Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Wed, 16 Jan 91 21:11:59 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 16 Jan 91 21:11:55 -0500 (EST) Subject: SPACE Digest V13 #054 SPACE Digest Volume 13 : Issue 54 Today's Topics: Re: Fwd: NASA Plans To Redesign Space Station Nuclear deep space power sources artificial aurora sighting Re: Humanity's Launch Window Galileo Update - 01/15/91 Nuclear Rockets -- Not Dead Yet Re: Metrics (was Re: Rotating Joints for Habitat) Re: Fwd: NASA Plans To Redesign Space Station Re: Cameras in 0G, was: Re: MIR Vacation Re: solar flares Re: Cameras in 0G, was: Re: MIR Vacation Magellan Update - 01/16/91 CRRES observations from Wash. D.C. 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: 15 Jan 91 17:27:54 GMT From: borg!homer!leech@mcnc.org (Jonathan Leech) Subject: Re: Fwd: NASA Plans To Redesign Space Station In article <9101151502.AA07365@iti.org>, aws@ITI.ORG ("Allen W. Sherzer") writes: |>One of the designs proposed when Congress mandated the design be evaluated |>eliminated most of the truss. A small part would be left to hang experiments |>on and the rest removed. This approach also used smaller modules for building |>the station. Each module would be self contained and could go up on a single |>Shuttle flight. A module would be flown up, docked, and ready to go. |> |>IMHO this is the best option and will result in a useable station. The |>political pressures against it however are strong. If adopted, this would help vindicate Oliver Harwood's modular tetrahedral station approach. Having the temerity to propose it got him kicked out of Rockwell in the mid-80s. -- Jon Leech (leech@cs.unc.edu) __@/ "Opossums ran amok in Chapel Hill this weekend..." _The Daily Tar Heel_, 11/1/88 ------------------------------ Date: 15 Jan 91 17:36:04 GMT From: fluke!strong@beaver.cs.washington.edu (Norm Strong) Subject: Nuclear deep space power sources Could anyone on this newsgroups tell me what nuclear fuel is used to power space probes, such as the Voyager? I know they last some time, but I can't figure out what substance is used for this purpose. Thanks a bunch. -- Norm Strong (strong@tc.fluke.com) 2528 31st S. Seattle WA 98144 ------------------------------ Date: 15 Jan 91 04:53:08 GMT From: sdd.hp.com!uakari.primate.wisc.edu!caen!malgudi!sunc.osc.edu!bob@ucsd.edu (Bob Marshall) Subject: artificial aurora sighting We observed the barium release on 15 January at 04:12UT (11:12 EST) in Columbus, Ohio under rather cloudy conditions. I saw the release...greenish, fuzzy, moon-size if the moon were up high. I observed without binoculars and saw it for about a minute. It faded quickly and was lost in the clouds, but it was possible to see it with 7x50 binoculars for several more minutes. Our viewing site is rather light polluted. Georgia Ehlers and Bob Marshall ------------------------------ Date: 15 Jan 91 06:44:07 GMT From: agate!shelby!neon!Neon!jmc@ucbvax.Berkeley.EDU (John McCarthy) Subject: Re: Humanity's Launch Window I don't agree with the idea that humanity has only 80 years before it will become too poor to go into space. I fit my definition of an extreme optimist - someone who believes that humanity will survive even if it doesn't take his advice. ------------------------------ Date: 15 Jan 91 19:32:20 GMT From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@bloom-beacon.mit.edu (Ron Baalke) Subject: Galileo Update - 01/15/91 GALILEO STATUS REPORT January 15, 1991 Yesterday's SITURN, cruise science memory readout and downlink rate change to 40 bps were all successful with the Galileo spacecraft. Today, there are no spacecraft activities planned. Tomorrow, the spacecraft will be commanded from dual-spin to all-spin operations due to the lack of valid star sets and remain in the all-spin mode until February 25. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 14 Jan 91 23:38:50 GMT From: rochester!sol!yamauchi@louie.udel.edu (Brian Yamauchi) Subject: Nuclear Rockets -- Not Dead Yet It seems I spoke too soon in my article (Who Killed Nuclear Rockets?) of a couple months ago. According to the January 7 issue of Aviation Week, NASA is establishing an Office of Nuclear Propulsion which will work on both nuclear thermal and nuclear electric propulsion for the Space Exploration Initiative. One of these technologies will be chosen by the year 2000 for further development, and a "fully functional test engine" will be built by 2005. I'm not exactly sure what a "fully functional test engine" means -- if this means a research prototype, it seems like it shouldn't take 15 years (given the previous research on NERVA), but if it means an engine that could be modified for use in an actual interplanetary spacecraft, then 2005 seems like a very reasonable date. -- _______________________________________________________________________________ Brian Yamauchi University of Rochester yamauchi@cs.rochester.edu Computer Science Department _______________________________________________________________________________ ------------------------------ Date: 15 Jan 91 12:52:17 GMT From: usc!wuarchive!zaphod!rpi!uupsi!sunic!lth.se!newsuser@ucsd.edu (Magnus Olsson) Subject: Re: Metrics (was Re: Rotating Joints for Habitat) In article <1991Jan14.195209.18076@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1991Jan14.101519.25331@lth.se> magnus@thep.lu.se (Magnus Olsson) writes: >>... even in scientific works, it is allowed to use >>prefixes with SI units. > >There is one minor exception to this. Some branches of engineering, having >been burned too many times by unit conversions, pick a single unit of (say) >length and use that for *everything*, no prefixes allowed. Metric machine >shops, for example, often do everything in millimeters, even if they're >working on something big like an airliner wing. Yes, and it's a very sensible practice, too - even though conversion between metric units is simple, eliminating the need for unit conversions eliminates one potential source of confusion. This, however, hasn't got anything to do with which unit system you're using. Magnus Olsson | \e+ /_ Dept. of Theoretical Physics | \ Z / q University of Lund, Sweden | >----< Internet: magnus@thep.lu.se | / \===== g Bitnet: THEPMO@SELDC52 | /e- \q ------------------------------ Date: Tue, 15 Jan 91 10:02:55 -0500 From: "Allen W. Sherzer" Subject: Re: Fwd: NASA Plans To Redesign Space Station Newsgroups: sci.space Cc: In article : >Given that the US has already launched a space station and the Soviets >have launched several (including a modular/expandable station), my >question is: what are the hard technical problems that are making >the Freedom design process so long (and expensive)? The technical problmes (of which there are many) pale in comparison to the political and managerial problems. When the project began, the main goal in assigning work was to insure that each center had a chunk of it and each chunk was the right size. Technical ability to carry out the assignment was secondary. In addition, NASA ignored integration issues for several years. To all outward appearances the thing was an aerospace/ NASA welfare program and nobody cared if anything was produced. >2) The Truss: In particular, building it in orbit. Someone mentioned >that the truss was cut in the latest redesign -- did this refer to >just the dual keel design (which was cut earlier) or the *entire* >truss? One of the designs proposed when Congress mandated the design be evaluated eliminated most of the truss. A small part would be left to hang experiments on and the rest removed. This approach also used smaller modules for building the station. Each module would be self contained and could go up on a single Shuttle flight. A module would be flown up, docked, and ready to go. IMHO this is the best option and will result in a useable station. The political pressures against it however are strong. The interesting question is just what this press release means. My congressional sources all say that as of last week the NASA attitude was: 'Problem? What problem? We just need to make it smaller'. However, if this release is correct there is hope that the basic problems will be looked at. Most of the pressure for change will come from the Augustine Commission. Augustine worked hand in hand with both the Space Council and the Office of Management and Budget while preparing their recomendations. Their findings and recomendations have already been blessed by both agencies and many will be implimented in next years budget. Allen -- +----------------------------------------------------------------------------+ |Allen W. Sherzer | America does best when it accepts a challenging mission. | | aws@iti.org | We invent well under pressure. Conversely, we stagnate | | | when caution prevails. -- Buzz Aldrin | ------------------------------ Date: 15 Jan 91 15:28:13 GMT From: usc!cs.utexas.edu!ut-emx!clyde@ucsd.edu (Head UNIX Hacquer) Subject: Re: Cameras in 0G, was: Re: MIR Vacation The real problem with cameras in space is not as much 0G as vacuum, which has a nasty habit of evaporating lubricants. There is also the problem of 'cold welding', which is metal getting so cold that it freezes to the adjoining metal. These days vacuum survival might not be so important. MIR and the Shuttle have airlocks, so not everything has to be exposed to vacuum whenever someone takes a stroll outside :-) The basic Hasselblad is a Single Lens Reflex camera - with a mirror that reflects light from the lens into the viewfinder, moves out of the way during the exposure and moves back into the light path after. Many SLRs rely upon gravity to **help** move the mirror back. Also the camera had to operable by an astronaut wearing space suit gloves - which are bulky to say the least. You're not going to be able to focus and shoot an Olympus OM-2 or Leica wearing those mitts. You need BIG, easily grapsed controls to turn and BIG buttons to push. The Hasselblad used by NASA did NOT have the mirror - that was one less mechanism to break. A rangefinder was mounted on the top of the camera body for aiming. More expensive, yes, but going into space ain't a trip to the beach. If you lose your vacation pictures because your camera breaks, that's too bad. If you lose pictures from your lunar landing because the camera broke, you just wasted mucho $$. -- Clyde Hoover (Shouter-To-Dead-Parrots) | UNIX/VMS Services | "Any sufficently advanced technology Compuatation Center, UT Austin | is indisguishable from a rigged demo." clyde@emx.utexas.edu | ------------------------------ Date: 15 Jan 91 22:18:27 GMT From: uhccux!milo!leka@ames.arc.nasa.gov (K.D.Leka) Subject: Re: solar flares In article <9101131000.AA21750@mozart.unx.sas.com> SNOMCB@MVS.SAS.COM ("Mike Bishop") writes: > ..... >I am interested to find out if there are any >predictions as to when any notable solar flares >may be visible to amateurs? Unfortunately, we've not got a way to absolutely predict when solar flares are going to occur - they have no regular pattern, like an orbit of a comet, by which to calculate when one is going to occur. Solar Physicists have been able to study when and under what conditions on the Sun flares are most likely to occur, and on such bases can make predictions on the likelyhood of a flare occurring (and how major it will be) in a particular active region, or spot group. For amateur viewing, only the brightest flares (read: relatively rare..) can be seen in the white-light of the photosphere, that is, the continuum radiation one sees in a projection of the sun through a telescope or such. Flares are more easily seen with an H-alpha filter. So, to try and catch a flare, get a GOOD H-alpha filter, watch the Solar- Terrestrial Alerts for reports of high flaring activity and where on the solar disk it is occurring, then sit, watch, and wait. Sometimes there will be 25 flares in a 24-hr period, sometimes none. ^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^*^ Osborn's Law: "Variables won't; constants aren't. constraints don't." K. D. Leka leka@mamane.ifa.hawaii.edu Institute For Astronomy kleka@susolar.bitnet University of Hawaii DISCLAIMER: " don't blame me, I'm just a grad student! " ------------------------------ Date: 16 Jan 91 14:48:56 GMT From: eru!hagbard!sunic!fuug!tuura!urbanf@bloom-beacon.mit.edu (Urban Fredriksson) Subject: Re: Cameras in 0G, was: Re: MIR Vacation fiddler@concertina.Eng.Sun.COM (Steve Hix) writes: >In article <92@hobby.ukc.ac.uk>, has@ukc.ac.uk (H.A.Shaw) writes: >> >> Whats all this about modifications for 0G? [...] >> [...] I have around 20,000 slides in my current collection and I've never >> knowingly lost a shot because of gravity. What difference does gravity make? >As I (dimly) recall, space-rating a camera system has little do with >gravity. The problems that concerned NASA had more to do with the >cameras operation in vacuum (outgassing, lubrication, thermal response, >etc.) than anything else. Some chemicals outgassing from the camera >might have been a potential problem from a life-support angle, and >evaporating lubricants could leave you with a non-functioning paperweight >just when you didn't need one. You will also want all the electrical sections VERY isolated, so that there is no chance of a spark starting a fire. An other safety-related thing is shock-proofing. If I remember correctly the camera had to withstand 3 50G shocks, in different axes, without any parts becoming separated. The limit for keeping it in working condition was 10G. Urban ------------------------------------------------------------------- | Urban Fredriksson | "So; you think he deserves to die. | | Nokia Data, Stockholm | Those who died, but deserved to | | These opinions are mine, | live, can you give them life back?" | | not my organization's. | -attributed to Gandalf | ------------------------------------------------------------------- ------------------------------ Date: 16 Jan 91 22:30:50 GMT From: agate!bionet!uwm.edu!wuarchive!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucbvax.Berkeley.EDU (Ron Baalke) Subject: Magellan Update - 01/16/91 MAGELLAN STATUS REPORT January 16, 1991 The Magellan spacecraft and its radar system continue to perform nominally after 796 mapping orbits. All STARCALS (star calibrations) and DESATS (desaturations) during the past 24 hours were successful. No commanding of the spacecraft is planned for today. The spacecraft telemetry reported some attitude reference alarms last night. There was a "miscompare" between the sun sensors in that the location of the sun as indicated by the two sensors did not match and/or varied from the reference value in the on-board computer. This is believed to be an albedo effect of Venus, and is being studied further. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 15 Jan 91 20:42:46 GMT From: agate!linus!linus!kurgen!sokay@ucbvax.Berkeley.EDU (Steve Okay W43) Subject: CRRES observations from Wash. D.C. Did anybody in the Washington D.C. area get a good glimpse of the CRRES releases? A bunch of us took up station at the Manassas National Battlefield Park last night from about 10:50 'till 12:30 and didn't see anything (well, the stars were out, but nothing even remotely tenuously glowing or otherwise non-stellar. There were about 6-8 of us facing in all different directions, so I don't think it was a problem of not looking in the right direction. It was pretty clear out for almost the entire viewing attempt. Some light pollution, but I didn't feel like taking the hike out to Marshall or Rt. 81 to get away from all of it. (This could have done it). If you were anywhere in the D.C. area and saw something, could you mail me and tell me where and when you were and what you saw? Thanks, ---Steve ----------- sokay@mitre.org <---work steve%amidillo.uucp@uunet.uu.net <---home ------------------------------ End of SPACE Digest V13 #054 *******************