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/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Thu, 19 Apr 90 02:23:07 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 19 Apr 90 02:22:16 -0400 (EDT) Subject: SPACE Digest V11 #286 SPACE Digest Volume 11 : Issue 286 Today's Topics: Re: Interstellar travel Re: Apollo 13, STS-1, Vostok 1 anniversaries Re: Questions about the Voyagers NASA Headline News for 04/18/90 [Afternoon] (Forwarded) Re: Pegasus launch from Valkyrie (or ... Materials (Was: Re: Energy consumption) Re: space news from March 12 AW&ST etc. Re: Fermi Paradox ---------------------------------------------------------------------- Date: 18 Apr 90 18:33:13 GMT From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Interstellar travel In article dlbres10@pc.usl.edu (Fraering Philip) writes: >I don't have references, but studies on Interstellar travel have looked >at the possibility of using a dust or gas cloud put in front of you while you >are coasting to cut down on the amount of gas or dust likely to collide >with you. Maintaining such a cloud during the long cruise phase is costly in mass. Project Daedalus just used armor on the front for cruise, but did in fact use a smoke cloud for the actual encounter with the target solar system. Solar systems are very dusty places at 15% of the speed of light... -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 18 Apr 90 17:37:16 GMT From: hplabsb!dsmith@hplabs.hp.com (David Smith) Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries In article <36043@cci632.UUCP> dvh@cci632.UUCP (David Hallidy) writes: >the Service Module exploded, causing them to have to limp around the >Moon and back to Earth, using the Oxygen on board the Lunar Lander >and an ingenious fabrication of some sort using Lithium Hydroxide, which >was on board, to give them the Oxygen they needed for the return. The lithium hydroxide was for removing carbon dioxide from the air. The lunar module did not have enough cartridges for the time it would take to get back, and naturally ;-) the cartridges for command and lunar modules were incompatible. So they adapted the CM cartridges to the LM with duct tape. -- David R. Smith, HP Labs | "It is said that St. Patrick drove the dsmith@hplabs.hp.com | snakes out of Ireland. They were last seen (415) 857-7898 | selling junk bonds." -- Johnny Carson ------------------------------ Date: 18 Apr 90 20:53:37 GMT From: usc!brutus.cs.uiuc.edu!ux1.cso.uiuc.edu!sp20.csrd.uiuc.edu!davies@ucsd.edu (James R. B. Davies) Subject: Re: Questions about the Voyagers In article <1990Apr18.185031.25212@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: |> In article <1990Apr18.023225.15856@cs.uoregon.edu> solana@spencer.cs.uoregon.edu (David Solana) writes: |> |> > * Why didn't they visit Pluto? ... |> |> Because it was nowhere near their flight paths, which were fixed by the |> use of gravity-assist maneuvers from planets further in. |> One of the Voyager mission planners gave a talk here recently. He said that Voyager 1 could have gone on to Pluto after Saturn (and some of the ground crew wanted it to, including the speaker), but to do so would have meant omitting the close fly-by of Saturn's moon Titan. To go on to Pluto from Saturn, a gravity assist from Saturn would have been possible. Titan was on the wrong side, so they couldn't do both. At the time Titan was considered to be a good candidate for the most interesting body in the solar system (other than Earth, of course) since it was known to have an atmosphere, wasn't a gas giant, etc. In fact, it turned out to be relatively bland and featureless. Another factor in the decision was that the trip to Pluto would have been quite long, and the Voyager might not have lasted that long. ------------------------------ Date: 18 Apr 90 21:32:41 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 04/18/90 [Afternoon] (Forwarded) ----------------------------------------------------------------- Wednesday, April 18, 1990 Audio Service: 202/755-1788 ----------------------------------------------------------------- This is a 1:00 p.m. update of NASA Headline News for Wednesday, April 18.... Space shuttle managers have announced the target date for the launch of the STS-31 space shuttle mission has been advanced one day to Tuesday, April 24. The launch opportunity period on the 24th will begin at 8:31 a.m., EDT. * * Controllers at Jet Propulsion Laboratory report all subsystems are operating satisfactorily aboard the Venus-bound Magellan spacecraft. It's traveling at a velocity of over 35-thousand miles per hour relative to the planet and now is just 34 million miles away. An attitude reference test was successfully completed last week, star calibrations have gone well and two Deep Space Network checks have been successful. * * Meanwhile, the Galileo spacecraft is operating extremely well. The first four-day portion of a complicated trajectory maneuver was completed last week. The second part of the maneuver is scheduled for mid-May. Several more corrections will be made before the spacecraft's gravity assist flyby of Earth in early December. * * Scientists are puzzled with some data from the Cosmic Background Explorer Satellite launched last November, but also pleased with a visual byproduct. Wire service reports say scientists meeting in Washington, D.C., are confounded by data which indicate an unexpectedly smooth and uniform expansion of the universe and no indication of other cataclysmic events that had been theorized. Michael Hauser, of NASA's Goddard Space Flight Center says, "The quandry is deepening". A color image of the galactic center of the Milky Way was released yesterday free of cosmic dust that has obscured our galaxy's center previously. * * President Bush was criticized yesterday by some western European delegates to a White House conference on global warming for not taking a stronger stand on the issue. The President has called for more data before taking drastic control efforts which could have serious effects on the world economy. _________________________________________________________________ Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are EDT. Thursday, April 19..... 11:30 a.m. NASA Update will be transmitted. Friday, April 20.... 10:30 a.m. STS-35 astronaut news conference from Johnson Space Center. Sunday, April 22..... 1:00 p.m. STS-31 crew arrival at KSC Monday, April 23..... 9:00 a.m. STS-31 Countdown Status Report 10:00 a.m. APU/telescope Status Report 11:00 a.m. Prelaunch News Conference Tuesday, April 24...... 4:00 a.m. STS-31 mission launch coverage begins. NOTE: During the STS-31 mission television highlights will be transmitted on Satcom F1R, transponder #13 at 12 midnight, EDT, for the benefits of TV stations and educational institutions in Alaska and Hawaii. All events and times are subject to change without notice. ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, EDT. ----------------------------------------------------------------- A service of the Internal Communications Branch, NASA Hq. ------------------------------ Date: 18 Apr 90 18:54:44 GMT From: pasteur!helios.ee.lbl.gov!hellgate.utah.edu!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: Pegasus launch from Valkyrie (or ... In article <8911@pt.cs.cmu.edu> vac@sam.cs.cmu.edu (Vincent Cate) writes: >How about the concord? Concorde, please. Not impossible, but Concorde is not built for dropping things, and it would take quite a bit of work to fit it for the job and test things out properly. (Proper separation of a dropped object at supersonic speed is not to be taken for granted -- fighter designers work fairly hard on this and test it at great length.) A more fundamental problem is that it's an expensive bird to operate -- the current ones make money (yes, they do, they were subsidized once but not any more) only by having very high fares -- and none of the existing ones is for sale. -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 18 Apr 90 06:50:15 GMT From: agate!earthquake.Berkeley.EDU!gwh@ucbvax.Berkeley.EDU (George William Herbert) Subject: Materials (Was: Re: Energy consumption) In article <1990Apr17.191124.22668@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: > >That's not what he said. In any case, many newer space vehicles probably >*will* use old alloys. Hermes will be mostly aluminum, for example, not >titanium like the shuttle. The fact is, tried and true alloys are quite >adequate for spaceflight unless you are pushing the state of the art for >its own sake, e.g. NASP. Umm, Henry, did'ja look before this posting? :-) [sorry] The shuttle is good ole Aluminum alloys, much of it garden variety 2024 and 7075 ... Which is not to detract from the general tone of your posting, which was that the shuttle pushed technology all over. It did, in almost all ways, and in retrospect building it out of titanium would have been a great idea because it would have ended up a lot lighter with a corresponding higher payload, all for a fraction of the total development cost...an example of bad early design economics failure. ******************************************************************************* George William Herbert JOAT For Hire: Anything, Anywhere: My Price UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-) ------------------------------------------------------------------------------- "Who?" the man managed. Whip me, Beat Me, Make me learn C... "The Rastafarian Navy," Case said, ++++++++++ gwh@ocf.berkeley.edu OR "...and all we want is a jack into your ========== gwh@soda.berkeley.edu OR custodial system." -neuromancer """""""" maniac@garnet.berkeley.edu ------------------------------ Date: 18 Apr 90 17:05:34 GMT From: zaphod.mps.ohio-state.edu!rpi!brutus.cs.uiuc.edu!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: space news from March 12 AW&ST etc. In article <9639@cbnewsh.ATT.COM> mrb1@cbnewsh.ATT.COM (maurice.r.baker) writes: >> Soviets say that the first Buran orbiter probably will not fly again, > >Does anyone know how many orbiters there are in the USSR shuttle "fleet"? >Is this really saying that there is a new orbiter design under construction >now... There is at least one more under construction. Reports vary on the eventual total size of the fleet, probably because they aren't sure yet. -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 18 Apr 90 18:58:05 GMT From: pasteur!helios.ee.lbl.gov!hellgate.utah.edu!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucbvax.Berkeley.EDU (Henry Spencer) Subject: Re: Fermi Paradox In article <1990Apr18.013321.1778@mentor.com> mbutts@mentor.com (Mike Butts) writes: >On the subject of relative time, go read "Dragon's Egg" by Dr. Robert Forward. >Intelligent life evolves on the surface of a neutron star, based on nuclear >chemistry, not that lazy, slow, electron-shell stuff we use. They live about >10^6 times faster than we do. It's a great read, and backed up quantitatively >in the appendix. In this context it's an instructive example on how alien >other life forms might be... Actually, Forward himself admits that his neutronic life wouldn't work. The "plants" that are the base of the food chain supposedly run on the temperature difference between the crust and the sky, and he says that thermodynamically this doesn't work well enough to fuel neutronic life. I agree that it's a good book and relevant too. -- With features like this, | Henry Spencer at U of Toronto Zoology who needs bugs? | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ End of SPACE Digest V11 #286 *******************