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 ; Tue, 3 Apr 90 02:47:58 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 3 Apr 90 02:47:32 -0400 (EDT) Subject: SPACE Digest V11 #211 SPACE Digest Volume 11 : Issue 211 Today's Topics: Re: Will we lose another orbiter? Payload Summary for 03/30/90 (Forwarded) RE: SPACE Digest V11 #178 Re: Comparative Costs to LEO Velikovsky's Theory JUNK IN SPACE ---------------------------------------------------------------------- Date: 29 Mar 90 19:16:58 GMT From: samsung!cs.utexas.edu!hp-sdd!ncr-sd!ncrlnk!ncrcce!ncrons!johnson@think.com (Wayne D. Johnson) Subject: Re: Will we lose another orbiter? In article <6927@timbuk.cray.com> lfa@timbuk.cray.com (Lou Adornato) writes: => One of the root causes of the Challenger accident, was public pressure =>to launch on schedule. This was caused by the public's inability to understand just =>how complex and demanding launching an experimental aircraft can be. Once people =>stop taking technology for granted, they start learning. Maybe in the long run Challenger =>will have made us stronger by making us see the danger in having 90% of our population =>(and 100% of our policy makers) technologically illiterate. I disagree. It was not public pressure that was forcing NASA to fudge on safety It was NASA's impression of congress's impression of the public. Both impressions probably are faulty (IMHO). =>In the light of basic probability, I don't see how a lower "risk" factor can be justified. => =>Consider a single component with a reliability of 99.9999% (which is pretty good even =>for a small, simple component, like a rivet). The chance of this part failing is =>one in 10,000. If there are 1000 of these parts, then there is 1 chance in 10 that =>one of them will fail. If you put a million of them into the system, then you have =>to expect that 100 of them _will_ fail. In order to maintain a 98% safety margin, you =>have to increase the per-unit reliability by _three_ orders of magnitude. Do you have =>any idea how to make a rivet 1000 times more reliable? Keep in mind that making it heavier =>might reduce the reliability of some other component. That is assuming that the mission will fail if any of the parts fail. The main reason for redundant systems is to limit the failure rate by increasing the number of parts that may fail. By having 3 redundant engines, failure of 1 critical part in 1 engine will not cause a "failure". You probably know all of this, I'm just thinking out loud. =>Yes, they should, no smileys about it. Basic spares management policy would be to have =>a new orbiter ready after 50 flights (25 would be better), and then put it in "hot" storage It might be a good idea to think about updating the design to start removing some of the risks as we are building a new shuttle. -- Wayne Johnson | Is a baby's life worth more than the right to NCR Comten, Inc. | make a choice? Babies are people too. Roseville MN 55113 +----------------------------------------------------- (Voice) 612-638-7665 (E-MAIL) W.Johnson@StPaul.NCR.COM ------------------------------ Date: 31 Mar 90 14:24:13 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Payload Summary for 03/30/90 (Forwarded) Payload Status Report Friday, March 30, 1990 George H. Diller NASA Kennedy Space Center HUBBLE SPACE TELESCOPE The installation of the telescope into the payload canister was completed on Friday, Mar. 23. Transportation of HST on the ten-mile trip from the Vertical Processing Facility to launch pad 39-B began just after midnight on Sunday morning, Mar. 25. It arrived at the pad at dawn. Removal of the protective cocoon from around the telescope and opening of Discovery's payload bay doors was rescheduled by one day to Tuesday, Mar. 26, to deal with insects. Midges, an insect resembling a small mosquito, was observed on the payload bay doors of the orbiter. Some escaped into the payload changeout room. Those remaining were vacuumed off. Seven traps were placed in the PCR. Collectively, a total of 40 midges were removed from the facility. Because the cocoon remained in place around HST there was no path for the midges to enter the telescope. The cocoon removal did not begin until traps provided confidence that there was not additional risk. At 4:30 a.m. on Wednesday, Mar. 28, the traps were removed. Telescope installation was rescheduled for one day later to schedule crews and permit some Space Shuttle ordnance work to be accomplished. The transfer of the Hubble Space Telescope into the payload bay of Discovery began at 10:40 a.m. on Thursday, Mar. 29. The HST was locked into the first of four payload bay retention latches at 3:55 p.m. and into the last latch at 4:40 p.m. Electrical connections were established between the HST and the orbiter overnight and this morning, leading to a 6.5 hour Interface Verification Test scheduled to begin at the start of on second shift at 4:00 p.m. to verify those connections. At midnight on Sunday morning, Apr. 1, a 52-hour of Pad Confidence Test will begin as a final check of the telescopes's systems and its onboard science instruments. These tests will also verify remote communications capability to the Space Telescope Operations Control Center (STOCC) at NASA's Goddard Space Flight Center in Greenbelt, Md., the Huntsville Operations Support Center (HOSC) at the Marshall Space Flight Center in Huntsville, Alabama, and the Lockheed plant at Sunnyvalve, Calif. The STOCC will be able to receive data and send commands through Discovery's communications systems which are connected to the Hubble Space Telescope in the payload bay. The HOSC and Lockheed Sunnyvale will be monitoring the spacecraft systems. The final work to be performed will be approximately 132 hours of battery charging scheduled to be completed 68 hours before launch, after which the payload bay doors of the orbiter are to be closed. GAMMA RAY OBSERVATORY Weight and center of gravity measurements have been completed to determine whether any refinements need to be made. Observed offsets will be compensated for by repositioning the orbit adjust thrusters or by ballasting certain locations of the spacecraft. Testing with the Payload Operations Control Center (POCC) at the Goddard Space Flight Center was completed late Tuesday. These tests simulated procedures to be used later when GRO is in the payload bay of Atlantis, and again for a predeployment checkout exercise. As part of this exercise, all science instruments were operated during the "34 Hour Test." This was essentially an end-to-end test which allowed data flows to be sent to science investigators at other NASA centers or laboratories which sponsor one of the GRO instruments. Also part of the exercise was a test of the Ephemeris program and associated spacecraft computers. This was two consecutive software loads of a program which deals with the predicted orbital characteristics of the Gamma Ray Observatory. This is used by the satellite to control certain on-orbit spacecraft activities based on the satellite's geographic location. Trouble shooting became necessary early in the test to resolve issues with computer updates of internal clock software; however, this allowed engineers to perform and complete the test successfully. Portions of this test may be repeated later. Yesterday, checks began of the other onboard computer software. These programs were used during functional testing of the observatory's instruments, and the software associated with them can now be refined. PAYLOAD STATUS REPORT FRIDAY, MAR. 30, 1990 Patricia E. Phillips NASA Public Affairs, Kennedy Space Center ASTRO-1/STS-35 (OPF) The ASTRO-1 astrophysics payload has successfully completed an extensive series of testing in Columbia's payload bay. The test team moved smoothly through the Crew Equipment Integration Test (CEIT), the interface verification test (IVT), and the end- to-end test. The series of tests confirmed that communications between orbiter and payload are operational, as are communica- tions between orbiter, payload, KSC, Marshall Space Flight Center, Goddard Space Flight Center, Johnson Space Center, and satellite relays. During the testing, a signal conditioning box that handles data between the orbiter and the payload experienced a failure of one circuit. This box, called a Remote Amplifier and Advisory Box (RAAB), immediately switched to its redundant circuit, and test- ing was completed without any impact. Following completion of testing, engineers and managers decided to replace the unit, which is housed near the top of the ASTRO-1 igloo. The "remove and replace" procedure was worked overnight Mar. 28/29. Operations went so smoothly that retests of the new RAAB and its linkages were underway by 4 a.m. Mar. 29 and completed that same day. Pre-flight processing for ASTRO-1 will include regularly- scheduled BBXRT servicing, as well as continued contamination control and temperature monitoring. SPACELAB LIFE SCIENCES (SLS-1)/STS-40 (O&C Building) The floor assembly and racks were moved to Test Stand 2 on Mar. 29 in preparation for integration there with the Spacelab module. The integration is scheduled to begin Monday. STS-40 Mission Commander Bryan O'Connor was on hand Mar. 29 as technicians began moving the components to Test Stand 2. The combination of moving elements and integration with the module will take several days. A replacement for a low-G centrifuge that experienced tem- perature fluctuations was installed. The new unit, an upgraded one, successfully passed retesting. SLS-1 will be launched in August aboard Columbia. INTERNATIONAL MICROGRAVITY LABORATORY (IML)/STS-42 (O&C Building) Technicians continue the buildup and integration of com- ponents and racks for IML, scheduled to fly aboard Columbia in December. An international mission, IML will have a crew of seven. Five international space science research organizations are work- ing with NASA on IML: the European Space Agency (ESA), the Canadian Space Agency (CSA), the French National Center for Space Studies (CNEW), the West German Research and Development In- stitute for Air and Spacecraft (DLR), and the National Space Development Agency of Japan. ------------------------------ Date: Sat, 31 Mar 90 23:37 EST From: CCUWINT%INDSVAX1.BITNET@vma.cc.cmu.edu Subject: RE: SPACE Digest V11 #178 How can I be removed from this list? The mail is overwhelming my account! HELP! Don Winters ------------------------------ Date: 1 Apr 90 03:13:13 GMT From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@decwrl.dec.com (Henry Spencer) Subject: Re: Comparative Costs to LEO In article <651@idacrd.UUCP> mac@idacrd.UUCP (Robert McGwier) writes: >If the world wanted to put stuff in a 250km high, 28 to 58 degree inclination >orbit, your numbers would be meaningful. Since BY FAR, most of the >LEO shots are polar... Um, you've forgotten a goodly assortment of science missions -- e.g. the Hubble telescope -- which merely want to get into orbit and don't greatly care which orbit. Space is not just comsats and spooks. -- Apollo @ 8yrs: one small step.| Henry Spencer at U of Toronto Zoology Space station @ 8yrs: .| uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 28 Mar 90 21:51:15 GMT From: eru!luth!sunic!mcsun!ukc!reading!cf-cm!cybaswan!iiitsh@bloom-beacon.mit.edu (Steve Hosgood) Subject: Velikovsky's Theory As many of you probably know, a guy called Immanuel Velikovsky published a couple of books in the 1950's entitled "Worlds in Collision" and "Ages in Chaos". Maybe he wrote others too - it's not important. He postulated that several times in recent (i.e recorded) history, the orbits of Mars and Venus were disturbed wildly, and those planets came in close contact with the earth. The resulting tidal forces, and spin changes and orbit changes for the earth caused such legends as the Biblical flood and others to be written - based on fact. Indeed, unless he does a serious lying job, it seems that many cultures have a flood myth, and many claim that the sun stopped in its tracks one day (or maybe that the night was very long if they were on the other side of the planet). Things are quieter these days, and it seems highly unlikely that Mars or Venus should have strayed from their orbits. However, it seems that current thoughts are that the planetary orbits are chaotic in nature (mathematically chaotic, that is), and maybe in the light of this , strange things could have happened once or twice. Maybe they will happen again, though the nature of chaos probably prevents a sensible prediction. Certainly, Venus has a retrograde spin, and it seems Mars *may* have had running liquids on its surface recently enough that the sandstorms have not yet removed the evidence. Both of these facts seem a bit odd, yet are known to be true. Has Velikovsky's theory held up under attack from supercomputer simulations in recent years? Any info? Enquiring minds would like to know. THanks for your time reading this. Steve iiitsh@pyr.swan.ac.uk or iiitsh@cybaswan.uucp ------------------------------ Date: 2 Apr 90 06:36:17 GMT From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!fmgst@tut.cis.ohio-state.edu (Filip G.) Subject: JUNK IN SPACE Greetings. I have heard a few times that man has launched so many sattelites and other "junk" into orbit that, in the future, there might be problems with having collisions. And, in my humble opinnion (IMHO), things are getting worse. For example, correct me if I'm wrong, do the NASA people have to worry about "unexpected", old, non-functional, satellites "tumbling" to earth in a collision path with a newly deployed satellite. It seems to me that instead of building a space station, NASA should worry about "cleaning up" the earth's orbit and not "polluting" it more. Also, in the news, I heard that the "promised" space station would require billions in maintenance. Are those expenses due to all that "junk" in space, or particles of thereof? Please correct me if I'm wrong, but the only "safe" way to exist in space for any period of time would be to "quickly" invent/implement a "force" field or shield. (Like StarWars or StarTrek...:-) Tell me what you think... fmgst@unix.cis.pitt.edu -- _______________________________________________________________________________ "The FORCE will be with you. Always." It *IS_ with me and has been for 8 years. Filip Gieszczykiewicz "..of future fame...." "Ok! so I have a dream..." FMGST@PITTVMS or fmgst@unix.cis.pittsburgh.edu ------------------------------ End of SPACE Digest V11 #211 *******************