Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Tue, 3 Oct 89 04:23:17 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 3 Oct 89 04:22:55 -0400 (EDT) Subject: SPACE Digest V10 #103 SPACE Digest Volume 10 : Issue 103 Today's Topics: More linguistic tidbits Re: Galileo Jovian atmospheric probe -- is it sterilized??? Re: space news from Aug 14 AW&ST Re: Risk of NOT launching Galileo Re: Time Urgent: Voyager movies Oct 2 on satellite or tape Re: Mars Mission ship design Re: Risk of NOT launching Galileo Re: NIMF proposal from Martin Marietta YAHSS (Yet Another Henry Spencer Signature) Re: Plutonium in space (was Risk of NOT launching Galileo) Re: Alternative Space Goals, Anyone? (was Re: SpaceCause) ---------------------------------------------------------------------- X-Delivery-Notice: SMTP MAIL FROM does not correspond to sender. Date: Wed, 27 Sep 89 11:39:25 EST From: JC%RMC.BITNET@VMA.CC.CMU.EDU Subject: More linguistic tidbits So far I have seen Venerean, Venereal and even Cytherean, but what ever happened to Venusian? John Coughlin Net: JC@RMC.BITNET Vox: 613-541-6439 Fax: 613-547-3053 ------------------------------ Date: Wed, 27 Sep 89 14:47:07 PDT From: Peter Scott Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized??? cs.utexas.edu!mailrus!jarvis.csri.toronto.edu!csri.toronto.edu!wayne@tut.cis.ohio-state.edu (Wayne Hayes) writes: > So if there's "bugs" on Jupiter, >they're certainly deserving at least as much evolutionary "respect" as >anything on Earth, probably having evolved to a large degree as much as we >have. >[...] > I guess it is a somewhat subjective opinion (though one that >many people take *very* seriously, both with reason and strong emotion -- >just ask any "Trekkie" who believes in Gene Roddenberry's "Prime >Directive"), but I just strongly believe that we have no right to go >screwing around with an environment we know nothing about. Well, you don't get anywhere without taking risks, or the fish would never have crawled out of the ocean (credit: Hitch Hiker's Guide to the Galaxy). It all depends on whether the risk is worth the payoff. If we never trod on a new piece of ground because we were afraid of what we *might* squash, pretty soon we'd be shut up in our bedrooms, breathing quietly for fear that our next inhalation might capture the only remaining survivor of an incredible strain of bacteria which would be slain by our white corpuscles. Of course, taking this point of view to the other extreme leads to actions like the firing of the Amazonian rain forest, and to hell with their endangered species, so prudence is needed. However there is ample evidence that the A.R.F. contains unique and potentially valuable organisms which are destroyed by firing. The same cannot be said for Jupiter's atmosphere. What's needed is an exploratory probe to determine the composition of the latter and find out what *is* there... which appears to be what we are doing. If the Jovian microbes are so fragile that they would be destroyed by whatever terrestrial microbe manages to survive the trip, chances are that they wouldn't have made it anyhow... although I agree it would be nice to be able to study them. IMHO, the Galileo probe is far more likely to give us evidence for/against the existence of Jovian microbial life than to wipe it out, tho' from your posting I gather you agree with this viewpoint anyway. Peter Scott (pjs@grouch.jpl.nasa.gov) ------------------------------ Date: 26 Sep 89 12:57:32 GMT From: mcsun!ukc!icdoc!syma!nickw@uunet.uu.net (Nick Watkins) Subject: Re: space news from Aug 14 AW&ST In article <1989Sep25.014005.1837@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >STS-28 deploys advanced imaging spysat Aug 8. Satellite is an upgraded >version of the KH-11 [i.e. the KH-12? not clear]. The "better means to transmit its images to US military field units at sea or in such places as West Germany" (under the TENCAP programme) and the "greater maneuvering capability" were both advertised properties of the KH-12, so it probably is a KH-12. The name Strategic Response System is new to me though. > This bird is at a lower > altitude than the Lacrosse launched last year, and was deployed using the > arm, which Lacrosse wasn't. Article in fact says it was other way round. Interestingly, AW&ST says 1988 Titan 34D launch from VAFB might have carried a KH 11, echoing the recent posting from John Pike. This was the one originally labelled as an SDS, though AW&ST had no item on it at all as far as I know. >"Where is D.D. Harriman now, | Henry Spencer at U of Toronto Zoology >when we really *need* him?" | uunet!attcan!utzoo!henry henry@zoo.toronto.edu OK. So I'm ignorant. Who is D.D. Harriman? Meanwhile, I was beginning to believe that Henry's summaries might be the on-line version of AW&ST mentioned in "2010" when I noticed a recent ad therein, which says the whole text is available on line to suitably rich subscribers. Same goes for some other McGraw Hill trade journals. Nick -- Nick Watkins, Space & Plasma Physics Group, School of Mathematical & Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND JANET: nickw@syma.sussex.ac.uk BITNET: nickw%syma.sussex.ac.uk@uk.ac ------------------------------ Date: 27 Sep 89 17:43:09 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: Risk of NOT launching Galileo In article <205@cfa.HARVARD.EDU> willner@cfa.HARVARD.EDU (Steve Willner) writes: >From article <14737@bfmny0.UU.NET>, by tneff@bfmny0.UU.NET (Tom Neff): >> It's a nice point that scratching Galileo could cost us weather >> knowledge, but Mission To Earth will do it better. > >Are you sure? Presumably the same basic physics govern the weather >systems on the two planets, but the conditions are utterly different. >The way to verify models - which is all we have - is to test them on >systems that are as different as possible. Thus I expect that we will >learn things by studying Jupiter's weather that we would never learn by >studying only Earth's. Certainly there is considerable _risk_ that this >is true. This and another followup suggest we'll learn things from Jupiter's weather that we can't learn by studying our own. Granted. But this was not quite the issue. Will we learn materially more about OUR OWN weather from studying Jupiter than we can from studying Earth? I have my doubts. And if I have my doubts, you can bet that any Congressman who has heard of "Mission to Earth" would have his. I would appreciate hearing from actual atmospheric scientist who can point to an open meteorological conjecture for which Galileo looks more promising than Mission to Earth. For what it's worth I do want Galileo to go, but bogus justifications can come back to haunt us, as the Space Shuttle ("it'll cut costs to orbit by a factor of 10") demonstrates. -- "NASA Selects Deck Chair Arrangement For Space \_/ Tom Neff Station Titanic" -- press release 89-7654 \_/ tneff@bfmny0.UU.NET ------------------------------ Date: 27 Sep 89 19:21:23 GMT From: nolan@tut.cis.ohio-state.edu (Michael C Nolan) Subject: Re: Time Urgent: Voyager movies Oct 2 on satellite or tape In article HIGGINS@FNAL.BITNET (Bill Higgins-- Beam Jockey) writes: >Here's a press release I just received from JPL: >The recently completed Neptune Encounter Highlights tape will be transmitted >over NASA-Select on Monday, October 2. > >DATE/TIME: > >October 2 1:00-1:29 PM Eastern Time, 9:00-9:29 AM Pacific Time ^^^^^^^^^ ^^^^^^^^^ Um, These are not at the same time. Anybody know which one is right? -Mike mnolan@hindmost.lpl.arizona.edu nolan@arizjvax.bitnet ------------------------------ Date: Wed, 27 Sep 89 14:58:05 PDT From: Peter Scott Subject: Re: Mars Mission ship design In article <842@gtisqr.UUCP> kevin@gtisqr.UUCP (Kevin Bagley) writes: > 2) Anybody know the estimated mass of Freedom. Using Lunar gravity > assist, how much fuel/thrust would be needed. Don't forget the > return home requirements. A figure I have seen for "mass of assembly consumables", whatever *that* is, is 40,978 lb. I have also seen a figure of cost-to-orbit of $3,000/lb in 1988 currency. Peter Scott (pjs@grouch.jpl.nasa.gov) ------------------------------ Date: 27 Sep 89 15:05:42 GMT From: usc!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!jpl-devvax!leem@apple.com (Lee Mellinger) Subject: Re: Risk of NOT launching Galileo In article <14737@bfmny0.UU.NET> tneff@bfmny0.UU.NET (Tom Neff) writes: :It's a nice point that scratching Galileo could cost us weather :knowledge, but Mission To Earth will do it better. :-- Not necessarily true, Jupiter and the other planets with atmoshperes, give us data points on atmospheres that cannot be gotten any other way, the conditions are different, allowing the comparison of models to test the underlying assumptions. In fact, the planetary exploration program has spawned an entirely new academic discpline, Comparative Planetology. Lee |Lee F. Mellinger Caltech/Jet Propulsion Laboratory - NASA |4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516 FTS 977-0516 |{ames!cit-vax,}!elroy!jpl-devvax!leem leem@jpl-devvax.JPL.NASA.GOV ------------------------------ Date: 27 Sep 89 15:48:34 GMT From: rochester!dietz@rutgers.edu (Paul Dietz) Subject: Re: NIMF proposal from Martin Marietta In article <9681@chinet.chi.il.us> price@chinet.chi.il.us (Doug Price) writes: > >I talked to Zubrin at the Space Development Conference about the level of >radioactivly that could be expected in the NIMF reactor at its return to earth >orbit, and he said basically that the reactor operates for such a short >period over its entire life that its total residual radioactivity amounts ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >to the tens of curies. The worst case scenario of an uncontrolled burn-up >in earth's atmosphere after one or more Martian missions would be trivial >(though, of course, there are plenty of people out there that would find >this concept horrific as well.) How is total residual radioactivity defined? Plugging in numbers from the graph in Segre (Nuclei and Particles, 2nd ed., page 594), the energy (as beta or gamma rays) produced by fission products, per joule of heat produced at the time of fission, is roughly Time since fission watts/joule ----------------------------------- 1 day 1.5e-8 10 days 1.0e-9 100 days 5.0e-11 900 days 5.0e-12 Operating the reactor for ten minutes at 1000 MW(thermal) produces 6e11 joules of heat, so residual heat at 1, 10, 100 and 900 days is roughly 9 kW, .6 kW, 30 W and 3 W, respectively. At 1 MeV/decay (say), 3 watts is about 170 curies. NERVA with ET propellant production sounds ideal for asteroid retrieval to earth orbit -- lots of thrust if you have the volatiles, and it could insert into earth orbit without aerocapture. The reactor could also serve as a heat source to cook volatiles out of the asteroids. I have a hard time understanding this Mars fixation. There are lots of smaller planetoids closer to Earth, without deep gravity wells. Let's visit some of them first. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: Wed, 27 Sep 89 10:13:36 PDT From: Peter Scott Subject: YAHSS (Yet Another Henry Spencer Signature) jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) writes: >"Where is D.D. Harriman now >when we really *need* him?" Hmm... has anyone tried pitching the commercial space program to Donald Trump? I was just in Manhattan and visited Trump Tower. It's obvious the guy isn't afraid to spend money... ah, I can see it now... the *real* "Trump Shuttle"... Peter Scott (pjs@grouch.jpl.nasa.gov) ------------------------------ Date: 27 Sep 89 08:30:14 GMT From: mcsun!ukc!edcastle!erci18@uunet.uu.net (A J Cunningham) Subject: Re: Plutonium in space (was Risk of NOT launching Galileo) Greenpeace did an article in their newsletter which showed the location of all lost nuclear reactors and warheads in the world's oceans. There are about fifteen in all including a hydrogen bomb that rolled off the deck of an aircraft carrier off Japan. Given that most of the world's plutonium is in the hands of the military and the odds of a B52 crashing and spraying plutonium all over the ground (as one did in Spain when it collided with its tanker aircraft) are far greater than any accident involving a space mission (Are bombs built to withstand crashing better than RTGs?) surely this would be a better subject for lawsuits and column inches in the newspapers? Tony "Furthur!" ------------------------------ Date: 28 Sep 89 03:33:13 GMT From: ibmpa!szabonj@uunet.uu.net (nick szabo) Subject: Re: Alternative Space Goals, Anyone? (was Re: SpaceCause) In article <1989Sep13.013741.10776@cs.rochester.edu> yamauchi@cs.rochester.edu.U UCP (Brian Yamauchi) writes: >In article <2074@ibmpa.UUCP> szabonj@ibmpa.UUCP (Nick Szabo) writes: >>In article <9518@pucc.Princeton.EDU> EWTILENI@pucc.Princeton.EDU w rites: >>>The closest thing to that (if you don't have NSS' position statements) >>>That is to say, SPACE STATION, >>>MOON, and MARS are the three main goals. >> >>Ah, The Plan. >[What alternatives do we have to The Plan?] >More funding for robotic space probes would definitely help both space >science and space exploration, I quite strongly agree with this. We also need funding for basic R&D to create working models of MPD engines, laser propulsion, optical space communications, nuclear electric power, etc. BTW Henry those are just examples not necessarily the most important ones. :-) > and companies like AMROC, SSI, and >OSC/Hercules seem to be on the right track towards providing low-cost >access to orbit. > >These are important first steps, but what's next in the Alternative >Agenda for space development? Who knows? The purpose of the first step is to _explore_ the diverse range of possibilities. Some will turn up empty, and some will bring riches. We can't predict that now, so it is not only useless, it is damaging, to plan for it. We can _speculate_, however. Here is my favorite: we discover concentrated ores of rare but valuable isotopes on Io, the most differentiated body so far discovered in the solar system. We bypass the Moon and Mars altogether, creating the first permanent human space settlement around Jupiter. We use tethers on Metis to draw terrawatts of power* for industrial uses (including the tricky mining operations on Io!). We steer asteroids from the Main Belt into orbit around Jupiter, and use Metis power to build habitat structures. Of course this is far fetched. It is quite different than The Plan, and thus a heresy. But not one proponent of The Plan can demonstrate that this scenario is any less probable or useful than the Moonbase/Mars scenario. My own guess is that comets and asteroids are the most useful, followed by the Galilean system and Mars, with the Moon being a mere import-dependent tourist trap. But none of us have enough information to try to decide this now. "Anyone who attempts to generate random numbers by deterministic means is, of course, living in a state of sin." John von Neumann * Metis orbital power proposal due to Paul Dietz. The idea is to use tethers to extract the power of a tiny portion of Metis' orbital velocity through Jupiter's very large magnetic field. -- -------------------------------------------- Nick Szabo uunet!ibmsupt!szabonj These opinions are not related to Big Blue's ------------------------------ End of SPACE Digest V10 #103 *******************