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, 10 Oct 89 04:22:59 -0400 (EDT) Message-ID: <0ZAOPAm00VcJMNz04P@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 10 Oct 89 04:22:37 -0400 (EDT) Subject: SPACE Digest V10 #131 SPACE Digest Volume 10 : Issue 131 Today's Topics: Re: Shuttle-Centaur Re: Ozone ( was Re: NASA Headline News for 09/29/89 ) RE: Re: Concord, Nasp, shuttle Re: Shuttle-Centaur astrodynamic software Re: Galileo Jovian atmospheric probe -- is it sterilized??? Re: RTGs, shuttle launch risks RE: Happy Birthday, Robert Goddard and Konstantin Tsilkovsky. Orbital Rendezvous (was Re: Shuttle-Centaur) BioSphere II Re: Happy Birthday, Robert Goddard and Konstantin Tsilkovsky. ---------------------------------------------------------------------- Date: 8 Oct 89 02:26:21 GMT From: attcan!utgpu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Shuttle-Centaur In article <1064@m3.mfci.UUCP> rodman@mfci.UUCP (Paul Rodman) writes: >>>I heard the original plan had DUMP VALVES for the Centaur fuel... >>Yup. Most airliners with significant problems will dump fuel before landing >>as well, for much the same reasons... What's the big deal? >... > - An airliner dumps JP4. I presume the Centaur dumps potent fuel > + oxidizer (not hypergolic I trust!). What is the probability > of ignition in the presence of RCS thrusters, hot airframes, > SRBs... Centaur would be dumping liquid hydrogen and liquid oxygen. Oxygen doesn't ignite. Hydrogen can be treated much like JP4, despite some of the scare stories you see in the media. (Incidentally, JP4 is military jet fuel; an airliner would be dumping something like Jet A.) No, they're not hypergolic. Dumping would probably be done late in the abort, at a time when the SRBs are gone and the RCS thrusters are not useful. Ignition doesn't seem too likely, and I wouldn't think it would be automatically disastrous even if it did happen. > - You are awfully busy on a launch abort, are you going to > allow a computer to decide when to dump? Yech. The decision would undoubtedly be manual. Most of the nasty decision-making is early in the abort (engine problems, trajectory) or very late (landing); dumping would probably be done in between, in glide. >I'm not saying it can't (or shouldn't) be done, it just seems like >more dicey scenerios are added to an already hazardous activity... The orbiters are very safe sitting on the ground. Getting results requires taking risks. >... Seems like the correct approach >would be to have a Space tug (+ IUS on the probe too) to kick things >out of earth orbit. Refuel the tug from unmanned tankers, please. This would undoubtedly be the correct approach. There is a small problem: the Tug died long ago and was not available. Centaur was. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 8 Oct 89 01:54:56 GMT From: attcan!utgpu!utzoo!henry@uunet.uu.net (Henry Spencer) Subject: Re: Ozone ( was Re: NASA Headline News for 09/29/89 ) In article <233@unicorn.WWU.EDU> n8735053@unicorn.WWU.EDU (Iain Davidson) writes: >He told me , beleive it or not, that the ozone/world would "fix/correct" > itself over time. This is due to the supply of Algae in the world's > ocean-- The supply will increase if the hole grows bigger, and increase > production of what's needed for repairing the hole... I think either he or you has confused the ozone hole (lack of ozone over Antarctica) with the greenhouse effect (excess CO2 worldwide). There are no algae in Antarctica to react to the ozone hole, and their most probable reaction to it would be death, which won't help. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Thu, 5 Oct 89 16:51:35 PDT From: rrk@jupiter.risc.com (Richard Killion) Subject: RE: Re: Concord, Nasp, shuttle Cc: rrk@risc.com >In article <5286@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes: >>It's not clear to me that SSTs will ever be economical >>forms of transport. prism!ccsupos@gatech.edu (Olivier Schreiber of Georgia Institute of Technology) then responds: >Indeed, it may not do a businessman any good to shave a >few hours of flight time off his schedule if he spends >two hours in urban traffic >to get in and out of the airports of departure and >destination. ---- The best time for getting from L.A. to Tokyo is about 10 hours (let's add 2 hours on both sides for traffic to get to 14 hours). As a traveller to Tokyo, I know that a 6 hour flight is a big difference compared to 14! I don't consider the extra 8 hours to be a *few hours* and could do without them. Tokyo is CLOSE, compared to most of the Pacific Rim countries. There are longer flights such as to Australia or the ASEAN countries. The urban traffic time is just minor overhead. ------------------------------ Date: 7 Oct 89 20:24:03 GMT From: telesoft!roger@ucsd.edu (Roger Arnold @prodigal) Subject: Re: Shuttle-Centaur doom@portia.Stanford.EDU (Joseph Brenner) writes: > So what was the problem with launching the Centaur dry and fueling > it up in orbit? > [..] > (My guess: You've got to boost the fuel somehow, and putting it in > a different shuttle launch just moves the risk to another time. > Boosting the fuel with an unmanned rocket might work but in > those days NASA's policy was to do everything with the shuttle. > Also, this gets back to the rendevous in orbit issue, which > I gather is considered too tough by NASA, despite experience with > Gemini, Apollo, Skylab and Apollo/Soyuz.) > > -- Joe B. One method that was proposed was to fuel it from residual fuel in the ET. (It's just as easy to carry the needed mass of Centaur fuel in the ET as in the Shuttle, since the ET can go all the way to orbit with the Shuttle, with a slight gain in net payload over the launch path that causes the ET to reenter in the Indian Ocean). Problems: 1) It's not easy to transfer liquid fuels in microgravity. To be able to scavange fuel from the ET, it would probably have been necessary to add an LH2/LOX thruster to the Shuttle, and keep Shuttle & ET under continuous low acceleration during the fuel transfer period. This was too radical a development for NASA, even though it would have meant increased Shuttle payload. 2) It would have left the ET in LEO. Horrors! Poor little NASA couldn't see its way to develop the systems needed to prevent an uncontrolled ET reentry as its orbit decayed. In the two+ year hiatus following the Challenger accident, and for the same money spent, the NASA of the 60's could probably have developed the unmanned Shuttle-C, making the safety issues of a Shuttle Centaur irrelevant. (And, incidently, restoring a Saturn class heavy launch capability.) The NASA of the 80's... No, I won't say it. I'm letting my disillusionment get the best of me. I HATE whining. - Roger Arnold ucsd!telesoft!roger ------------------------------ Date: 8 Oct 89 08:12:49 GMT From: lightsabre!kenobi@sun.com (Rick Kwan) Subject: astrodynamic software I have been toying off-and-on with computational astrodynamics for several years. It's "on" time again... so I thought I'd throw some questions to those of you with better stamina for such things: -- Is there any well-accepted public domain source code for handling multi-body problems (like several planets orbiting a star)? (What do universities do for this?) -- Is there a standard machine-parsable ephemeris format for interplantary missions? My assumption is that the same format might apply both to planets and to spacecraft. -- Any recent books on astrodynamics? All my stuff dates back to the mid-70s or earlier. (I assume the principles haven't changed; but there's been a tendency lately to use computer programs to illustrate problem solutions. With the latest emphases on "scientific visualization," I expect this even more.) -- Has anyone taken RAND Corp.'s ROCKET program and recoded into C? ;-) Rick Kwan Sun Microsystems - Intercontinental Operations kenobi@sun.UUCP or kenobi%lightsabre@sun.COM Rick Kwan (aka Obi-Kwan Kenobi) Sun Microsystems - Intercontinental Operations kenobi@sun.UUCP or kenobi%lightsabre@sun.COM ------------------------------ Date: 8 Oct 89 07:33:30 GMT From: agate!shelby!portia!hanauma!joe@ucbvax.Berkeley.EDU (Joe Dellinger) Subject: Re: Galileo Jovian atmospheric probe -- is it sterilized??? In article <2035@frog.UUCP> john@frog.UUCP (John Woods) writes: >Or do you somehow think that Earth life is so obviously superior to >anything Jupiter can crank out that Jovian life can't possibly >measure up? >-- >John Woods, Charles River Data Systems, Framingham MA 508-626-1101 >...!decvax!frog!john, john@frog.UUCP, ...!mit-eddie!jfw, jfw@eddie.mit.edu Well, I would tend to agree with you, but there are precedents to the contrary. South America is a much larger continent than North America, so you would expect it to be able to "hold its own" evolutionarily against invaders... and yet when the isthmus of Panama formed (quite recently geologically speaking) the North American mammals almost _immediately_ spread South and _totally wiped out_ all the native South American mammals. I know of only one South American mammal that managed to make the trip the other direction --- the Opossum. The problem was that South America, though possessing a large, diverse ecosystem, was still sticking with marsupials as the dominant type of mammal. In the fossil record there is a sudden spectacular explosion of diversity near the beginning of the paleozoic. What was Earth life doing for the first few billion years of life (MOST of the history of life) when "not much" appears to have been happening? My guess is it was meta-evolving: evolution towards genetic systems that are able to evolve more efficiently. For example, the genetic code is arranged in such a way that point mutations tend to change one amino acid for a chemically similar one. (Evolution is then more like a "gradient search" algorithm instead of a "monkey attempting to write Hamlet" one.) To give some idea about just how efficient evolution on Earth has become, the EYE, far from being a lucky miracle of evolution, appears to have evolved AT LEAST TWICE, independently, complete with retina, iris, lens, etc! The best guess is that the last common ancestor between humans and the Octopus preceded the evolution of the eye by a wide margin, and yet the Octopus possesses an eye very similar to our own in form and function. This might be taken as evidence against evolution, but biological evidence supports the notion it really WAS independently evolved. When you look at all the "technical specifications" the octopus eye is very different, while all vertebrates' eyes are essentially the same. From the geological record, it appears that the HARD part was coming up with multi-cellular life. After that, EVERYTHING else - shells, nervous systems, 4-chambered hearts, large brains --- is trivial. While life per se may be common, I suspect Earth life got lucky and evolved a system that permitted especially efficient evolution. That's why we're here launching space probes against them, instead of vice versa. \ /\ /\ /\/\/\/\/\/\/\.-.-.-.-.......___________ \ / \ / \ /Dept of Geophysics, Stanford University \/\/\.-.-....___ \/ \/ \/Joe Dellinger joe@hanauma.stanford.edu apple!hanauma!joe\/\.-._ ------------------------------ Date: 8 Oct 89 03:30:32 GMT From: portal!cup.portal.com!Jerome_V_Vollborn@uunet.uu.net Subject: Re: RTGs, shuttle launch risks While this is not particularly germane to this group, the average 1000 MW coal fired power plant costs 51 people their lives. Most of those are transportation workers (rail road people) killed while transporting the coal and ash. These numbers do not reflect any early deaths from stack gases or heavy metals leaching from the ash piles. BTW hydroelectric plants are not free from risks either. Thirty years ago the dam at Vionia (sp?), Italy, failed and killed 20 000 people by flushing the village off of the face of the opposite hill. The number is approximate because few of the bodies were recovered. Jerome Vollborn ------------------------------ Date: Sun, 8 Oct 89 11:41:27 CDT From: sedspace@doc.cc.utexas.edu (abrams) Posted-Date: Sun, 8 Oct 89 11:41:27 CDT Subject: RE: Happy Birthday, Robert Goddard and Konstantin Tsilkovsky. In Space Digest #124, Larry Klaes sends >On October 4, 1857, Konstantin Tsilkovsky, >the Soviet founder of modern rocketry, was born exactly one hundred >years to the day when SPUTNIK 1 was launched. Asimov's Biographical Encyclopedia of Science and Technology lists Tsiolkovskii's birthday as September 17, 1857 and Asimov even mentions that 100 year anniversary launching being late. I'm not saying Larry is wrong...but someone is. Any other sources out there? Steve Abrams sedspace@walt.cc.utexas.edu "Mankind will not remain tied to Earth forever" -- Tsiolkovskii's tombstone (not as poetic as the "cradle" interpretation, but closer to being a transliteration) ------------------------------ Date: 8 Oct 89 18:49:11 GMT From: rochester!yamauchi@pt.cs.cmu.edu (Brian Yamauchi) Subject: Orbital Rendezvous (was Re: Shuttle-Centaur) In article <5604@portia.Stanford.EDU> doom@portia.Stanford.EDU (Joseph Brenner) writes: >Also, this gets back to the rendevous in orbit issue, which >I gather is considered too tough by NASA, despite experience with >Gemini, Apollo, Skylab and Apollo/Soyuz.) Really? Why does NASA think orbital rendezvous is so difficult? A shuttle already accomplished this to recover a satellite. Besides, how do they plan to build Freedom without being able to rendezvous in orbit? _______________________________________________________________________________ Brian Yamauchi University of Rochester yamauchi@cs.rochester.edu Computer Science Department _______________________________________________________________________________ ------------------------------ Date: Sun, 8 Oct 89 18:33 EST From: Subject: BioSphere II Has anyone heard anything lately about the Arizona (?) BioSphere II project? I believe they were to have entered by now. Are they surviving? Any major/minor environmental problems? I still think that this project is one of the most exciting ongoing experiments being carried out at this time. Its effects on long-term survival in closed systems (i.e. space) will hopefully be phenomenal. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Arnold Gill | | Queen's University at Kingston | | BITNET: gill@qucdnast | | INTERNET: gill@qucdnast.queensu.ca | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- ------------------------------ Date: 9 Oct 89 02:42:20 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: Happy Birthday, Robert Goddard and Konstantin Tsilkovsky. In article <8910081641.AA12063@doc.cc.utexas.edu> sedspace@DOC.CC.UTEXAS.EDU (abrams) writes: >>On October 4, 1857, Konstantin Tsilkovsky, >>the Soviet founder of modern rocketry, was born... >Asimov's Biographical Encyclopedia of Science and Technology lists >Tsiolkovskii's birthday as September 17, 1857 and Asimov even mentions >that 100 year anniversary launching being late... Be careful. The dates are slippery. Russia was on the old Julian calendar well into the 20th century; the switch to the modern Gregorian calendar was much more recent than we're used to. The Soviets also tend to cite dates as if the switch had been considerably earlier, which adds to the confusion. This is why the anniversary of the "October Revolution" is celebrated in November. I thought to hit Willy Ley's "Rockets, Missiles, and Men in Space" for a check. (This is THE BEST history of the early space age, written by someone who was there for most of it. In particular, he knew and corresponded with Tsiolkovsky.) Ley cites Tsiolkovsky's birthday as 5 Sept 1857 Julian, 17 Sept Gregorian. He says that it was widely reported in the West that the first launch attempt for Sputnik would be made on the anniversary of Tsiolkovsky's birth, but nothing visible happened that day. Incidentally, there is no one-to-one mapping from Cyrillic characters to Latin ones, and so there is some debate about the spelling of Tsiolkovsky's name. He himself spelled it "Ziolkovsky" when writing in Latin-alphabet languages, according to Ley, although "Tsiolkovskii" is a more phonetic rendering. -- A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology megabyte of flaming. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ End of SPACE Digest V10 #131 *******************