Date: Wed, 28 Oct 92 05:03:26 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #352 To: Space Digest Readers Precedence: bulk Space Digest Wed, 28 Oct 92 Volume 15 : Issue 352 Today's Topics: A career in the Space Program - or Forget It!? Comet Collision DataBase of all space flights a/v ? HRMS for ETI MET-4 VHRR mystery lifting body craft depicted Recognizing a Dyson sphere if you saw one Slush Hydrogen question (2 msgs) Smith-Tuttle Comet a threat to earth? Two-Line Orbital Element Set: Space Shuttle very small astro science sensors?? VIDEOTAPE OF OCT 9 FIREBALL Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 27 Oct 92 19:59:42 GMT From: Jack Romachek Subject: A career in the Space Program - or Forget It!? Newsgroups: sci.space >> Should I try some new approach to job hunting in aerospace, or should >> I totally concentrate on my other interest which is molecular biology? >It all depends on you. If working in Aerospace is of such high intrinsic >value to you, then you should push for it and nothing else, but ya got to >be willing to go anywhere for it.... Sounds like a search for the Holy Grail... >JPL may not be the best place to start >off from....in fact anywhere in So Ca will be a waste.... JPL is the only place I have solid contacts. In fact, I was employed on the Voyager Project before returning to finish my degree in San Diego. I had expected return to JPL with the possibility of advancement, but my friends are laying people off, and not hiring... I am told that this is NASA-wide. >Aerospace jobs >are to be had, but in Georgia and Arizona..... Could you be more specific, what's in Georgia and Arizona? Are they immune from getting cut on the next round? >Remember, it has to be of >great importance to you....otherwise the grass will always seem greener >when you look at other industries or professions.... There has to be better advice than this, like some solid facts on available positions vs. number of applicants. My specialty is space navigation and guidance, but if after three or four years of waiting for a position to open and seeing continual layoffs and budget cuts, then it becomes fairly clear that is not the way to go. ------------------------ romachek@golem.ucsd.edu ------------------------------ Date: Wed, 28 Oct 1992 04:06:32 GMT From: "Richard A. Schumacher" Subject: Comet Collision Newsgroups: sci.space >There is a greater change of dying from a train wreck or a car accident than >getting plowed by the comet. Agreed, since all of us will be dead anyway when P S/T returns. I still maintain that any single, forseeable event which would kill all of humanity deserves to be called a tremendous danger. >Another thing to consider: How big is this comet? It doesn't have to hit >us to do some major damage. YOOGE tidal waves, earthquakes, knocking >the earth out of it's orbit, etc. Y'know...minor worldwide disaters. No. It's a dirty iceball about 10 km wide at the most, so it masses less than the island of Manhattan. If it doesn't actually hit the Earth, the only effect will be one a hell of a spectacular show in space. ------------------------------ Date: Wed, 28 Oct 1992 09:05:16 GMT From: Hartmut Frommert Subject: DataBase of all space flights a/v ? Newsgroups: sci.space Hi, Is there any comprehensive database on all spaceflights/launches/projects a/v, including name, launch date/time, payload, orbit, etc, from the beginning in 1957, for use on PC ? (Best PD or cheapware, optimal via ftp) Thanx for any pointer. -- Hartmut Frommert Dept of Physics, Univ of Constance, P.O.Box 55 60, D-W-7750 Konstanz, Germany -- Eat whale killers, not whales -- ------------------------------ Date: 28 Oct 1992 03:38:57 GMT From: "David M. Palmer" Subject: HRMS for ETI Newsgroups: sci.space,sci.bio nickh@CS.CMU.EDU (Nick Haines) tried to write: > [... stuff, including reference, about how life probably emerged here ...] > My guess for P(life evolving | suitable planet) is 1e-12. One way to estimate P(life | suitable planet), while adjusting for the weak local anthropic principal ("how strange that we should be on a planet which has life---NOT!" :-)) is to look at how long it took life to evolve, and compare that to the length of the 'window of opportunity' in whch life like ours could have started--not so early that the Earth got resterilized by continued planetery bombardment and not so late that there is no time to develop Usenet before the Sun becomes inhospitable. It turns out that life occurred just about as soon as the Earth was tolerable, like within 100 million years (this number is approximate, I don't know offhand the actual number. Nobody does.) (This leads to speculation that life may have developed one or more times earlier as well, but was wiped out each time when the next planetesimal was accreted.) This is very near the start of the window, which is roughly 5 billion years long as a rough number. This is compatible with a P(life | suitable planet) ~ 1. If P(life | suitable planet) were small, then on those planets which did, against the odds, develop life, there would be no preference for the beginning of the window rather than the end, and much preference for the big, wide middle. However, until about 600 Million years ago, life didn't seem to do much evolving, (from a fossil-viewing, anthropocentric, politically incorrect dead-white-European-male viewpoint :-)). If the Cambrian explosion (see this Month's Scientific American for a report on this) had been delayed by a factor of three (which is nothing in terms of astrophysics and the statistics of small numbers) brains might not have evolved before old Mr. Sun decided to stretch out a bit and eat the inner planets, a few billion years from now. (Sorry about the tenses in the last sentence. I don't know how to conjugate English verbs in the combined contrafactual subjunctive past-factual future tense, if that is indeed the tense I should have used.) This suggests that P(brains | life) is not close to 1, and so life does not imply that brains (or even creatures more complex than a jellyfish) will eventually arise. However, P(brains) can be pretty low without making SETI hopeless. -- David Palmer palmer@alumni.caltech.edu ------------------------------ Date: Mon, 26 Oct 1992 10:29:33 +0000 From: Andrew Haveland-Robinson Subject: MET-4 VHRR Newsgroups: sci.space In article bertilg@epix.hks.se@bertilg writes: >Hello, >We are two computer engineers working on a project in reciveing weather >sattelite pictures. Now we wonder if anyone has recieved high resolution >pictures from MET-4 somwhere in Europe. We also want some advice on which >reciever to use and software to use. Can't help much, but you could try ftp from cumulus.met.ed.ac.uk Change directory to "images". IR and visible images of Europe from Meteosat, twice daily, in 1152 x 900 GIF format (size of Sun root window). The subdirectory "gifs" has smaller 3x daily images of the Nordic areas, the UK, and Europe. Mail root@met.ed.ac.uk for further info. Andy. +-----------------------------------------------------------------------+ | Haveland-Robinson Associates | Email: andy@osea.demon.co.uk | | 54 Greenfield Road, London | ahaveland@cix.compulink.co.uk | | N15 5EP England. 081-800 1708 | Also: 0621-88756 081-802 4502 | +-----------------------------------------------------------------------+ >>>> Those that can, use applications. Those that can't, write them! <<<< ------------------------------ Date: Wed, 28 Oct 1992 00:12:41 GMT From: Dennis Newkirk Subject: mystery lifting body craft depicted Newsgroups: sci.space In November's "Monitoring Times" (a magazine for radio hobbiests) there is a 3 view drawing (page 43) from an anonymous source of a small aircraft which the magazine links to the August 5 encounter of United flight 934 747 and a small fast wingless aircarft over the California desert (recently reported in Av Week, etc..) The magazine states that the sketch is of a vehicle tested recently on a hypersonic sled test track at Holloman AFB, NM. The magazine also repeats stories of a small fast wingless craft that were in Av Week a couple months ago. For those who can't find the magazine at their news stand, I will attempt to describe the drawing: basic shape and size (judging from canopy size) is very similar to the X24-B, but with an added curved underside. Add to that large flaired chines (like an SR-71's) to the nose and inward canted tail surfaces like the F-177 prototype. Dennis Newkirk (dennisn@ecs.comm.mot.com) Motorola Inc, Land Mobile Products Sector Schaumburg, IL ------------------------------ Date: 28 Oct 92 00:49:43 GMT From: Erik Max Francis Subject: Recognizing a Dyson sphere if you saw one Newsgroups: sci.astro,sci.space train@ccwf.cc.utexas.edu writes: > I may be wrong about this, I forget the aprroximate size of a dwarf star and > wouldn't be anything near the size of a dwarf star would it? I thought dwarf > stars, at least white dwarfs, were about the size of the Earth. "Dwarf" usually means main-sequence dwarf, which is the same class of star that the Sun is. Main-sequence stars can be all sorts of sizes, ranging from very large and massive O or B stars to very dim and cool M stars. Our sun, a G2 V main-sequence star, is above average, though. ---------- Erik Max Francis Omnia quia sunt, lumina sunt. Coming soon: UNIVERSE _ | _ USmail: 1070 Oakmont Dr. #1 San Jose CA 95117 ICBM: 37 20 N 121 53 W _>|<_ UUCP: ..!apple!uuwest!max Usenet: max@west.darkside.com 464E4F5244 | ------------------------------ Date: Sun, 25 Oct 1992 23:54:44 GMT From: Jeff Greason ~ Subject: Slush Hydrogen question Newsgroups: sci.space If I can fit another technical question in between the election-year propoganda... I've been wondering about "slush" hydrogen ever since hearing about it as part of the X-30(NASP) program. I had always thought it was partially frozen hydrogen, in an attempt to get the volume for hydrogen tanks down to a reasonable level. However, I've been unable to find any information other than verbal descriptions of it (no numbers), and my initial assumption about frozen hydrogen doesn't seem to hold up, as my CRC says: Density(liquid) 70.8g/l @-253 degrees C Density(solid) 70.6g/l @-262 degrees C Now it is certainly possible that the density increases as the temperature continues to decrease, but I don't have that information. Can someone explain this to me? P.S. I still have received no information on the real drive source for solar sails. Help! Disclaimer: All opinions expressed are my own, and do not reflect the position of Intel, Portland State University, or Zippy the Pinhead. ============================================================================ Jeff Greason "You lock the door ... And throw away the key. There's someone in my head, but it's not me." -- Pink Floyd ------------------------------ Date: 28 Oct 92 04:23:34 GMT From: Josh 'K' Hopkins Subject: Slush Hydrogen question Newsgroups: sci.space greason@ptdcs2.intel.com (Jeff Greason ~) writes: >P.S. I still have received no information on the real drive source for >solar sails. Help! A solar sail is just a big sheet of reflective material. The "drive source" is the sun - the sail is pushed by radiation pressure from light. -- Josh Hopkins jbh55289@uxa.cso.uiuc.edu "We can lick gravity, but the paperwork's a bit tougher." Wernher von Braun ------------------------------ Date: Wed, 28 Oct 1992 02:28:39 GMT From: James Davis Nicoll Subject: Smith-Tuttle Comet a threat to earth? Newsgroups: sci.space In article , mcdonald@aries.scs.uiuc.edu (J. D. McDonald) writes... >In article steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes: > > >>Speed relative to Earth is 50 km/s >Lord Almighty! 1/6 the speed of light!!!!!! ??????? Hmmm. That would make a lightyear about 63 AU, Alpha Centauri about 260 AU away, and light from the sun would take about 5 days to reach Earth. Earth orbits at 0.6 'C', and I *think* the sun should be a blackhole if C=50 km/s.... I think you're a tad low on the value of C. ------------------------------ Date: 28 Oct 92 06:22:45 GMT From: TS Kelso Subject: Two-Line Orbital Element Set: Space Shuttle Newsgroups: sci.space The most current orbital elements from the NORAD two-line element sets are carried on the Celestial BBS, (513) 427-0674, and are updated daily (when possible). Documentation and tracking software are also available on this system. As a service to the satellite user community, the most current elements for the current shuttle mission are provided below. The Celestial BBS may be accessed 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using 8 data bits, 1 stop bit, no parity. Element sets (also updated daily), shuttle elements, and some documentation and software are also available via anonymous ftp from archive.afit.af.mil (129.92.1.66) in the directory pub/space. STS 52 1 22194U 92 70 A 92300.93750000 .00103280 00000-0 25599-3 0 127 2 22194 28.4623 88.9806 0006174 316.5369 265.3455 15.94356868 673 -- Dr TS Kelso Assistant Professor of Space Operations tkelso@afit.af.mil Air Force Institute of Technology ------------------------------ Date: 27 Oct 92 16:57:45 GMT From: Les Degroff Subject: very small astro science sensors?? Newsgroups: sci.astro,sci.space Day dreaming; thinking about writing a SF story I hit upon an interesting "creative" problem which I would appreciate any non proprietary ideas on. What kind of measurements could be made by sensors or systems of sensors that would fit through a 1 mm hole in 10 milliseconds. (measurements must be completed in 10 milliseconds) Is there any way one could expect to locate the probes location with sensors of that size in that short of time. (assume the location is within the local galactic cluster, and you can post process data as much as needed.) Les DeGroff (I may try to write this story if I can find or figure out some plausible solutions to the technical problem) ------------------------------ Date: Wed, 28 Oct 1992 01:07:26 GMT From: pbrown@uwovax.uwo.ca Subject: VIDEOTAPE OF OCT 9 FIREBALL Newsgroups: sci.astro,sci.space For anyone out there who might have taken actual video of the Oct 9 fireball seen over the East Coast of the US at about 8 p.m. (or know of someone who did) could you PLEASE send me an email note with that information. A group of interested meteor astronomers are tracking down all avaliable video tapes of the event to determine an orbit for the object. At present we have uncovered 17 seperate video tapings of the event from several states. The fireball produced a meteorite which hit the trunk of a high school student's car in Peekskill, New York. Though scientists were only "loaned" the meteorite for a one week period (before the owner wanted it back for the auction block) enough physical and chemical details of the object were measured to make a decisive classification. The meteorite turned out to be an L6 chondrite - a very common type. But, since there is likely enough information out there (still largely hiding ;) ) to determine an orbit the event is very unusual. If your local station ran a locally shot video of the event on the night of Oct 9 I would be very, very interested to get that information. If you know of someone at a football game that night with a camcorder the odds are pretty good they may have some valuable tape. In any case please pass along any such information on the event. Peter Brown Dept. of Physics University of Western Ontario London, Ontario N6A 3K7 Canada peter@canlon.physics.uwo.ca **************************************************************************** ------------------------------ End of Space Digest Volume 15 : Issue 352 ------------------------------