Date: Thu, 4 Mar 93 07:03:34 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #272 To: Space Digest Readers Precedence: bulk Space Digest Thu, 4 Mar 93 Volume 16 : Issue 272 Today's Topics: Battery help needed! Book Computers/AI in Shuttle-SSF Bullets in Space (2 msgs) IMDISP 7.9 and VESA Latest on Geminga (2 msgs) Scientists Foresee Strengthening El Nino Event Space Scientist Why Apollo didn't continue? 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: 3 Mar 1993 18:00:28 -0600 From: Lynne K Wahl Subject: Battery help needed! Newsgroups: sci.space,sci.electronics,sci.aeronautics,sci.chem,sci.engr >>In article henry@zoo.toronto.edu (Henry Spencer) writes: >>> >>>I think I'd look into the sexier battery technologies, like nickel-hydrogen >>>or silver-zinc, first. >> >>And just how does one decide which batteries are "sexy" :-) Actually you may do better checking out the medical area. One of the people here at work has a portable piece of medical equipment that drains normal batteries flat in no time, but he can use a special battery that lasts for over two days (but costs 12x as much). -- --Lynn Wahl lwahl@matt.ksu.ksu.edu | The meek will inherit the Kansas State University Student | earth, the rest of us are Soil Conservation Service Computer Specialist | going to the stars. ----* ------------------------------ Date: 3 Mar 93 19:20:20 GMT From: "J. Porter Clark" Subject: Book Computers/AI in Shuttle-SSF Newsgroups: sci.space gwh@soda.berkeley.edu (George William Herbert) writes: >In article jpc@avdms8.msfc.nasa.gov (J. Porter Clark) writes: >>I don't think the EMU's have IR or anything really advanced in the way >>of comm equipment. They were using UHF radios dating back to the >>Apollo program last time I looked; they worked somewhere around 250 >>MHz. There is a new comm system being developed for the Shuttle and >>SSF, but it too is UHF (TDMA, though!) somewhere between 410-420 MHz. >>This would be used in the EMU's. >These are the same 4.5 kilo radios? Argh. >We tried to figure out where the mass and energy consumption was going >in those boxes (given black-box characteristics but not the insides, >we didn't have _complete_ EMU plans). Someone finally guessed "Heaters >for the Tubes". We think that they were right 8-( That must be the previous generation of equipment. I talked to some of the JSC folks who were in town for the SSF MTC CDR and they told me, in no uncertain terms, that the current EVA radios use no tubes. Of course, if they did, maybe they would be good IR sources. 8-) BTW, I goofed slightly in the earlier posting. The EVA radio frequencies (there are three) are between 250 and 300 MHz and not "around 250 MHz" as I stated earlier. I had forgotten about the wide spread among the three. -- J. Porter Clark jpc@avdms8.msfc.nasa.gov or jpc@gaia.msfc.nasa.gov NASA/MSFC Flight Data Systems Branch ------------------------------ Date: 2 Mar 1993 07:40:23 GMT From: George William Herbert Subject: Bullets in Space Newsgroups: sci.space In article <1993Feb28.171610.10261@ucsu.Colorado.EDU> fcrary@ucsu.Colorado.EDU (Frank Crary) writes: >(By the way, the rifleman wouldn't fly backwards under the recoil, as >is often thought: The linear momentum transfer is quite small and >the shooter's final velocity would be under 1 m/s (3.6 km/hr). The >angular momentum, however, is very significant: If he fired the rifle >from the shoulder, he'd wind up spinning at something like 50 rpm...) *laugh* oh dear god, that roleplaying game is coming back to haunt us already, Frank 8-) [Frank and I spent umm two weeks figuring out the physics of zero-G weapons usage as part of a realistic game we were trying to develop. I've still got the "how big a bullet does it take to shoot through a spacecraft hull and depressurize (slowly) the craft" calculations around here somewhere. We spent days arguing over deformation and momentum transfer during impact and finally decided that we'd test our numbers on some aluminum sheet at a shooting range. I never got around to that last part... sigh.] [and now back to your usual sci.space *highly technical* disucssions 8-) ] -george ------------------------------ Date: Wed, 3 Mar 1993 18:41:29 GMT From: Gary Coffman Subject: Bullets in Space Newsgroups: sci.space In article <731117525.0@aldhfn.akron.oh.us> Ryan_Potts@aldhfn.akron.oh.us (Ryan Potts) writes: >But isn't o2 needed to aid in the combustion of the gunpowder in the round? :) >Ryan Shame on you Ryan, starting this chestnut again. There are children in the audience. :-) Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: 1 Mar 93 19:22:33 GMT From: Ron Baalke Subject: IMDISP 7.9 and VESA Newsgroups: sci.space,sci.astro In article <1993Jan28.182712.12907@kakwa.ucs.ualberta.ca>, martin@space.ualberta.ca (Martin Connors) writes... >Having had IMDISP7.7a give sort of good results with VESA VGA (nice >display of images except there were horizontal lines every 100 or so >lines), I downloaded 7.9 and find that I cannot get images to display >properly at all - sometimes nothing, sometimes a vertical white bar. >Anyone got VESA experience with imdisp 7.9. BTW this is with a Local Bus >Tseng T4000-based clone? board, and I use a VESA driver (ETIVESA) in a DOS >shell under Windows. IMDISP currently does not support VESA. There were some experimental VESA drivers put in about a year ago, and it somewhat works with some of the ET4000 graphic boards. IMDISP has never been advertised to work with the VESA drivers, but I do plan to add them in. Right now, the VESA drivers are number 4 on my priority list. First, I'm fixing a bug with the DISP CEN command (so that the JEI CD-ROM can be released), and then add lat/lon for the Magellan and Viking CD-ROMs, and add image tiling for the Magellan CD-ROMs. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Every once in a while, /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | try pushing your luck. |_____|/ |_|/ |_____|/ | ------------------------------ Date: Wed, 3 Mar 1993 21:22:41 GMT From: gawne@STSCI.EDU Subject: Latest on Geminga Newsgroups: sci.space,sci.astro Given the recent discussion of Geminga, I thought there might be general interest in this: From PHYSICS NEWS UPDATE Number 116 March 3, 1993 GEMINGA'S PROPER MOTION has been measured. Geminga is a pulsar that emits almost all its energy at gamma wavelengths. Its x-ray emission is weaker by a factor of 1000 and its optical emission---if the identification of an object called G'' as Geminga's optical counterpart is correct---is 2 million times less than the gamma; it seems to emit no radio at all. Italian astronomers at the Universities of Milan and Cassino have now reanalyzed optical images recorded over the period 1984-92 and have determined that Geminga moves across the sky at a rate of 0.17 arcsec/year and that its distance from Earth is about 300 light years (G.F. Bignami et al., Nature 25 Feb. 1993.) In the following article in the same issue of Nature, Neil Gehrels and Wan Chen of NASA/Goddard suggest that the supernova that created Geminga also created the "Local Bubble," the hot, low-density region of interstellar space containing our solar system. Taking into account Geminga's velocity and dating the presumed supernova (about 340,000 years ago) with Gamma Ray Observatory data on the slowing of Geminga's spin rate, Gehrels and Chen conclude that the supernova might have been in the right place to clear away the gas in our vicinity, leaving behind the bubble. (Science News, 2 Jan. 1993.) -Bill Gawne, Space Telescope Science Institute "Forgive him, he is a barbarian, who thinks the customs of his tribe are the laws of the universe." - G. J. Caesar ------------------------------ Date: Wed, 3 Mar 1993 22:37:44 GMT From: Keith Mancus Subject: Latest on Geminga Newsgroups: sci.space,sci.astro In article <1993Mar3.162241.1@stsci.edu>, gawne@stsci.edu writes: > Given the recent discussion of Geminga, I thought there might > be general interest in this: > > From PHYSICS NEWS UPDATE Number 116 March 3, 1993 > > GEMINGA'S PROPER MOTION has been measured. Geminga is a pulsar that > emits almost all its energy at gamma wavelengths. > ...Neil Gehrels and Wan Chen of NASA/Goddard suggest that the > supernova that created Geminga also created the "Local Bubble," the > hot, low-density region of interstellar space containing our solar > system. > (Science News, 2 Jan. 1993.) Does this mean the density of hydrogen in interstellar space near the solar system is significantly lower than the average density across the Milky Way galaxy? -- Keith Mancus | N5WVR | "Money is never *mere*. It separates the feasible | from the infeasible." | ------------------------------ Date: Sat, 27 Feb 1993 16:32:50 GMT From: Chuck Fisher Subject: Scientists Foresee Strengthening El Nino Event Newsgroups: sci.space,sci.geo.meteorology Has there been any forecast to increased rainfall in California due to this new El Nino event? For at least the last decade the popular news media has linked heavy rainfall in the Western states and California in particular to El Nino events. This year has seen a much higher precipitation level than for the past seven years and somewhat reminiscent of the '82-'83 season which was "blamed on" an El Nino which was present during that period. Are there any generally accepted models which forecast precipitation changes based on El Nino events? Just another weather-watcher. Chuck -- Chuck Fisher (800) 359-7997 Work ncselxsi system administrator (415) 964-2819 Home uucp: ...!netcom!ncselxsi!fisher ------------------------------ Date: Wed, 3 Mar 1993 21:10:57 GMT From: gawne@stsci.edu Subject: Space Scientist Newsgroups: sci.space In article <1n2tu1INNqu6@elroy.jpl.nasa.gov>, tjt@Jpl.Nasa.Gov (Tim Thompson) writes: My experience is that almost all of the scientists who pursue "independent" research, or run projects, or supervise research, etc., have a Ph.D. Most of those are in the physical sciences, since that's most of what NASA does [...remainder deleted] Seems I recall hearing once that NASA employed almost as many MD's as PhD's. We on the physical sciences side are prone to forget that part of the space program. Someone aspiring to a career in space related sciences should know about the medical/biological side of NASA funded research too. -Bill Gawne, Space Telescope Science Institute "Forgive him, he is a barbarian, who thinks the customs of his tribe are the laws of the universe." - G. J. Caesar ------------------------------ Date: 3 Mar 93 23:08:25 GMT From: Dave Michelson Subject: Why Apollo didn't continue? Newsgroups: sci.space In article <2263@epochsys.UUCP> jcook@epoch.com writes: >I have also seen quotes in two places (I'll find the references >if you want) that said they were also beginning to worry about "losing one." >This may be "sour grapes" or something similar, but the opinions were not >qualified as such. Sometime ago, IEEE Spectrum ran a retrospective piece on the Apollo program in which Robert Gilruth (former Director, JSC) and a colleague commented that `there was a certain amount of relief when the moon landing program came to an end'. It was only a matter of time before they had a serious accident - they didn't expect that their luck would run forever... --- Dave Michelson University of British Columbia davem@ee.ubc.ca Antenna Laboratory ------------------------------ End of Space Digest Volume 16 : Issue 272 ------------------------------