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) ID ; Fri, 7 Jun 91 03:14:35 -0400 (EDT) Message-ID: <4cHn9JK00WBw4jB05c@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 7 Jun 91 03:14:29 -0400 (EDT) Subject: SPACE Digest V13 #613 SPACE Digest Volume 13 : Issue 613 Today's Topics: Re: Saturn V and the ALS Gravity vs. Mass Re: New Subject--Solar Collectors/Antimatter Re: Hypersonics ... paritcularly Hotol Re: lifeboats Re: Keck (was Re: Privatization) Re: 2001 and "The Endeavor" Re: Scale models Grinding Axes and Picking Bones 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: 21 May 91 08:07:43 GMT From: agate!maelstrom.Berkeley.EDU!fcrary@ucbvax.Berkeley.EDU (Frank Crary) Subject: Re: Saturn V and the ALS In article <1991May20.192813.1044@iti.org> aws@iti.org (Allen W. Sherzer) writes: >If wisely selected I don't see any problems. We would set up a LLNL >inflatable station and a series of free-flyers. The main station would >be used to house crew, perform life sciences work, house a 0G dry dock >and some microgravity (so experimenters can see their experiment in >real time and make changes). Outside would be a number of free flyers >for microgravity, manufacturing, and a fuel depot. You would need to >insure that everybody is compatable but it wold reduce costs to share >the basic facilities. Insureing that everybody is compatable is exactly the problem. For example, in the Freedom design, someone (A congressional administrative assistant with lost of pull, if I rememble correctly) said "There is not way you are going to put a centrafuge into the microgravity lab. It will mess up the materials processing experiments. (Which are what _I_ think is important.)" Since there was no clear directive as to the purpose of Freedom, those designing the lab could not say either "Too bad, this is a zero-g biology lab. Dump the materials processing stuff that can't take the vibrations" or "Ok, since this is a materials processing lab, we'll dump the zero-g bio people's centrafuge." As a result, they had to spend a lot of time and effort to design and place a centrafuge that would be usefull to the zero-g bio people, but would not compromise the materials processing experiments. Is this really the sort of can of worms you want to open? Frank Crary UC Berkeley ------------------------------ Date: 21 May 91 05:31:05 GMT From: swrinde!zaphod.mps.ohio-state.edu!samsung!umich!ox.com!math.fu-berlin.de!msi.umn.edu!cs.umn.edu!ub.d.umn.edu!jrowliso@ucsd.edu (Isildur) Subject: Gravity vs. Mass I was having a debate with one of my friends over this one... You somehow dug a hole clean through the earth in a diameter through the core and it was completely insulated from the heat changes running through the planet. When you climbed into the tunnel (fall into the the tunnel...) and reach the center of the planet, would your weight be incredibly multiplied because of your new relative location to the center of the earth (using the mass/gravitational constant formula) or would you have zero-weight because you were surrounded by virtually identical mass (and also assuming that the tunnel closes up outside your immediate location)? ------------------------------------------------------------------------------ jrowliso@ub.d.umn.edu | "So many questions, so little | time!" ------------------------------------------------------------------------------ ------------------------------ Date: 15 May 91 16:54:49 GMT From: elroy.jpl.nasa.gov!swrinde!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss!Paul.Blase@lll-winken.llnl.gov (Paul Blase) Subject: Re: New Subject--Solar Collectors/Antimatter to: f3w@mentor.cc.purdue.edu (Mark Gellis) MG> I have a question or two regarding possible future applications MG> of solar power. Robert Forward suggests that it is possible to MG> produce antimatter with a reasonable degree of efficiency. His MG> design, however, calls for a lot of power. The key is to get the power where it it cheap (a solar power satellite or a terrestrial power plant) and use the antimatter where it is needed (in space-propulsion applications where you need speed and can't afford a large fuel mass). MG> Now, since the use he suggests for antimatter is rocket fuel Strictly speaking: the matter/antimatter annihilation is used to heat the reaction mass. MG> (his argument, which MG> I accept, is that it is so expensive that fusion and solar are MG> really much better for most other power requirements), it makes MG> sense to bring in other space-related technologies. If you MG> have a space-based economy a few hundred years down the line, MG> you need a LOT of antimatter if you want people zipping around MG> the solar system..... Important note: the use of antimatter is NOT that it deliveres 'more power', but that it packages a LOT of power into a small space; it is particularly useful for missions such as solar-impact probes and orbit reversing (leaving orbit and catching up with a target going the other direction) that would not be possible if you had to accelerate a large fuel load in addition to the payload. MG> My question regards the efficiency of solar collectors. Now, MG> obviously, technology will change and improve during the next MG> few centuries, but based on what we know today about such solar MG> power cells... MG> 1) Given a solar cell that will produce 10 kilowatts in MG> Earth orbit, would the same cell (i.e., the same mass of MG> finished product) produce more power if it was moved to Venus MG> orbit, where it would be getting more than twice as much MG> energy from sunlight? (If power is the wrong word, I MG> apologize; you know what I mean, though.) Will it produce 20+ MG> kilowatts now? Do the cells have a limit on how much MG> electricity they will produce, or will they just keep giving MG> you more power if you increase the solar energy per square MG> meter? There is a limit, but in general photovoltaic cells operate most efficiently at very high light levels. This is why many new solar-cell designs use concentrators (mirrors) to increase the light flux at the cell. The closer you are to the sun, obviously, the smaller a system you need for a given amount of light on your cell. MG> 2) If you can get more energy from solar cells by moving MG> them closer to a star, what is the limit? When your cell melts, or other thermal effects start to cut into the efficiency. Don't forget that there is another way of producing electricity from sunlight: dynamic power, aka a steam turbine. I think that it is a toss up as to which would be cheaper right now. --- via Silver Xpress V2.26 [NR] -- Paul Blase - via FidoNet node 1:129/104 UUCP: ...!pitt!nss!Paul.Blase INTERNET: Paul.Blase@nss.FIDONET.ORG ------------------------------ Date: 21 May 91 18:03:35 GMT From: agate!spool.mu.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: Hypersonics ... paritcularly Hotol I wrote: >There was talk about a Hotol derivative using conventional rockets launched >from the back of an Antonov Mriya. This would have avoided the problematic >engine technology proposed for the original. Favorable noises were being >made about it, but I have heard nothing recently. Rumor (via email) hath it that aerodynamic problems killed the idea, but I have no details. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 21 May 91 18:20:00 GMT From: agate!spool.mu.edu!think.com!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: lifeboats In article <1991May20.184528.19548@agate.berkeley.edu> gwh@tornado.Berkeley.EDU (George William Herbert) writes: >>The one SM function that would have to be provided by new hardware would >>be retrofire. The obvious method is a set of small solid motors a la Gemini. > >You're forgetting something... all the orbital maneuvering (reaction control >system etc) was on the SM if I remember correctly... Nope, not correct. The CM had its own RCS for reentry. If you want to do orbital maneuvering -- it's not clear why -- then yes, you'd have to add something for that. Take the RCS thruster "quads" from the SM, which were self-contained (each quad had its own little tank set just underneath it) and put them on whatever adapter you're using to hold the solid retros. >... I'm not sure how happy the >astronauts would be about dropping hydrazine in their capsule for RCS >purposes... There were in fact a couple of incidents in which RCS propellant venting after parachute deployment contaminated the cabin air and made some of the astronauts sick. I think they sorted this out by some procedural revisions. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 22 May 91 04:21:51 GMT From: att!pacbell.com!mips!samsung!dali.cs.montana.edu!ogicse!sequent!muncher.sequent.com!szabo@ucbvax.Berkeley.EDU Subject: Re: Keck (was Re: Privatization) In article <1991May21.235606.3804@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes: >[scopes vs. probes] >Sure, there are >questions that can only be answered on-site, but the questions the >telescopes are trying to address (the fate and nature of the universe >as a whole) seem more fundamental. The "fundamentalism" of the science is not the fundmental issue here, if you'll pardon me. :-) Exploration -- including exploration through telescopes -- can be done for reasons ranging from fundamental science to a totally industry-oriented project. Oil exploration is a contemporary example of the latter. I won't get into the "pure" vs. "applied" issue here. The point is that practical exploration may follow a similar technological pattern as fundamental exploration. One applied problem, for example, is increasing the number of known earth-crossing asteroids, in order to find those with the minimum impulse delta-V to earth orbit. For this problem, an array of telescopes with CCD's can be more cost-effective than onsite probes. Other problems, both scientific and applied, can be better solved by probes. There is no "fundamental" (there's that word again :-) reason why applied explorers would favor on-site inspection any more than the pure science explorers. -- Nick Szabo szabo@sequent.com "If you understand something the first time you see it, you probably knew it already. The more bewildered you are, the more successful the mission was." -- Ed Stone, Voyager space explorer ------------------------------ Date: 22 May 91 15:43:04 GMT From: sdd.hp.com!wuarchive!news.uu.net!mcsun!ukc!icdoc!syma!nickw@ucsd.edu (Nick Watkins) Subject: Re: 2001 and "The Endeavor" From article <830@newave.UUCP>, by john@newave.UUCP (John A. Weeks III): > something worth checking out. According to the book, even when NASA had > a clear cut goal to chase, they still wandered around aimlessly. The more > things change, the more things stay the same.... Not sure if NASA exists in 2001/2010 books, Heywood Floyd works for an outfit called the NCA, National Commission on Astronautics (?). Nick -- Dr Nick Watkins, Space Plasma Physics, Univ. of Sussex, Brighton BN1 9QH, UK JANET: nickw@uk.ac.sussex.syma BITNET: nickw%syma.sussex.ac.uk@uk.ac ------------------------------ Date: 22 May 91 15:32:24 GMT From: usc!elroy.jpl.nasa.gov!sdd.hp.com!wuarchive!news.uu.net!mcsun!ukc!icdoc!syma!nickw@ucsd.edu (Nick Watkins) Subject: Re: Scale models From article <1991May9.162848.4105@cpsc.ucalgary.ca>, by gaston@fsd.cpsc.ucalgary.ca (Gaston Groisman): > I am wondering about the existance of scale models of the Hubble Space > Telescope and the Voyager space craft. Has anybody seen these in any > hobby shop? No, but an advert in recent copy of Fine Scale Modeller announces the Voyager 1/35 scale kit from : Lunar Models 5120 Grisham Rowlett TX 75088 USA tel 214 475 4230 or in US 1 800 662 4984. Please post if you find out more Nick -- Dr Nick Watkins, Space Plasma Physics, Univ. of Sussex, Brighton BN1 9QH, UK JANET: nickw@uk.ac.sussex.syma BITNET: nickw%syma.sussex.ac.uk@uk.ac ------------------------------ Date: Wed, 22 May 91 20:34:20 PDT From: jim@pnet01.cts.com (Jim Bowery) To: crash!space+@andrew.cmu.edu Subject: Grinding Axes and Picking Bones Someone asked me what axe I'm grinding. Maybe I should come clean: I was born and raised in a small Iowa town. You know... we didn't lock our doors at night, etc. I believed the things they taught me in civics class about American values. When I confronted the cynical "realpolitick" that has consumed our society and its future from the top down in the form of NASA, I decided maybe I should exercise my right of free speech, right of petition, etc. Despite the inconvenience this may cause to some, I'm not going to apologize for being rather insistent that traditional American values be followed in the one place they count the most: Opening our next frontier. I consider this important enough to take action on because I really do think space is our destiny and best hope of survival, but I don't think it is "inevitable" that we will make it. We're clearly in crisis mode. How does this relate to Space Station Fred? Republicans who support the space station program fit the definition of "conservative" as it is used in the Soviet Union. They want to "conserve" the bureaucratic structures that benefit their friends by suppressing freedom with doublespeak like "Freedom". Enterprises such as Spacehab, Space Industries Inc. and other nascent microgravity service companies were beaten into submission by NASA and then captured by former "leaders" of Space Station program prime contractor McDonnell Douglas such as James Rose and Jake Jacobson as well as the NASA administrator that initiated Fred as an "all things to all people in all Congressional districts" porkbarrel juggarnaut: James Beggs. For a wonderful, heart-warming history of the way these parasites were so "helpful" to the SII/ISF and Spacehab, I refer you to current issue of the "Air and Space" magazine from that libelous radical fringe group: the Smithsonian. I have my own experiences with employees of McDonnell Douglas who have engaged in similar "promotional" activities on behalf of Fred. This kind of bureaucratic suppression of free enterprise is all too familiar to people who are trying to create free markets in eastern Europe and USSR. The problem is even worse with NASA because of all the doublespeak/doublethink that started with the program under Mr. Free Enterprise himself, Ronald Wilson Reagan, in that banner year for space: 1984. Fred isn't mere socialism, where the government has some ownership but little control, as in Sweeden. The space station is hard-core communism with burueacratic ownership and management, shielded by a thin veil of aerospace "contractors" who are little more than extensions of the government agencies that employ them. In particular, the following, Republican members of the VA HUD and Independent Agencies subcommittee of the Senate Appropriations committee have demonstrated, by their support of programs like Fred, that they are practicing de facto communists despite their party affiliation: Cosmonaut Jake Garn 202/224-5444 Alfonse D'Amatoff 202/224-6542 Donsky Nickles 202/224-5754 Phil Grammivich 202/224-2934 Christopher "Vlad" Bond 202/224-5721 If anyone else still believes traditional American values are the best way of opening frontiers like the West and space, you might give these guys a call and ask them when they would like a copy of "Das Kapital" as a guide-book to the correct management of monolothic government bureaucracies like NASA. They clearly aren't as competent at being a central party member as the guys in the USSR given the relative performances of Mir and Fred. Maybe we should do a foreign exchange: NPO Engergia managers come here to teach us how to run a communist space program like NASA, in exchange for some of our commodities brokerage experts. On the other hand, maybe we should just "Axe" Fred. ----------------------------------------------------------------------------- Jim Bowery 619/295-3164 The Coalition for PO Box 1981 Science and La Jolla, CA 92038 Commerce ----------------------------------------------------------------------------- ------------------------------ End of SPACE Digest V13 #613 *******************