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 ; Fri, 19 Jan 90 01:38:36 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Fri, 19 Jan 90 01:38:12 -0500 (EST) Subject: SPACE Digest V10 #444 SPACE Digest Volume 10 : Issue 444 Today's Topics: Re: JPL Microbots British Interplanetary Society (was Re: JPL Microbots) Magellan Update - 01/17/90 Re: Edwards AFB Re: booster pollution JPL Microbots Re: booster pollution Cosmic Dark Matter Re: NASA Funding Galileo Update - 01/17/90 Re: Airlocks & Life support ---------------------------------------------------------------------- Date: 18 Jan 90 15:47:53 GMT From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!kcarroll@tut.cis.ohio-state.edu (Kieran A. Carroll) Subject: Re: JPL Microbots > yamauchi@cs.rochester.edu (Brian Yamauchi) writes: > > I remember reading that JPL was investigating the use of > microbots as planetary rovers (perhaps in conjuction with Rodney > Brooks' research group at MIT?). > > Does anyone have the names of the people involved or a > reference to any publications describing this work? As it happens, yes I do. See Jones, Ross M.; "Think Small - In Large Numbers"; Aerospace America; October 19, 1989; pp. 14-17 for an article on several types of microspacecraft, including ones designed at JPL. And, if you're luucky enough to have access to the Journal of the British Interplanetary Society, see the October 1989 issue. It's a special "Small Mission Systems" issue, and contains 9 articles on microrobots and microspacecraft (award for the most amusing title goes to Rodney Brooks and Anita Flynn, for "Fast, Cheap and Out of Control: A Robot Invasion of the Solar System" in this issue, about the microrobots developed at MIT's AI Lab). -- Kieran A. Carroll @ U of Toronto Aerospace Institute uunet!attcan!utzoo!kcarroll kcarroll@zoo.toronto.edu ------------------------------ Date: 18 Jan 90 21:12:02 GMT From: zaphod.mps.ohio-state.edu!sunybcs!uhura.cc.rochester.edu!rochester!yamauchi@think.com (Brian Yamauchi) Subject: British Interplanetary Society (was Re: JPL Microbots) In article <1990Jan18.154753.14508@utzoo.uucp> kcarroll@utzoo.uucp (Kieran A. Carroll) writes: > >And, if you're luucky enough to have access >to the Journal of the British Interplanetary Society, see the October >1989 issue. It's a special "Small Mission Systems" issue, and contains >9 articles on microrobots and microspacecraft (award for the most >amusing title goes to Rodney Brooks and Anita Flynn, for "Fast, Cheap >and Out of Control: A Robot Invasion of the Solar System" in this >issue, about the microrobots developed at MIT's AI Lab). Is there an address for the British Interplanetary Society from which I could order back issues (specifically, *this* back issue)? Thanks, _______________________________________________________________________________ Brian Yamauchi University of Rochester yamauchi@cs.rochester.edu Computer Science Department _______________________________________________________________________________ ------------------------------ Date: 18 Jan 90 18:51:59 GMT From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@tut.cis.ohio-state.edu (Ron Baalke) Subject: Magellan Update - 01/17/90 MAGELLAN STATUS REPORT Jan. 17, 1990 Today, the Magellan spacecraft is 113,471,037 miles from Earth, traveling at a speed of 63,409 miles per hour relative to the sun. One way light time is 10 minutes and 12 seconds. The spacecraft has been successfully switched back to its primary command data system computer, and to the high-gain antenna. The data rate is again at 1,200 bits per second. Earlier this month the spacecraft detected an error in its memory and went into a safing mode. It switched to its backup CDS computer and the telemetry link was switched from the high gain to the medium gain antenna and the rate was reduced from 1,200 bits per second to 40 bps. Also, the command link was switched from the high gain to the low gain and the rate was reduced from 62.5 bps to 7.8 bps. On January 12, the spacecraft went into fault protection mode due to a wrong command to the spacecraft from the spacecraft team. After performing a sweep at 300Hz with a tuning rate of 5Hz/sec, two way communications was once again established. A momentum wheel desaturation was done once daily via non- standard commands to the spacecraft. Magellan operations team members said Magellan is back on schedule for the start of Cruise-17 command sequence Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 18 Jan 90 16:35:58 GMT From: skipper!belle@ames.arc.nasa.gov (Steve Belle) Subject: Re: Edwards AFB In article <8643@cbnewsm.ATT.COM>, rma@mhuxo.ATT.COM (atkins, robert m) writes: > I will be out in the area of Edwards AFB later this month. Are there any > visitor facilities or public exhibits there that would make a detour > worthwhile? Thanks in advance for any replies. > > Bob Atkins > att!mhuxo!rma NASA's Dryden Flight Research Facility has a public tour twice a day, Monday through Friday, except for holidays and the week preceding a shuttle landing. The tour includes a film that describes the various flight research projects that have been done here (about 30 min) and a tour of the main hangar that houses the current research vehicles (about 30-40 min). After the tour, you are free to check out the gift shop which also contains several exhibits about NASA's flight research history. Steve belle@skipper.dfrf.nasa.gov ------------------------------ Date: 18 Jan 90 16:26:42 GMT From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: booster pollution In article <0Zgv2xK00XcS4==Vhj@andrew.cmu.edu> dd2f+@andrew.cmu.edu (Daniel Alexander Davis) writes: >Also, I heard someone mention a local problem >of heat pollution adversely affecting the ecology >of Cape Canaveral... Sounds very implausible. A shuttle launch is maybe 20-30 gigawatts of power for half a minute or so (it climbs quickly, remember). Sunlight is roughly a gigawatt per square kilometer, continuously. Any effects from launches would be transient and localized. -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 17 Jan 90 21:58:20 GMT From: rochester!yamauchi@louie.udel.edu (Brian Yamauchi) Subject: JPL Microbots I remember reading that JPL was investigating the use of microbots as planetary rovers (perhaps in conjuction with Rodney Brooks' research group at MIT?). Does anyone have the names of the people involved or a reference to any publications describing this work? Thanks, _______________________________________________________________________________ Brian Yamauchi University of Rochester yamauchi@cs.rochester.edu Computer Science Department _______________________________________________________________________________ ------------------------------ Date: 18 Jan 90 00:23:06 GMT From: rochester!dietz@pt.cs.cmu.edu (Paul Dietz) Subject: Re: booster pollution In article <13353@cit-vax.Caltech.Edu> kimf@tybalt.caltech.edu.UUCP (Kim Flowers) writes: >Hey, what about all those HOH molecules them hydrogen-oxygen boosters >are spreading all over the place! Could be a real problem... :) Actually, they could be, if the launch rate is high enough (read: much larger than now). The upper stratosphere is extremely dry. If we inject water there, it could form high altitude ice clouds, especially in polar regions. Such clouds cause net warming by reflecting infrared radiation. Also, ice clouds in the Antarctic stratosphere are thought to play a part in the formation of the ozone hole. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 17 Jan 90 17:29:31 GMT From: frooz!cfa.HARVARD.EDU@husc6.harvard.edu (Steve Willner, OIR) Subject: Cosmic Dark Matter From article <9364@hoptoad.uucp>, by tim@hoptoad.uucp (Tim Maroney): > So many scientists seem to take the dark matter for granted, I'n not sure this is true, but press reports may make it seem so. > but I've yet to see any clear reason for > postulating it other than a sort of religious dogma that the universe > will eventually recollapse. Is there really any stronger basis for > believing that we only see ten percent of the universe, or are people > letting their aesthetics guide their modeling? There are actually two separate questions that are often confused. The first is best called the "Hidden Mass Problem." Gravitational evidence, including rotation curves, the stability of spiral galaxy disks, and the dynamics of clusters of galaxies imply that galaxies have about 3-10 times more mass than estimated for the visible stellar population. The "hidden mass" is distributed in roughly the same way as the visible mass; i.e., it accompanies the observed galaxies. The debate now is over the form of this matter, not its existence. Possibilities include "brown dwarfs" or almost anything else (black holes, "planets") in the mass range between 0.05 and 0.005 solar mass. There are other possibilities as well. The second problem is usually called the "Missing Mass Problem." Even accounting for the hidden mass, observable galaxies add up to only 0.3 or less of the "critical mass," i.e., the maximum mass allowed where the Universe expands forever (not recollapses). As far as I can tell, there is indeed no observational evidence for existence of the "missing mass;" indeed, there is considerable evidence that the "missing" mass, if it exists, cannot be in the form of baryons. The "missing mass" must also _not_ accompany the visible galaxies but rather must be more uniformly distributed through the Universe. Theorists often (always?) "let their aesthetics guide their modeling." What's wrong with that? The relevant questions are whether models are ruled out by existing data and whether simpler models would explain the data just as well. The answer to the first is "maybe" and to the second "no". Models with mass lower than critical invoke either coincidence or some other component just as arbitrary as non-baryonic dark matter. Both the "hidden mass" and the "missing mass" questions are at the forefront of research these days, which means that nobody knows the right answers. ------------------------------------------------------------------------- Steve Willner Phone 617-495-7123 Bitnet: willner@cfa 60 Garden St. FTS: 830-7123 UUCP: willner@cfa Cambridge, MA 02138 USA Internet: willner@cfa.harvard.edu ------------------------------ Date: 19 Jan 90 03:38:27 GMT From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: NASA Funding In article <90018.112552AEA1@PSUVM.BITNET> AEA1@PSUVM.BITNET (Amy Antonucci) writes: >As I understand it, NASA is under the gov't so that anything that NASA may >get goes to Congress and then Congress decides how much to give back. Yup. Some years ago, when the Viking Fund had collected a substantial amount of money as a show of public support for keeping Viking Lander 1 operational (there was talk of shutting it down), complications arose when the time came to hand it over. The government apparently can't accept donations earmarked for specific projects or groups. I believe it was eventually worked out with the Fund contracting with JPL for Viking data-analysis work, which was desirable in itself and also eased pressure on the Viking budget a little. (The political point had been made anyway.) -- 1972: Saturn V #15 flight-ready| Henry Spencer at U of Toronto Zoology 1990: birds nesting in engines | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 18 Jan 90 18:51:23 GMT From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@tut.cis.ohio-state.edu (Ron Baalke) Subject: Galileo Update - 01/17/90 GALILEO MISSION STATUS January 17, 1990 Today the Galileo spacecraft is just under 18 million miles from Earth, and 8.7 million miles from Venus. Round-trip light time to the spacecraft is about 3-1/4 minutes. During the next week or so, there will be an approximate line-up between the Sun, Venus, Galileo, the Earth and Jupiter. (Jupiter was at opposition two weeks ago, and the spacecraft is several degrees above the ecliptic plane.) Galileo has rolled up 141 million miles around its orbit, at a velocity which has increased to 75,600 mph, and with 44 million to go before Venus encounter February 9 at 10 p.m. PST. The health of the spacecraft is very good; it is in a "safed" cruise mode following an incident Monday in which the attitude control computer invoked system fault protection because of an incompatibility found while performing a star calibration with the gyros off. The flight team analyzed the incident quickly and are now working to gradually restore various functions which were halted automatically during the "safing" response. The spacecraft is spinning in all spin mode at 2.89 rpm, and sending telemetry at 1200 bits per second. On January 9, Galileo had its first demonstration of "Delta DOR," a Very Long Baseline Interferometry technique using two DSN stations simultaneously to produce very precise angle tracking data. This will be added to doppler and ranging to refine spacecraft navigation for the Earth and Jupiter encounters, to improve targeting while saving propellant. The DSN's large antenna in Spain, DSS-63, has been down for several weeks to replace a bearing. Repairs are progressing and the antenna is expected to be operating in time for Venus encounter. Last week the Project determined that no further trajectory correction is needed for the Venus flyby; there will be no TCM-3. Venus encounter and science will be part of the operating sequence called EV-6, which will be effective February 5-18. Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 17 Jan 90 17:01:27 GMT From: mcsun!ukc!icdoc!syma!andy@uunet.uu.net (Andy Clews) Subject: Re: Airlocks & Life support From article <27460003@hpcvia.CV.HP.COM>, by 10e@hpcvia.CV.HP.COM (Steven_Tenney): > oops! hit the wrong button, sorry! A likely WW3 scenario, I fear! :-) 8-{ -- Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND JANET: andy@syma.sussex.ac.uk BITNET: andy%syma.sussex.ac.uk@uk.ac Voice: +44 273 606755 ext.2129 ------------------------------ End of SPACE Digest V10 #444 *******************