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, 26 Apr 90 02:53:23 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 26 Apr 90 02:52:52 -0400 (EDT) Subject: SPACE Digest V11 #320 SPACE Digest Volume 11 : Issue 320 Today's Topics: Human brain power (was Fermi paradox) Re: Dyson spheres? Re: SETI Re: Need info on Space Stations Re: Power grid frequency Re: Apollo 13, STS-1, Vostok 1 anniversaries Re: Re: Dyson spheres, heat flow Re: Power grid frequency STS31 Launch Hold At T-31 Seconds Space Shuttle history/mission profile/dimensions Re: Decompression Re: Galileo Update - 04/17/90 Re: Pegasus launch is a success! ---------------------------------------------------------------------- Date: Wed, 25 Apr 90 14:33:50 EST From: JC%RMC.BITNET@vma.cc.cmu.edu Subject: Human brain power (was Fermi paradox) In SPACE_Digest V11 #298, greer%utdssa.dnet%utadnx@utspan.span.nasa.gov writes: > Maybe the human brain can't create something smarter than itself. There are those who believe that if the brain was simple enough to understand itself, it would be too simple to understand itself. John Coughlin Net: JC@RMC.BITNET Vox: 613-541-6439 Fax: 613-547-3053 ------------------------------ Date: 26 Apr 90 01:30:31 GMT From: thorin!homer!leech@mcnc.org (Jonathan Leech) Subject: Re: Dyson spheres? In article <1990Apr25.191404.9898@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >Better would be to use absorbing sails (make them out of doped silicon and >you've solved your power problems too!), which only give half as much thrust >but don't have this particular problem. Well, don't have it so badly, at >any rate, given suitable coatings etc to reduce infrared re-emission inward. Or use conical sails which don't reflect light back at the primary. Admittedly larger sails would be needed since a lot of radial thrust would be lost, and the issue of toasting other habitats might arise, so placement would be more important. -- Jon Leech (leech@cs.unc.edu) __@/ ``You're everything I ever wanted in a human AND an extraterrestrial.'' - Dr. Steve Mills in _My Stepmother is an Alien_ ------------------------------ Date: 26 Apr 90 04:21:48 GMT From: well!avery@apple.com (Avery Ray Colter) Subject: Re: SETI steve@nuchat.UUCP (Steve Nuchia) writes: >At one of my clients' offices there is a small poster, apparently >once part of a magazine ad. It is a picture looking across a >mountain valley from the top of a very high, very rocky slope, >looking over the handlebars of a motorcycle. The caption: > "Never rule anything out." Or, as my former roommate, a mountain bike racer in the team called FAT (Finish Alive Team) would say: FAT FACT #1: The fastest way to accelerate: DESCEND WITH CONVICTION! ----------------------- -- Avery Ray Colter Internet: avery@well.sf.ca.us | {apple|hplabs}!well!avery o/~ Mama, mama, mama, keep those skinny girls at home, o/~ `Cause this skinny boy wants a BIG FAT BLONDE! - The Rainmakers ------------------------------ Date: 24 Apr 90 11:17:59 GMT From: zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Mark.Perew@tut.cis.ohio-state.edu (Mark Perew) Subject: Re: Need info on Space Stations Doesn't the "habitable volume" of an orbiter depend on the positioning of the airlock? If the airlock is mounted in the middeck it reduces the "habitable volume" from what it would be if the airlock were mounted in the cargo bay. -- Mark Perew ...!{dhw68k,zardoz,lawnet,conexch}!ofa123!Mark.Perew Mark.Perew@ofa123.FIDONET.ORG 714 544-0934 2400/1200/300 ------------------------------ Date: 25 Apr 90 16:30:14 GMT From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!aristotle!pjs@tut.cis.ohio-state.edu (Peter Scott) Subject: Re: Power grid frequency I remember years ago reading that some ELINT satellites picked up interference on a frequency of 60Hz while over North America, which changed to 50Hz as they went over Europe... This is news. This is your | Peter Scott, NASA/JPL/Caltech brain on news. Any questions? | (pjs@aristotle.jpl.nasa.gov) ------------------------------ Date: 25 Apr 90 19:12:56 GMT From: concertina!fiddler@sun.com (Steve Hix) Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries In article <5903@ganymede.inmos.co.uk>, conor@wren.inmos.co.uk (Conor O'Neill) writes: > > Actually, "Ductape" is spelt "Gaffer Tape" in the UK. > I wonder who invented it first?... :-) Ductape != Gaffer Tape They look very similar, but use different adhesive backings. (Gaffer tape doesn't leave a sticky residue.) As for who was first... ------------ "Up the airey mountain, down the rushy glen, we daren't go a-hunting for fear of little men..." ('cause Fish and Game has taken to hiring axe-carrying dwarves) ------------------------------ Date: Wed, 25 Apr 90 16:18:50 EDT From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Re: Dyson spheres, heat flow >From: uokmax!spcoltri@apple.com (Steven P Coltrin) >Subject: Re: Dyson spheres, heat flow >In article <9004242137.AA02290@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >>Additional question: in "Ringworld", Larry Niven describes a cooling system >>for use in a spaceship near a star - since cooling by radiation is impractical, >>the waste heat is pumped to a collection point within the ship, from which it >>will be dispensed when the ship is no longer near a star. Could this work, and >>if so to what extent? I could make a guess, but that's all it would be. >That would depend on how good your heat sink and pump (and insulation) were... >and how much risks you want to take. I was perhaps thinking of fundamental limits imposed by the laws of thermodynamics. One plausible limit: if the power for your heat pump is derived from a heat engine, and if the system is closed, then waste heat storage will work only if the temperature of the storage location is kept below the temperature of the heat engine's heat source. >A better system occurred to me awhile ago; presuming the _Lying Bastard_ was >fusion-powered (I don't remember if it was ever stated, even), then the power >plant is going to be producing helium exhaust. Just pump your waste heat into >it and jettison. Comments? The reaction drives were fusion powered. Niven has been known to get numbers wrong, sometimes by several orders of magnitude. Even near a star, most of the sky is available for radiating heat, if you go about it the right way. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 26 Apr 90 03:03:18 GMT From: fernwood!portal!cup.portal.com!mmm@apple.com (Mark Robert Thorson) Subject: Re: Power grid frequency A long time ago, a friend of mine and I experimented in communication by driving an audio signal into the ground. I had read an article, in POPULAR ELECTRONICS, I think, about how this technique had been used before radio was invented. It involved driving an audio signal across two stakes (we used barbeque skewers) pushed into the ground, several feet apart. A similar setup about 50 feet away (but with the amplifier reversed) picked up the audio quite well. Then we tried doing it over a distance of a quarter of a mile or so. No luck. The 60 Hz hum drowned out everything else. The magazine article said there was a line running down Africa where the hum changes from 60 Hz of the Americas to the 50 Hz of Asia and Europe. . 1,$p ------------------------------ Date: 25 Apr 90 13:35:09 GMT From: techpubs@burdvax.prc.unisys.com (Technical Pub. Vince Short) Subject: STS31 Launch Hold At T-31 Seconds . Countdown will hold at T-31 seconds due to a failure. . . Its the LO2 outboard fill and drain valve. . . Its LPC MPS8 and PD9 outboard fill and drain closed power is off, it should be on. . . Recommendation? . . We're in a no-go situation, we should have open power and we do not, er, excuse me, closed power. . . And MPS can we verify that the valve is closed? . . Negative, we right now show an open position. We can not verify that the valve is closed. . . We have the closed power on and the open position off, we can try cycle one time and try to pick up the closed position but ah we don't think its closed power. . . OK and MPS we have a message that we were blocked by a prerequisite sequence DCL18. . . (Garbled) . . Ah, holding 2 minutes. . . We're going to make an attempt to pressure(?) that valve closed, we've got the (?) off, at this point we should be in good shape. . . I copy. Proceed. . . The valve is closed, we're go. . . OK and we're (?) going to pick up here in the terminal sequence, MPS? . . That's affirmative here, we're go, we're in good shape. . . OK you have a go to proceed. . . GLS pick up the count immediately. . . I copy. Mark. GLS is go for auto-sequence start. . . 25 . . . 20 . . . 15 . . . Go for main engine start . . T-6 . 5 . 4 . 3 . 2 . 1 . and liftoff. . . And NASA follows through with a picture perfect lift off and orbital insertion of Discovery and its HST cargo. So, can anyone out there interpret what was going on here? Was there a problem with the closure of the LOX fill and drain valve? Or was it a faulty indicator? Or was it "blocked by a prerequisite"? And if it was is that a software glitch or what? Anyone care to explain? . . The above was transcribed from a tape recording of the amateur radio rebroadcast of Shuttle audio from Goddard Space Flight Center. All acronyms are questionable and I tried to pick out the content from in between the statements by the announcer who kept speaking over the important communications. But perhaps it is good enough for someone who knows what's going on to explain it to the rest of us interrested observers. . . . . Joseph M. Fedock . . Technical Publications . . Unisys Corporation . . Defense Systems/EISG/VFO . . Paoli, PA 19301 . . (215) 648-2495 . . techpubs@burdvax.PRC.Unisys.COM . ------------------------------ Date: 26 Apr 90 01:03:18 GMT From: ucselx.sdsu.edu!petunia!news@ucsd.edu ( * * * Hunter * * * ) Subject: Space Shuttle history/mission profile/dimensions I'm doing a report on the space shuttle and I need the following information and I would be extremely thankful to anyone or group who could E-mail or post the following information to me by Sunday: * History of the shuttle program (brief) * Shuttle mission profile (times/events/altitude/speed/etc.) * Shuttle/STS dimensions (i.e. dimensions for the shuttle, ET, SRB and complete assembly) * Chronology of shuttle missions, with listings of mission accomplishments and dates, launch times, shuttle missions, etc. I know that this is a tremendous amount of information, but much of it is _extremely_ difficult to come by, such as an accutate chronology of the missions and a _precise_ mission profile. Thanks in advance, Mike. #=============================================================================# |\_/| mhuang@polyslo.CalPoly.EDU "PROGRAM: tr.v. To engage in a pastime {O o} mhuang@FubarSys.SLO.CA.US similar to banging ones' head against a ( " ) * Ack! Ack! Pfft! Ack! * wall, except with fewer chances for reward." U (Bill the Cat wants to get a space shuttle.) Admiral Michael "Hunter" Huang +---<<< * * * S T A R T R E K * * * >>>---+ USS Ticonderoga, NCC-1736 +--<<< * * * * L I V E S ! ! ! * * * * >>>--+ #=============================================================================# ------------------------------ Date: 25 Apr 90 18:16:42 GMT From: usc!elroy.jpl.nasa.gov!jpl-devvax!jenkins@ucsd.edu (Steve Jenkins) Subject: Re: Decompression In article <9004242223.AA02337@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >Apparently the lungs contain compound which forms a foam, which in turn keeps >the lung somewhat inflated even when you exhale. In certain medical conditions, >this substance is missing, causing the lungs to collapse. The foam limits the >degree to which you can exhale. I don't know what percentage of the total lung >capacity this foam takes up, but barring further information, it seems best to >just go ahead and keep your breathing passages open. The surface tension of the alveoli is such that the lung itself would collapse to near zero volume without external support. In vivo, at rest, the lungs maintain a mechanical equilibrium volume called Functional Residual Capacity (about 3 l in adults) by adhering (again by surface tension) to the chest wall. The lungs do produce a surfactant that raises the compliance, making them more distensible. It is not a foam. More to the point: Transport of oxygen from lungs to blood is almost entirely by diffusion. If the partial pressure of O2 in alveolar gas falls to zero, the arterial PO2 will rapidly fall below the minimum necessary for consciousness. After about 20 s of transport time from lungs to brain, you black out. Anyone who's ever (foolishly) taken a few deep breaths from a helium balloon knows how fast it happens. Holdling your breath to raise the PO2 will prolong consciousness; Doing it without damaging the lungs would be tricky. A good reference is the little book "Respiratory Physiology -- the essentials" by John B. West (Williams & Wilkins). -- Steve Jenkins N6UNI jenkins@jpl-devvax.jpl.nasa.gov Caltech/Jet Propulsion Laboratory (818) 354-0162 ------------------------------ Date: 25 Apr 90 20:38:59 GMT From: usc!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!IDA.ORG!pbs!pstinson@ucsd.edu Subject: Re: Galileo Update - 04/17/90 In article <3462@jato.Jpl.Nasa.Gov>, baalke@mars.jpl.nasa.gov (Ron Baalke) writes: > GALILEO MISSION STATUS > April 17, 1990 > > > The Galileo spacecraft is 87,395,218 miles from > Earth today traveling at 75,200 miles per hour relative to > the sun. (deleted) It is on a trajectory back toward Earth for a gravity assist on its long journey to Jupiter. > (more deleted) > The maneuver recently completed and the upcoming > maneuver in May make up the > first of several maneuvers planned this year to shape the flight > path for the flyby of Earth in December. > During flyby of Earth will Galileo be in position to study the Moon's south polar region? This area is one of the biggest question marks remaining in our picture of the lunar terrain. Detailed reconnaissance, if possible, will be useful in planning for future moonbases. ------------------------------ Date: 24 Apr 90 13:24:00 GMT From: primerd!ENI!ENO!DWOLFF@bloom-beacon.mit.edu Subject: Re: Pegasus launch is a success! Yet Another Pegasus Launching Idea... Actually, the first time I saw a reference to "winch-launched" Pegasi, I thought they meant like gliders: a winch sitting on the ground that accelerates a Pegasus sitting on the ground (well, on a dolly) to a high speed. Seems to me that a decent winch could get our Peg up to several hundred miles per hour. Advantages: o Really cheap (I assume big winches already exist) o Really simple -- no planes, no pilots, etc., just a winch, a dolly, and a Pegasus o All your launching equipment is sitting on the ground (easy to make repairs) o Unaffected by weather (assuming Pegasus cares less about the weather than your average plane with a crew) Disadvantages: o Pegasus still has to launch through entire atmosphere o Direction of launch is limited by where the winch is (let's put it on a dolly too!) Comments? David Wolff dwolff@eno.prime.com or DWOLFF%s41.prime.com@relay.cs.net Disclaimer: the above posting is not intended to represent Prime policy. ------------------------------ End of SPACE Digest V11 #320 *******************