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 ; Mon, 6 May 91 01:31:25 -0400 (EDT) Message-ID: <8c9CcYS00WBwI-l04h@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 6 May 91 01:31:17 -0400 (EDT) Subject: SPACE Digest V13 #489 SPACE Digest Volume 13 : Issue 489 Today's Topics: United Space Federation, Update 5/1/91 Status of Space Station FAQ Response Effort Re: Terraforming Mars? Why not Venus? Re: Gas Guns and Tethers Re: Terraforming Venus GIF viewer Re: Atlas Centaur bites the big one, 4/18 Re: Tethers Re: Saturn V and Design Reuse: Saturn VI? (RBB: Real Big Booster) Re: Tethers Re: GREAT IDEA Re: Galileo works? Re: Terraforming Venus? 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: 1 May 91 05:36:48 GMT From: vax5.cit.cornell.edu!usf@cu-arpa.cs.cornell.edu Subject: United Space Federation, Update 5/1/91 ******************************************************************************** United Space Federation, Inc. Update no. 1 May 1st 1991 ********************************************************************************* Hello!, this is how all future reports will be listed in the news net, see listing International Space Agency by 1993 in this section for more information. Testing One, Two, Three! ------------------------------ Date: 1 May 91 12:38:58 GMT From: agate!bionet!uwm.edu!zaphod.mps.ohio-state.edu!caen!news@ucbvax.Berkeley.EDU (Ken Sheppardson) Subject: Status of Space Station FAQ Response Effort Some of you may recall that several days ago I offered to attempt to create a Frequently Asked Questions document specific to Space Station. Don't hold your breath. I just watched a tape of the Senate science subcommittee hearings held on (April 16?) where Truly, Lenoir, Thompson, Kohrs, and Fisk all testified on space station. Given their testimony, I don't think it's humanly possible to put together a document which gives 'correct' (let alone consistent) answers to the sort of questions people bring up here on the net (which are in many ways quite similar to those asked by Senators). So...back to our regularly scheduled rumor, conjecture, and opinion... :) =============================================================================== Ken Sheppardson Email: kcs@sso.larc.nasa.gov Space Station Freedom Advanced Programs Office Phone: (804) 864-7544 NASA Langley Research Center, Hampton VA FAX: (804) 864-1975 =============================================================================== ------------------------------ Date: 1 May 91 15:12:22 GMT From: mips!swrinde!zaphod.mps.ohio-state.edu!ub!ubvmsc.cc.buffalo.edu!v096my2q@apple.com (Mark A Wieczorek) Subject: Re: Terraforming Mars? Why not Venus? In article <1991Apr30.222347.14766@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes... >In article <1422@nih-csl.nih.gov> sullivan@alw.nih.gov (Sullivan) writes: >> I was wondering why we'd want to terraform a planet for human >> habitation when the gravity there is 1/4th of earth's. >> Wouldn't this cause problems for humans living there? > >Good question. Nobody knows. The odds are that it would, at the very >least, result in relatively weak bones, and other problems are likely. Does it really matter if the skeletal system becomes week if you continue to live on mars for the duration of your life? Maybe I'm wrong, but it seems that the problem with astronauts and calcium depletion is that they have to return to Earth at some time. If they are not active enough in space this could be a big shock when they are suddenly exposed to gravity again. Does anyone know of any other biological problems that would be significant to an astronaut that decided to live in space and not return to Earth? Mark Wieczorek ------------------------------ Date: 1 May 91 15:33:25 GMT From: news-server.csri.toronto.edu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Gas Guns and Tethers In article waltdnes%w-dnes@torag.uucp writes: >Theoretical problem 1) The centre-of-mass of the combined structure has >instantaneously dropped closer to the earth's surface without the orbital >velocity increasing. The result should be a lower orbit. There are a variety of low-thrust high-exhaust-velocity propulsion systems that are useless for boost from Earth's surface but are eminently suited to slowly raising that orbit back up again. This does mean that some fraction of your payload to orbit has to be fuel for the orbit-raising system, but the high exhaust velocity means that the fraction is not 100% or anywhere near it. >As the shuttle climbs the tether, the space-station+tether descend a bit. >Since we're dealing with a closed system, the centre-of-mass must remain >in the same orbit. In this case, the orbit lowering is temporary, because you return the shuttle to the ground by reversing the process. (That also eliminates the need to carry along fuel for retrofire.) >Practical problem 1) Conservation of angular momentum... Unless the >shuttle matches velocity *VERY* closely with the station, the two bodies >will be spinning around each other at some horrendeous rpm's by the time >the shuttle has climbed all the way up the tether. The simple fix is just to make the station very much heavier than the shuttle. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 1 May 91 21:10:45 GMT From: dog.ee.lbl.gov!hellgate.utah.edu!caen!math.lsa.umich.edu!zaphod.mps.ohio-state.edu!ub!ubvmsc.cc.buffalo.edu!v096my2q@ucbvax.Berkeley.EDU (Mark A Wieczorek) Subject: Re: Terraforming Venus In article <1991May1.173813.17587@en.ecn.purdue.edu>, irvine@en.ecn.purdue.edu (/dev/null) writes... > >I think Venus might be a bit easier to Terraform than Mars. With Mars, you >have to find a way to add air pressure, with Venus, you have to find a >way to decrease it (never minding the fact that both are poisonous >right now ... :) ) > >This could be an opportunity to try out bio-technology. Send a group of >microbes that "eat" sulphur in sulphuric acid, cleaning the air. Sending microbes to venus may help clean up the air, but I can't imagine it having much of an effect on the atmospheric pressure or surface temperature. Supposively, Venus, Mars and Earth at one time had the same amount of water on the planet. Since venus receives about twice? as much solar energy as Earth the water has vaporized which causes the huge atmospheric pressure, while on mars it may be frozen out in the polar caps and soil. I think the main issue here is to first heat up the martian surface by throwing in some CFC's or something similar, or possibly permanently shielding venus from the sun. After the atmosphere is normalized by human standards then we can worry about wether or not it's or not and how we would go about cleaning up that. Also when people talk about bombarding either mars or venus with comets. Where are they going to come from and how are they going to get here? Is their any evidence that their actually is an oort cloud, or is this just a nice hypothesis? Mark Wieczorek ------------------------------ Date: 1 May 91 21:40:38 GMT From: psuvm!gws102@psuvax1.cs.psu.edu Subject: GIF viewer Does anyone know where I can get a GIF viewer for a MAC, IBM, and/or UNIX works tation. Information on any of these computer formates would be appreciated. Glenn Szydlowski GWS102@PSUVM.PSU.EDU Penn State University ------------------------------ Date: 1 May 91 17:08:32 GMT From: mcsun!ukc!icdoc!syma!nickw@uunet.uu.net (Nick Watkins) Subject: Re: Atlas Centaur bites the big one, 4/18 From article <1991Apr19.155204.15985@zoo.toronto.edu>, by henry@zoo.toronto.edu (Henry Spencer): > Incidentally, KSC launches shuttles and only shuttles. All other launches > are from the Cape Canaveral USAF base. For KSC *the piece of ground*, this is true. For KSC *the organisation* this is not completely true, as they are *involved* in expendable launches of NASA or part-NASA payloads (e.g. CRRES), from Cape Canaveral Air Force Station. The USAF does indeed have the veto on range safety, and GD are responsible for Atlas launch control from the blockhouse at pad 36, working closely with USAF personnel. It is interesting to note, though, that the Delta II launch pads seem to have a USAF badge rather than the NASA badge they used to carry, a reflection of the fact that the Delta launches are now by McDonnell Douglas for the USAF rather than by McDonnell Douglas and the USAF for NASA, which seems to be the closest approximation to the organisational shift ? Sorry to be picky but the distinction betweeen KSC the site & KSC the administrative entity is real, and was more so in the days before "commercial" launches of Atlas & Delta. Nick -- ------------------------------ Date: 25 Apr 91 03:35:16 GMT From: unisoft!fai!sequent!crg5!szabo@ucbvax.Berkeley.EDU (Nick Szabo) Subject: Re: Tethers In article <58E59D9D9C000064@BITNET.CC.CMU.EDU> F026@CPC865.EAST-ANGLIA.AC.UK (F026) writes: > Nick Szabo's explanation of tethers in space misses the *really* interesting >part for LEO users: if you have a longish (>1000m) tether orbiting within a >magnetic field, eg LEO, an electrical potential is induced (at the cost of >orbital velocity)....[use orbital energy as battery for use inside shadow] I don't know about the *really* part, :-), but you point out another interesting and quite promising use of tethers that I had failed to mention. I was bound to miss some of 'em. For this application, as well as EML, magsails, etc., increased R&D on superconducting materials is very important, as well as R&D on high tensile strength materials for tethers in general. Paul Dietz and I have worked on his proposal for tapping the large kinetic energy of Jupiter's inner moons, via Jupiter's strong magnetic field, using a similar scheme. The energy available, and readily extractable, is at minimum millions of megawatts for over a thousand years. I have also proposed a scientific "astronomy flashlight" mission that could take advantage of the magnetic flux with a small probe in the near term. While this is not directly related to launch costs, a large inexpensive source of energy could become very important for second-generation space industry and colonization. Work on launch tethers could, in addition to reducing launch costs, very well "spin off" to the kinds of technology we are discussing here. -- Nick Szabo szabo@sequent.com "Living below your means allows you to live better than living above your means." -- Dave Boyd The above opinions are my own and not related to those of any organization I may be affiliated with. ------------------------------ Date: 2 May 91 18:49:31 GMT From: snorkelwacker.mit.edu!usc!samsung!noose.ecn.purdue.edu!en.ecn.purdue.edu!irvine@bloom-beacon.mit.edu (/dev/null) Subject: Re: Saturn V and Design Reuse: Saturn VI? (RBB: Real Big Booster) In article <1991May2.180311.5237@iti.org>, aws@iti.org (Allen W. Sherzer) writes: > > The driving force in launcher safety is NOT the lives of the crew. > Payload replacement cost IS the driving factor. The average payload > today is worth far more than the crews who launch it. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ What is your cost estimate of a crew member? :) Does it differ from males and females? How about levels of education (MS = $10000, PhD= $15000?) :) -- +-----------------------------------------------------------------------+ | Society of Philosophers, Luminaries, | Brent L. Irvine | | and Other Professional Thinking People..... | Only my own ramblings | +-----------------------------------------------------------------------+ ------------------------------ Date: 2 May 91 18:59:14 GMT From: dog.ee.lbl.gov!hellgate.utah.edu!caen!dali.cs.montana.edu!rpi!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!ub!uhura.cc.rochester.edu!rochester!dietz@ucbvax.Berkeley.EDU (Paul Dietz) Subject: Re: Tethers In article <21625@crg5.UUCP> szabo@crg5.UUCP (Nick Szabo) writes: >Paul Dietz and I have worked on his proposal for tapping the large kinetic >energy of Jupiter's inner moons, via Jupiter's strong magnetic field, >using a similar scheme. In all fairness, let me say the "worked on" means "have exchanged a few email messages about". Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 3 May 91 04:40:14 GMT From: agate!monsoon.Berkeley.EDU!fcrary@ucbvax.Berkeley.EDU (Frank Crary) Subject: Re: GREAT IDEA In article <91122.085040GIPP@GECRDVM1.BITNET> GIPP@gecrdvm1.crd.ge.com writes: >since if there ever was a real chance of such a booster coming into existence >all the established big launch companies along with any political power they >might command would be trying mighty hard to shut down Company X. Maybe >this is why none of those small startup companies with promising ideas >never get anywhere. shades of early automotive competition. Orbital Science Corp. is a "small startup company" which will begin operational launches of a new, inovative launcher later this year. For all the political power of "established big launch companies" the US government is one of OSC's biggest costumers. As far as one company, wich decides to build a cheap LV, cornering the launch market, there is no reason to think that what company X has done sucessfuly, company Y cannot also do. If the idea works, others will join in. Frank Crary UC Berkeley ------------------------------ Date: 3 May 91 13:00:53 GMT From: eru!hagbard!sunic!lth.se!newsuser@bloom-beacon.mit.edu (Magnus Olsson) Subject: Re: Galileo works? In article dlbres10@pc.usl.edu (Fraering Philip) writes: >In article jpc@fct.unl.pt (Jose Pina Coelho) writes: > >[I wrote:] >pg> I don't know, but maybe because the radio waves could become focused in >pg> such a way as to interfere with the spacecraft electronics. I don't know >pg> how much radio-frequency interference the circuits can take. > >and Jose Pina Coelho wrote: > >>They better be able to take a lot of it or they won't survive >>Jupiter's radiation belts (I mean, they are *strong* radiation >>fields, World War III would be peanuts arround Jupiter). > >I think you're confusing different sorts and frequencies of >e-m radiation. And things work differntly at different frequencies. It's even worse: He's confusing radio waves with ionizing radiation. The radiation belts of Jupiter, like the earth's Van Allen belts, contain a lot of electrically charged particles - electrons, protons etc. Making a piece of harware resistant to ionizing radiation like this is a totally different thing from making it resistant to radio frequency interference. Magnus Olsson | \e+ /_ Dept. of Theoretical Physics | \ Z / q University of Lund, Sweden | >----< Internet: magnus@thep.lu.se | / \===== g Bitnet: THEPMO@SELDC52 | /e- \q ------------------------------ Date: 3 May 91 23:25:57 GMT From: swrinde!elroy.jpl.nasa.gov!usc!jarthur!jhuyghe@ucsd.edu (Julien David Huyghe) Subject: Re: Terraforming Venus? Could a couple of HUGE fusion bombs (in the 1000 gigaton range) blast away 99% of Venus' atmosphere, leaving us with a manageable situation? Or is it just too much trouble launching a couple of aircraft-carrier-sized bombs? -- Julien David Huyghe, Pomona College '93 / Please let me dream Internet: pomona|spears|jarthur@claremont.edu / Let me scream GEnie: J.HUYGHE, CompuServe: 71760,3577 / Let me die --Mylene Farmer ------------------------------ End of SPACE Digest V13 #489 *******************