > >I imagine the jump in 1986 was a result of the Challenger disaster. > >The polling data does show that the public favors manned (48%) over >unmanned (34%) programs. > > Paul F. Dietz > dietz@cs.rochester.edu The polls that I was quoting were joint ventures by The New York Times and one of the networks either CBS or NBC. There are also polls by NASA and by Space Advocacy Groups that show support for the manned space program at about the 55% level. However when asked if the funding level should be increased, kept the same, or reduced. Increased comes in last and kept the same is first. NASA and the contractors for the space station are concerned about the loss of some of their strong supporters in congress. If the new members of congress have views that are similar to those indicated in the Gallup poll it may be difficult for NASA to get another budget increase. ------------------------------ Date: 31 Dec 92 23:05:39 GMT From: Brian Yamauchi Subject: Public support for the space program Newsgroups: sci.space,talk.politics.space In article <1992Dec30.230013.4102@aio.jsc.nasa.gov> Dr. Norman J. LaFave writes: >>> The *relative* support of the space program is not very high. > >> Another Dietz assertion-without-proof... Please >> provide data which shows the relative support. > >Okay! The general consensus seems to be that public support for space exploration is wide but not deep. The majority of the people _do_ support government spending on space exploration, but only a small minority place it among their top priorities. The polling data presented does support Paul's claim that the relative importance that most people place on space exploration is low compared to the importance they place on more earthbound programs. On the other hand... > In response to the question > > "I am going to ask you a question about government spending. > In answering, please bear in mind that sooner or later all > government spending has to be taken out of the taxes that you > and other Americans pay. Thinking about the US space program, > tell me whether the amount of money now being spent for that purpose > should be increased, kept at the present level, reduced, or ended > altogether?" > > Year Increase Same Reduce End No Opinion > 1984 21% 48 23 5 3 > 1986 26 50 14 5 5 > 1989 27 42 22 4 5 > 1990 17 37 32 10 4 Even this data shows that a majority of the people (54%) support spending at least as much as we currently do on space exploration. In addition, another Gallup poll (quoted in Ad Astra about a year ago), indicated that the public drastically overestimates the amount of money being spent on space exploration. Average estimates were in the 5-10% range, when the actual figure is closer to 1%. Personally, I believe that current spending levels ($14 billion/year) could fund a vigorous, ambitious, manned and unmanned program of orbital, lunar, and interplanetary exploration and development -- if it were being spent properly... 5% of the federal budget ($60 billion/year) -- which most people seem to feel is a reasonable proportion, if these polls are correct -- could fund a fantastic space program -- but again, only if it were spent in the right ways and on the right things... Followups are directed to talk.politics.space. -- _______________________________________________________________________________ Brian Yamauchi Case Western Reserve University yamauchi@alpha.ces.cwru.edu Department of Computer Engineering and Science _______________________________________________________________________________ ------------------------------ Date: 31 Dec 92 19:05:00 GMT From: Pat Subject: Sea floor Planetary Protection really. Newsgroups: sci.space In article roberts@cmr.ncsl.nist.gov (John Roberts) writes: > > >By the way, before I forget - I recently saw an old (1960s) clip on NASA >Select, discussing the sterilization of unmanned probes for exploration of >planetary surfaces (so as to avoid contaminating possible native life before >studies could be conducted). The plan at that time was to sterilize the >probes by exposing them to ethylene oxide gas. Items such as sensors that >might be sensitive to ethylene oxide could be sterilized by other means, >and covered during exposure to the gas. NASA has adopted the COSPAR guidelines on planetary protection and i believe even has an office for this. They are concerned about contamination in both ways. They reccomend, heat sterilization, radiation, gas and chemicals. The big concern now is not so much establishing earth organisms on foreign bodies, but destroyin/contaminating archaeology studies of exo-biology. I know the Mars Observer orbit was constrained under planetary protection guidelines to stay off the surface for X thousand years. ------------------------------ Date: Thu, 31 Dec 1992 19:25:22 GMT From: Dillon Pyron Subject: Space List Flame Wars Newsgroups: sci.space Flame wars? Flame Wars?! You think these are flame wars? Go over to comp.os.vms. There are some beauts running over there! -- Dillon Pyron | The opinions expressed are those of the TI/DSEG Lewisville VAX Support | sender unless otherwise stated. (214)462-3556 (when I'm here) | (214)492-4656 (when I'm home) |"Pacts with the devil are not legally pyron@skndiv.dseg.ti.com |binding!" PADI DM-54909 |-Friar Tuck _Robin Hood:The Hooded Man_ ------------------------------ Date: 31 Dec 92 19:29:48 GMT From: "Edward V. Wright" Subject: SSTO vs 2 stage Newsgroups: sci.space In <1992Dec31.182358.13827@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >You are apparently tossing in the assumption that stacking will be >very expensive. This assumption may very well be true, but you have >not justified it. If you want justification, leave our office, drive out to the local airport (or truck stop), and look at the sort of routine maintenance that real transportation systems require. To turn an airliner around between flights, they unload the passengers, refuel, vacuum the interior, and run through the preflight checklist. Unless something unexpected crops up, that's all they do. Any additional maintenance, even something as a new coat of paint, would more than double the operating cost. More complex work, like stacking and mating stages, would probably increase it by a factor of 10. ------------------------------ Date: Thu, 31 Dec 1992 19:54:55 GMT From: Bruce Dunn Subject: SSTO vs 2 stage Newsgroups: sci.space Regarding my assumption that SSTO proposals based on the Saturn S-IVB would be non returnable and non-reusable, Henry Spencer writes: > > No, some of the S-IVB-based SSTO proposals were reusable. I don't know > how well they would have worked, and I don't know that I'd plan a spaceline > based on them without waiting a while to see how reusable they really were, > but on paper it was feasible. I stand corrected, although somewhat puzzled. If you have the details handy Henry, could you inform us how it was planned to recover a cylindrical stage without having it break up the way the Shuttle ET breaks up when it hits the atmosphere? Presumably this must involve some mechanism for keeping the stage oriented and tumble free during re-entry. What heat shield materials were planned in this era prior to the Shuttle tiles and blankets? -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca ------------------------------ End of Space Digest Volume 15 : Issue 620 ------------------------------