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 ; Sat, 12 Jan 1991 14:30:33 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 12 Jan 1991 14:29:22 -0500 (EST) Subject: SPACE Digest V13 #035 SPACE Digest Volume 13 : Issue 35 Today's Topics: Re: Humankind's Second Off-world Colony Re: shuttle was answer SPECIAL SOLAR TERRESTRIAL BULLETIN AND STRATWARM ALERT UPDATE Re: LOX/LH2 in Shuttle Payload Bay Re: Umbra (eclipse shadow) satellite photo Re: space news from Dec 10 AW&ST (TIRE DAMAGE) Re: Humankind's Second Off-world Colony Salyut orbital elements HSTMAP for IBM PC Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 9 Jan 91 22:40:22 GMT From: swrinde!zaphod.mps.ohio-state.edu!julius.cs.uiuc.edu!news.cs.indiana.edu!maytag!watmath!watdragon!watyew!jdnicoll@ucsd.edu (Brian or James) Subject: Re: Humankind's Second Off-world Colony Local power supply on Jupiter's moons? I've seen models of Europa that give it liquid water under a shell of ice. Perhaps a heat engine pumping heat from the water to the surface of Europa could be set up? I have this bad feeling the ice is inconveniently thick, though. Gee, Jupiter has that big magnetic field. How about using *that* to generate power. I have this long piece of superconducting cable to use as the orbiting armature... It's been too long since I took electricity in High School, and I'm rather foggy on the details, so there are probably showstoppers for that idea, too (and possibly gooched terminology). James Nicoll ------------------------------ Date: 10 Jan 91 00:08:48 GMT From: zephyr.ens.tek.com!tektronix!sequent!crg5!szabo@uunet.uu.net (Nick Szabo) Subject: Re: shuttle was answer In article <91009.085316GIPP@GECRDVM1.BITNET> GIPP@gecrdvm1.crd.ge.com writes: >Henry Spencer quips: > >-if the space shuttle was the answer, what was the question- > >How about: > >what is a bargain compared to many of the other Gov't "spending" >programs including, but not limited to: [examples to show NASA is not the only govnt bureaucracy wasting money] Ah, the good old "they're wasting money so we can waste money too!" argument. In private industry, a sure way to go bankrupt. But the perfect argument for a government bureaucracy seeking to feed itself. I say it three times I say it three times I say it three times: LEARN TO BE EFFICIENT. Pioneers use what they have. Whiners stay home. 'nuff said. -- Nick Szabo szabo@sequent.com Embrace Change... Keep the Values... Hold Dear the Laughter... ------------------------------ Date: Wed, 9 Jan 91 01:38:36 MST From: std_oler%HG.ULeth.CA@vma.cc.cmu.edu (Cary Oler) Subject: SPECIAL SOLAR TERRESTRIAL BULLETIN AND STRATWARM ALERT UPDATE X-St-Vmsmail-To: ST%"space+@andrew.cmu.edu" /\/\/\/\/\/\/\/\/\/\/\/\/\ SPECIAL SOLAR TERRESTRIAL BULLETIN Information Update 08 January, 1991 /\/\/\/\/\/\/\/\/\/\/\/\/\ SOLAR CONDITIONS AS OF 08 JANUARY, 1991. As was anticipated, Region 6442 (S11W59) began producing M-class flares on 08 January. It has produced three M-class flares over the past 24 hours. The first flare occurred at 04:34 UT and lasted 61 minutes. It achieved a class M1.8/1N intensity and was associated with a 640 s.f.u. (solar flux unit) radio burst at 10 cm wavelengths. The second flare occurred at 06:56 UT and lasted 20 minutes. It was rated as a class M1.1/SF flare and was not associated with any significant radio bursts. The third flare occurred at 11:27 UT and lasted 32 minutes. It was rated as a class M1.2/1N flare and was associated with a 1,100 s.f.u. radio burst at 245 MHz. The locations of these flares were at S11W48, S12W50 and S13W51 respectively. Region 6442 has begun to slow in growth and is expected to enter a decline phase after it passes beyond the west limb on 10/11 January. However, it is expected to continue to produce M-class flares throughout the remainder of it's transit over the west limb. Of perhaps equal importance were the events which have transpired over the eastern solar limb. Region 6444 (N14E65) has rotated into better view now and has revealed numerous additional trailing spots. It is not yet clear whether the trailing spots are associated with Region 6444 or with old Region 6412 (which produced two powerful X-class flares just prior to it's passage beyond the west limb two weeks ago). This determination will be made clear over the next 24 hours as the eastern regions rotate into better view. An eruptive prominence occurred on 08 January from behind the east limb. This event was associated with a long-duration class C7.5 x-ray burst, which peaked in intensity at 18:48 UT. The event lasted 72 minutes and managed to push the background X-ray flux for 08 January to a class C2.3 level (well above the C1.5 background levels measured on 07 January). In addition, this eruptive prominence was associated with a strong Type II radio sweep. It will be interesting to observe the emergence of these eastern active centers over the next several days. The threat for M-class flaring is expected to remain high for at least the next 48 hours, and likely throughout the next week. The current sunspot number is 145, but is expected to climb quite dramatically over the next 48 hours, before levelling off. The disappearance of Region 6442 beyond the west limb will produce a drop in the sunspot numbers, but Regions 6444 and the active area's just beyond the eastern limb are expected to keep sunspot numbers elevated. STRATOSPHERIC WARMING ALERT UPDATE - 08 JANUARY, 1991. The stratospheric warming alert is being continued. This alert will likely remain in effect for at least the next 7 to 10 days. The stratospheric warming has become very intense with a center over Greenland. The affected area's are continuing to expand and spread northeastwards. For those who are unfamiliar with stratospheric warming alerts, here is a brief explanation of these events. A stratospheric warming alert is issued whenever abnormally high temperatures are observed in the earth's stratosphere, which is the atmospheric transition zone between the trophosphere (the lower atmosphere we live in) and the ionosphere. Large area's of intense stratospheric warming can cause atmospheric expansion sufficient to increase drag on satellites. There is also some evidence that intense stratospheric warming events can cause changes in atmospheric circulation and weather patterns. This area is still being researched however, and is far from conclusive. Intense solar activity can cause atmospheric expansion. However, stratospheric warming events are more often associated with natural processes occurring in the earth's atmosphere. Stratospheric warming tends to occur most often during the winter months and can appear quite suddenly and intensify quite rapidly. Abnormally high temperatures in the stratosphere cause changes in stratospheric circulation patterns and other characteristic changes. They pose no threat to man, but do warrant attention. Stratospheric warmings are relatively rare. The last stratospheric warming alert was issued on 08 February, 1990 and lasted for over two weeks. This event is expected to be of a similar duration. We are in day 6 of the "Stratwarm Alerts" as of 08 January, 1991. ** End of Bulletin ** ------------------------------ Date: 9 Jan 91 16:54:12 GMT From: swrinde!zaphod.mps.ohio-state.edu!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: LOX/LH2 in Shuttle Payload Bay In article <1991Jan9.104406.14025@helios.physics.utoronto.ca> neufeld@physics.utoronto.ca (Christopher Neufeld) writes: >>Why not mount the Centaur upside down? ... > ... pictures of objects leaving the cargo bay >always show the rocket nozzle of the Centaur or IUS pointing at the >floor of the payload bay, which would make the rocket horizontal in the >launch stack configuration. Is there a gimbal which swings the whole >thing to vertical... For large payloads, the sort that go up on an IUS (or would have gone up on a Centaur), the nozzles point at the rear of the bay during launch. The IUS is held in a mounting ring which pivots to point the assembly out of the payload bay for separation. Centaur was similar. Mounting such an assembly upside down wouldn't entirely solve the problem, and would add some new ones. The payloads aren't built to carry external loads. What you really want is a more complex cradle system that would support payload and upper stage independently. -- If the Space Shuttle was the answer, | Henry Spencer at U of Toronto Zoology what was the question? | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 9 Jan 91 22:36:22 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Re: Umbra (eclipse shadow) satellite photo >From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) >Subject: Re: Could weather sat snap umbra 11-7-91? >In article <1991Jan3.162116.21912@informix.com> cortesi@informix.com (David Cortesi) writes: >>There are these fine weather satellites looking down on the west >>coast and pacific. Would it be possible for one of them to take >>pictures of the umbra, a 300 kilometer oval of shadow, as it >>sweeps over Baja or Mexico on that day? >I suspect that the answer is no. The trouble is that the Clarke-orbit >metsats typically spend about half an hour doing a raster scan of the >Earth for each image. They're not built for stop-motion photography, >even motion as slow as this. >"The average pointer, statistically, |Henry Spencer at U of Toronto Zoology >points somewhere in X." -Hugh Redelmeier| henry@zoo.toronto.edu utzoo!henry I recently saw a published satellite photograph of an umbra, with an explanation that ordinary weather satellites couldn't do it. Unfortunately, I can't remember the name of the satellite or where I saw the picture. :-( John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 8 Jan 91 14:56:39 GMT From: mcsun!ukc!tcdcs!swift.cs.tcd.ie!ccvax.ucd.ie!mhoey@uunet.uu.net Subject: Re: space news from Dec 10 AW&ST (TIRE DAMAGE) In article <1991Jan4.031224.18787@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes: > Langley engineers pleased: Atlantis's tires showed neither a spin-up gouge > nor excessive wear after the KSC landing Nov 20. The changes to the runway > surface, meant specifically to reduce tire damage, appear to have been > successful. I thought about this for a while (tire damage on landing) the last time it was mentioned, but then forgot about it - the thing that sprang to mind at the time was: why not spin-up the tires (whoops - american spelling) BEFORE landing - maybe by using ducts attached to the wheels to harness the 230mph.ish winds (230mph I think ?) Neil Conway Physics Dept. Univ. Coll. Dublin Ireland MHOEY@CCVAX.UCD.IE ------------------------------ Date: 9 Jan 91 19:53:24 GMT From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Humankind's Second Off-world Colony In article <1991Jan9.175959.7207@cadence.com> jonmon@cadence.com (Jon Monsarrat x6227) writes: >Where should Man's first colony after a moon colony be? > OUR GUESS: Ganymede because of its water supply and proximity to Jupiter > which is a good source of gases possibly used in fusion... Ganymede has the unfortunate problem of being in the outer fringes of Jupiter's Van Allen belts, as I recall. Callisto would be a better bet. >What would the motivations for having a colony be? Historically, colonies are motivated either by money or by the desire to escape oppression. The obvious economic motive for a colony on a Jovian moon is exploitation of Jupiter's resources. In particular, given cheap transport, the smaller Jovian moons might be the most convenient sources of volatile materials -- notably water -- for space activities elsewhere in the solar system. (Carbonaceous-chondrite asteroids are an alternative, but if transport is cheap enough, the problems of extracting volatiles from them might exceed their advantages of being closer in.) This requires sufficiently major space activity for there to be a lot of customers. Smaller amounts would be brought back by self-contained expeditions; only when these started becoming common would it be worth starting a base; only when supplying the base and rotating personnel started to be a nuisance would it be worth starting a colony. At an earlier stage of space activity, a Jovian moon might be a good place to start an escape-from-oppression colony. Such folks generally want isolation, the more the better, or else they'd just find somebody here on Earth willing to take them in. They wouldn't move in next to a thriving mining operation. However, they might find such an operation growing up next to them after a while. Interesting plot possibilities there. Most other possible motives for a colony, e.g. dangerous research, are better satisfied by inner-system asteroids. One major nuisance of a colony on a planetary body is that solar energy is much less available, because it's night half the time. The Jovian moons suffer in this regard because they are (as I recall) tidally locked to Jupiter, so their day/night cycle matches their orbital cycle, and is inconveniently long. >What would be the basic physics of the colony? A major aspect of this is, where does the power come from? Choices boil down to solar or nuclear, unless you can find geothermal activity. (There is lots of that on Io, but it's not good real estate. Not likely to be much on the outer moons.) >How dependent would such a colony be on Earth? This is slightly dependent on the colonists' motives; an isolationist colony will try to be independent in ways that a commercial colony would not bother with. Trace elements will probably have to come from Earth, ditto complex biochemicals and advanced semiconductors. An isolationist colony might try to get along without the last two, but would probably need very occasional trade for trace elements -- recycling systems always lose some, and even on Earth you can work long and hard to find ores of the rarer ones. A commercial colony, especially one based on cheap transport, would probably not try to be independent except in basic life support and bulk materials. >How might a Ganymede-Earth communication system work? >How often and when are there Earth-sun-Jupiter eclipses? How long are they? Earth is behind the Sun for a week or two about once a year. A Jovian moon is behind Jupiter for a small slice of each orbit. It might not be worth doing anything about either one. An isolationist colony, in any case, might want only occasional communication with Earth. A commercial colony would possibly want a comsat to avoid having Jupiter get in the way of local communications, and given that would probably use it to avoid Jupiter eclipses of Earth communication as well. >What are the long term effects of living in Ganymede's 1/7th gravity? Totally unknown. One very interesting possibility is shorter (!) lifespan; if I recall correctly, mice live longer in centrifuges than at one gee. (Yes, this is very counterintuitive, but lifespan issues abound with such surprises: slight under-nutrition also lengthens lifespan.) >If low gravity was inhospitable to man, what would be the solution? Build a space colony in orbit around Ganymede or Jupiter, or tied up to one of the really small moons (for easier access to resources). >Ganymede has a low pressure atmosphere, but what's it composition? > OUR GUESS: 5 millibars water vapor?? It will be vacuum for almost all practical purposes. -- If the Space Shuttle was the answer, | Henry Spencer at U of Toronto Zoology what was the question? | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: Wed, 9 Jan 91 12:16:32 PST From: trop@hls.com (Troy T. Pummill) Subject: Salyut orbital elements Does anyone plan to increase the frequency of orbital element update releases as Salyut gets closer "touch down" :-) trop (Troy) ------------------------------------------------------------------------------- | Troy T. Pummill | trop@hls.com | | Sr. Technical Instructor | ...uunet!lanslide.hls.com!trop | | Hughes LAN Systems | | | (415) 966-7915 | 1225 Charleston Rd., Silicon Gulch | | Mountain View, CA 94043 | The preceding drivel is entirely my own! | ------------------------------------ ------------------------------------------ ------------------------------ Date: 10 Jan 91 02:56:59 GMT From: att!emory!athena.cs.uga.edu!boone@ucbvax.Berkeley.EDU (Roggie Boone) Subject: HSTMAP for IBM PC I few days ago I read about a program called HSTMAP, apparently a program that allows one to follow the Hubble Space Telescope via a graphical representation of its orbit on a computer screen. This program was for the Macintosh computer. Is there am IBM PC version of this program available? Please email replies to boone@athena.cs.uga.edu Thank you. Roggie Boone University of Georgia ------------------------------ End of SPACE Digest V13 #035 *******************