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 ; Mon, 11 Mar 91 02:35:25 -0500 (EST) Message-ID: <4bqnAsS00WBwA1pE49@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 11 Mar 91 02:35:20 -0500 (EST) Subject: SPACE Digest V13 #258 SPACE Digest Volume 13 : Issue 258 Today's Topics: Navstar GPS Constellation Status (91-03-09) Re: Gaia [l/m 7/11] Frequently asked SPACE questions SOLAR TERRESTRIAL BULLETIN - 10 MARCH (SOLAR UPDATE) cause of shuttle disaster space news from Jan 28 AW&ST 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: Sat, 09 Mar 91 09:37:54 AST From: LANG%unb.ca@UNBMVS1.csd.unb.ca Subject: Navstar GPS Constellation Status (91-03-09) Navstar GPS Constellation Status (91-03-09) Blk NASA Orbit Launch II PRN Internat. Catalog Plane Date Seq SVN Code ID Number Pos'n (UT) Clock Comment -------------------------------------------------------------------------------- Block I 1 4 1978-020A 10684 78-02-22 Not usable since 85-07-17 2 7 1978-047A 10893 78-05-13 Not usable since 81-07-16 3 6 1978-093A 11054 A-3 78-10-06 Rb Usable as of 78-11-13 4 8 1978-112A 11141 78-12-10 L-band signals turned off 89-10-14 5 5 1980-011A 11690 80-02-09 Not usable since 83-11-28 6 9 1980-032A 11783 80-04-26 L-band signals permanently turned off 91-03-06 7 81-12-18 Launch failure 8 11 1983-072A 14189 C-3 83-07-14 Cs Usable as of 83-08-10 9 13 1984-059A 15039 C-1 84-06-13 Cs Usable as of 84-07-19 10 12 1984-097A 15271 A-1 84-09-08 Cs Usable as of 84-10-03 11 3 1985-093A 16129 C-4 85-10-09 Rb Usable as of 85-10-30 operating on Rb clock without temp. control Block II II-1 14 14 1989-013A 19802 E-1 89-02-14 Cs Became available 89-04-15 II-2 13 2 1989-044A 20061 B-3 89-06-10 Cs Became available 89-08-10 II-3 16 16 1989-064A 20185 E-3 89-08-18 Cs Became available 89-10-14 II-4 19 19 1989-085A 20302 A-4 89-10-21 Cs Became available 89-11-23 II-5 17 17 1989-097A 20361 D-3 89-12-11 Cs L-band signals enabled 90-01-06 II-6 18 18 1990-008A 20452 F-3 90-01-24 Cs Became available 90-02-14 22:26 UT II-7 20 20 1990-025A 20533 B-2 90-03-26 Cs Became available 90-04-18 23:13 UT II-8 21 21 1990-068A 20724 E-2 90-08-02 Cs Became available 90-08-22 15:00 UT II-9 15 15 1990-088A 20830 D-2 90-10-01 Cs Became available 90-10-15 00:39 UT Block IIA II-10 23 23 1990-103A 20959 E-4 90-11-26 Cs Became available 90-12-10 23:45 UT Notes 1. NASA Catalog Number is also known as NORAD or U.S. Space Command object number. 2. No orbital plane position = satellite no longer operational. 3. Clock: Rb = Rubidium; Cs = Cesium 4. Earlier versions of this table had incorrect end-of-service dates for PRNs 7 and 5. 5. PRN 6 may experience problems during its eclipse season due to poor battery performance. ============================================================================== Richard B. Langley BITnet: LANG@UNB.CA or SE@UNB.CA Geodetic Research Laboratory Phone: (506) 453-5142 Dept. of Surveying Engineering Telex: 014-46202 University of New Brunswick FAX: (506) 453-4943 Fredericton, N.B., Canada E3B 5A3 ============================================================================== ------------------------------ Date: 10 Mar 91 05:57:28 GMT From: munnari.oz.au!metro!socs.uts.edu.au!dcorbett@uunet.uu.net (Dan Corbett) Subject: Re: Gaia lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) writes: >In article <9103020230.AA06812@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >: What part of Gaia is its appendix? :-) >Hmm, something that uses resources but doesn't contribute to the good of >the whole, and is, in fact, occasionally destructive? I'll have to >think about that one... :-) Politicians? ------------------------------------------------------------------------------ Dan Corbett Department of Computer Science University of Technology, Sydney Sydney, New South Wales, Australia ------------------------------------------------------------------------------ ------------------------------ Date: 10 Mar 91 12:01:08 GMT From: eagle!data.nas.nasa.gov!amelia!eugene@ucbvax.Berkeley.EDU (Eugene N. Miya) Subject: [l/m 7/11] Frequently asked SPACE questions This list does change. Slowly. It only changes when the members of s.s. have something to add, correct, etc. I no longer have time to read s.s., and the SNR is too low. So if this does not change it is more a reflection of the other people you are reading, and not me. Think about that for a moment. You make the difference. "It's not a message. I think it's a warning." -- Ripley This is a list of frequently asked questions on SPACE (which goes back before 1980). It is developing. Good summaries will be accepted in place of the answers given here. The point of this is to circulate existing information, and avoid rehashing old answers. Better to build on top than start again. Nothing more depressing than rehashing old topics for the 100th time. References are provided because they give more complete information than any short generalization. Questions fall into three basic types: 1) Where do I find some information about space? Try you local public library first. You do know how to use a library, don't you? Can't tell these days. The net is not a good place to ask for general information. Ask INDIVIDUALS if you must. There are other sources, use them, too. The net is a place for open ended discussion. 2) I have an idea which would improve space flight? Hope you aren't surprised but 9,999 out of 10,000 have usually been thought of before. Again, contact a direct individual source for evaluation. NASA fields thousands of these each day. 3) Miscellanous queries. Sorry, have to take them case by case. Initially, this message will be automatically posted once per month and hopefully, we can cut it back to quarterly. In time questions and good answers will be added (and maybe removed, nah). 1) What happen to Saturn V plans? What about reviving the Saturn V as a heavy-lift launcher? Possible but very expensive -- tools, subcontractors, plans, facilities are gone or converted for the shuttle, and would need rebuilding, re-testing, or even total redesign. 2) Where can I learn about space computers: shuttle, programming, core memories? %J Communications of the ACM %V 27 %N 9 %D September 1984 %K Special issue on space [shuttle] computers %A Myron Kayton %T Avionics for Manned Spacecraft %J IEEE Transactions on Aerospace and Electronic Systems %V 25 %N 6 %D November 1989 %P 786-827 Other various AIAA and IEEE publications. Computers in Spaceflight: The NASA Experience James E. Tomayko 1988? 3) SETI computation articles? %A D. K. Cullers %A Ivan R. Linscott %A Bernard M. Oliver %T Signal Processing in SETI %J Communications of the ACM %V 28 %N 11 %D November 1984 %P 1151-1163 %K CR Categories and Subject Descriptors: D.4.1 [Operating Systems]: Process Management - concurrency; I.5.4 [Pattern Recognition]: Applications - signal processing; J.2 [Phsyical Sciences and Engineering]: astronomy General Terms: Design Additional Key Words and Phrases: digital Fourier transforms, finite impulse-response filters, interstellar communications, Search for Extra-terrestrial Intelligence, signal detection, spectrum analysis You can make it change. Just discuss the changes on the net, then mail the resolution to me. ------------------------------ Date: Sun, 10 Mar 91 01:30:02 MST From: oler%HG.ULeth.CA@vma.cc.cmu.edu (CARY OLER) Subject: SOLAR TERRESTRIAL BULLETIN - 10 MARCH (SOLAR UPDATE) X-St-Vmsmail-To: st%"space+@andrew.cmu.edu" /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ SOLAR TERRESTRIAL BULLETIN 10 March, 1991 Updated Solar Activity Information /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ UPDATED SOLAR ACTIVITY INFORMATION No major flares occurred on 09 March, although significant spot activity has been observed in Region 6538. This region, which was the source of strong solar activity on 07 March has become slightly more compact. Spots within this region have increased from 63 on 09 March to 107 on 10 March. High levels of shear still appear to exist in this region. Some magnetic complexity is also apparent in this beta-gamma system. Region 6538 is now centered at a location of S23E32 and is now capable of producing moderate to high terrestrial impacts if a significant major solar flare erupts. Proton activity won't be a real threat until after 12 or 13 March. However, geomagnetic and auroral impacts could be high if a strong solar flare erupts anytime between now and approximately 18 or 19 March. Proton impacts will be possible until after this region passes beyond the west limb, which is expected sometime near 20 March. PCA activity will also be possible anytime after about 13 March until near 20 March. A 245 MHz solar radio noise storm was in progress throughout all of 09 March. This noise storm is most likely associated with Region 6538, which has shown some high spot activity recently. Major flaring is still expected to occur from Region 6538. Major M-class flaring is likely to be observed. Isolated major X-class flares are also possible. Minor M-class flaring is a certainty from this region. Flare sizes could still reach a 3B optical rating. Minor to major geomagnetic storming has been observed several times during the UT day on 09 March over high latitudes. Activity increased to major storm levels over the high latitudes at approximately 01:50 UT on 10 March. Activity has since subsided somewhat, although pulses of minor to major magnetic storming is still expected to occur over the high latitude regions over the next 24 hours. Middle latitudes have experienced a couple of brief periods of minor geomagnetic storming. However, overall activity has not yet surpassed storm level thresholds over the middle latitudes. A sudden magnetic impulse was observed over middle latitude magnetic observatories at 22:46 UT on 09 March. The intensity of this SI ranged from approximately 30 to 45 gammas. Low to moderate intensity minor storming was observed over middle latitudes between 01:50 UT and 05:30 UT on 10 March. However, no significant rapid magnetic excursions were observed with this activity. The geomagnetic field over the middle latitudes has declined to generally very active levels. Minor storm periods are still possible (if not expected). Auroral activity increased after 01:30 UT on 10 March. Moderate auroral activity was observed over middle latitude regions. The auroral oval has shifted optically southward. The leading edge of the oval was measured to be at an elevation of approximately 50 degrees above the northern horizon at N49W112. A diffuse auroral arc was the primary activity observed during the observation. No further significant migration of the auroral oval is expected over the next 24 hours. Migration back to the higher latitudes will occur on 11 and 12 March. Overall geomagnetic and auroral activity will subside on 12 March (barring any significant solar activity). HF radio signals have suffered some degradation due to the recent burst of geomagnetic and auroral activity. Areas most heavily affected are the high latitudes and northerly middle latitudes. Radio signal paths which enter or cross through the auroral zone (ex. polar or high latitude paths) have experienced moderate fading and increased absorption. Auroral flutter is very apparant in the high and middle latitude signals. So far, the flutter fading has not been too intense (judging by the reports received so far). VHF auroral backscatter communications may be possible over the northerly middle and high latitude regions. Best opportunities for DX contacts exist using CW. Please report any DX contacts on the VHF bands to "oler@hg.uleth.ca". And again, reports of auroral activity sightings can also be directed to the above address. Thanks, to all those who send in reports. ** End of Bulletin ** ------------------------------ Date: 10 Mar 91 15:12:18 GMT From: zaphod.mps.ohio-state.edu!samsung!news.cs.indiana.edu!nstn.ns.ca!Iris1.UCIS.Dal.Ca!roberts@tut.cis.ohio-state.edu (Greg Roberts) Subject: cause of shuttle disaster I have watched this thread of discussion about two 'high level' engineers and their claim about the cause of the accident. I suggest that for anyone interested in the facts, they obtain Volume 1 of the Presidential Commission on the Space Shuttle Challenger accident, and look at the photographs on pages 22 - 36 and 74 - 81. The strut failure is a nice theory, but has no photographic evidence to support it. What the photographic (still and video) does support is exhaust gas erosion of the ORing, which caused a hole in the SRB casing. This resulted in hot exhaust gas burning the insulation on the ET, and causing a rupture. It was the combustion of the contents of the ET causing the severe loading on the shuttle. The strut broke because the lower attach point gave way from the weakened ET causing it to rotate about the support. I would like to see the 'evidence' cooked up by these two. Did they appear at the Rogers Commission to testify? Do they have any materials testing reports, independent photographic analysis, fatigue analysis or the like to support their claim? Enquiring, although seriously skeptical minds, want to know. ------------------------------ Date: 11 Mar 91 06:38:45 GMT From: news-server.csri.toronto.edu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: space news from Jan 28 AW&ST Amroc proposes Aquila, a four-stage hybrid launcher for Motorola's Iridium mini-comsat network, claiming 1500lbs to 300nmi at about half the cost of current alternatives. ESA declares Ulysses fully operational. Space insurance rates expected to rise after circa $200M losses on recent in-orbit satellite failures. USAF Space Command has set up special data links to get data from missile- warning satellites directly to Patriot batteries nearly in real time. This plus other measures to improve communications have boosted warning time for Scud attacks to nearly 5min from 90-120s. Warning-satellite officials say Iraq's Scud tests late last fall were serious blunders, because they gave the US a priceless opportunity to debug the warning setup before it was needed in combat. Final design details have been settled for the field joint of the ASRM. The new joints are bolted together, the O-rings remain visible as the joint is mated, and the joint is designed to close up under pressure rather than opening. Looking at the diagram, inboard of the bolts the joint is two flat flanges touching each other, and two O-rings are set into the surface of the lower flange near the inner edge. The upper flange goes to the edge of the lower flange and then turns downward around it, with a third O-ring set into the outer surface of this lip, seating against the inner edge of the lower flange. Another major ASRM design change is careful design of the internal shape of the fuel so that thrust drops off somewhat for a brief period early in the flight, eliminating the need for the SSMEs to throttle back during the period of maximum dynamic pressure. This eliminates assorted possible failure modes related to throttle-back and the following throttle-up. Other changes include a revised casing design that has fewer assembled parts, one less field joint, welded factory joints, and better steel; a simpler nozzle design eliminating assorted joints and seals; and a redesigned igniter. Finally, a lighter casing, a larger diameter holding more fuel, and a slightly more energetic fuel give higher thrust, longer burn, and about 18% more shuttle payload. An important change unrelated to the booster design is the shift to highly automated manufacturing, since each handling step increases the odds of trouble. [Another aspect of this, not mentioned, is that the ASRM plant at Yellow Creek will be NASA-owned, so NASA will be less tied to a single contractor and can exert more control.] ASRM still has its critics, however. Some say the $971M would be better spent elsewhere, especially on the SSMEs and on incremental improvements to the existing boosters (since ASRM is still five years away). There is the possibility of political pressure to shift money to heavylift boosters, and concerns about the environmental effects of the rather "dirty" solid fuels. Finally, there is still strong skepticism in some areas about the safety of manned flight on solid boosters, given the sensitivity to manufacturing flaws and the impossibility of test-firing. Cost considerations are likely to preclude abandoning SRBs, however. [That's it for space news in this AW&ST. They are rather preoccupied with other current events... However, here's a *very* interesting bit from the 15 Feb issue of Science:] Congress is very interested in the Augustine commission's recommendation for a heavylift launcher, and there is starting to be specific interest in one particularly heavylift launcher... the Saturn V!! Truly, questioned about the matter, says the plans still exist. It's pretty obvious, though, that NASA would really prefer a shuttle-derived launcher. Congress may pursue the matter, although there is the obvious problem that tooling is gone and many subcontractors are gone, so resurrecting the Saturn V would be costly. -- "But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology for the general public." -S. Harris | henry@zoo.toronto.edu utzoo!henry ------------------------------ End of SPACE Digest V13 #258 *******************