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, 18 Nov 89 01:35:29 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 18 Nov 89 01:34:57 -0500 (EST) Subject: SPACE Digest V10 #260 SPACE Digest Volume 10 : Issue 260 Today's Topics: Re: deadliness of environments NIST space conference HST resolution Re: HST resolution Looking Down [was: Re: HST resolution] Payload Status for 11/17/89 (Forwarded) Re: Hubble Space Telescope Re: Looking for US launcher family tree Re: Mars space elevator ---------------------------------------------------------------------- Date: 16 Nov 89 15:01:00 GMT From: cs.utexas.edu!usc!samsung!uakari.primate.wisc.edu!uwm.edu!wuarchive!texbell!merch!cpe!hal6000!trsvax!reyn@tut.cis.ohio-state.edu Subject: Re: deadliness of environments >Given a certain level of basic technology, space is actually a fairly benign place;< I am curious to here what you consider "basic technology". In the wilds of Antartica, the "basic technology" necessary to conserve heat, obtain water, and breath is supplied to every human child by its mother. Food gathering is a bit more complicated, you generally have to locate a rock or a big stick. Please don't underestimate the massive amount of infrastructure which will be necessary to produce a sustainable space colony. EMphasis on the word sustainable. Projects such as Biosphere II in Arizona are but a modest step in the general direction towards self-sufficient artificial ecosystems. Life is infinitely adaptable, and I've no doubt that organisms will evolve to fill every possible niche, I'm not so sure that our organism will be one of them. Space is not a panacea. When "we" get there, "we" will be the same squabling lot of ego-centric beings that we are now. With life support sytems on which all of "our" lives depend on, government will become more stringent, not less. Responsibility of the individual to the whole will increase, not decrease. The "throw away" society will perish or its members will fade away. When those guys walked across the land bridge from Siberia to America, they really could just run off in the woods and "go native". Neil Armstrong didn't have that option. ------------------------------ Date: Fri, 17 Nov 89 20:32:40 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: NIST space conference (Somebody posted a request for more information a few weeks ago. This notice was distributed to all employees today.) NIST Conference On REDUCING THE COST OF SPACE INFRASTRUCTURE AND OPERATIONS November 20-22, 1989 National Institute of Standards and Technology (formerly National Bureau of Standards) Gaithersburg, MD Sponsored by: NIST Office of Space Commerce/DOC The Space Foundation AGENDA Monday, November 20, 1989 Orbital Facilities and EVA Session: (Co-chairman: Thomas F. Rogers, ETCO, and Dr. Bill Stone, NIST) Spacehab Shuttle Module James Beggs, SpaceHab, Inc. Industrial Space Facility Dr. Maxime Faget, Space Ind., Inc. Space Phoenix Project Thomas F. Rogers, Sophron Foundation External Tank Habitat Dr. Randolph Ware, ETCO Aquarius Habitat Glen Taylor, NOAA Hardsuits, ROVs Phil Nuytten, Candive Services, Ltd. Hypobaric Physiology Dr. R.W. Hamilton, Hamilton Res., Ltd. Chemical Launch Vehicle Session: (Chairman: Rich Dalbello, Office of Space Commerce, DOC) Hybrid Booster Jay Kniffen, AMROC Air-Launched ELVs Dr. Robert Lindberg, OSC u-Sats & Secondary Payloads Douglas Heydon, Arianespace Novel Integration Concepts Ed Bock, General Dynamics Tuesday, November 21, 1989 Payloads and Institutional Aspects Session: (Chairman: Dr. Cary Gravatt, NIST) Robotics and Automation Joe Engleberger, Transition Research Small Satellite Experience Ball Aerospace Payload Sensors Carl Schueler, Hughes SBRC Small Compartment Costs Helmut Hellwig, NIST Risk Factors & Insurance John Cozzi, Carroon & Black Inspace Technology Transfer Mike Miller, C.I.T. Quality and Cost Curt Reimann, NIST Advanced Launch Vehicle Session: (Chairman: Ray Williamson, OTA) NASP Mike Weeks, NASA Shuttle-C Vehicle Ed Gabris, NASA Laser Assisted Launch Dr. Jordin Kare, Livermore Nat'l Labs. Ram Accelerator Dr. Abe Hertzberg, Univ. of Wash. Space Ship Experimental Steve Hoeser, General Research Corp. Wednesday, November 21, 1989 Summary Session: Orbital Facilities Thomas F. Rogers, ETCO EVA Dr. Bill Stone, NIST Chemical Launch Vehicles Rich Dalbello, Space Commerce, DOC Payloads & Inst. Aspects Dr. Cary Gravatt, NIST Advanced Launch Vehicles Ray Williamson, OTA [NOTE: I don't have anything to do with this - I just work here (in the computer research lab). I'll try to sit in on some of the sessions if my boss will let me. Any recommendations/requests?] John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: Fri, 17 Nov 89 19:00:45 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: HST resolution >From: cs.utexas.edu!samsung!aplcen!haven!uvaarpa!hudson!astsun9.astro.Virginia.EDU!gsh7w@tut.cis.ohio-state.edu (Greg S. Hennessy) >Subject: Re: Hubble Space Telescope >The resolution of HST is [roughly] 20 milliarcseconds. Let us consider >Alpha centuri. It is about 1.3 parsecs away, this 1 arcsecond will be >1.3 AU or about 130 million miles. 20 mas will be about 26 million >miles. This is about 100 times the earth moon distance. I would >consider it rather awful reporting myself. ....................... >>, allanb@ronin.us.cc.umich.edu (Allan M. Bjorklund) writes: >> >> I redid the calculations, and came up with the HST being able >> to resolve a 3000 mile wide object at 39 AU which is about 5.3 light >> hours, which is the distance to Pluto. But unfortunately, Pluto is only >> about half that in diameter. There have been several calculations similar to this posted recently, and most of them seem to be off (with respect to my calculations) by roughly a factor of 1.5-2. My reasoning is as follows: With 60 seconds of arc in an arcminute, 60 minutes in a degree, and 360 degrees in a full circle, an angle of 20 milliarcseconds makes up 1/10800000 of a full circle. To determine the width of the projection of a small angle at a given distance, you can compute the length of the corresponding arc along the circumference of a circle at that distance, or the height of a right triangle with the given angle and the base equal to the distance. These will be very close because the angle is extremely small. To compute the arc, the total circumference of the circle is 2 * pi * d, so the length of the arc will be 2 * pi * d / 10800000. To compute the height of the triangle, use the formula h = sin(theta) * base. Since for very small angles, the sine of an angle (in radians) is very close to the value of the angle itself, and the angle is 2 * pi / 10800000, the height is approximately 2 * pi * d / 10800000. Thus, by both of these methods, the width of the projection ~= d * 5.818E-7. Applying this formula to the two reference equations, the resolution at 1.3 parsecs (at 1 parsec = 206265 AU), is about 14.5 million miles, and the resolution at 39 AU is about 2100 miles. Would someone please check the figures? I may have misinterpreted some of the initial assumptions. It is my impression that the intended method for location of large planets around stars is to use spectroscopy to look for periodic redshift/blueshift of the light from the stars, corresponding to the wobble caused by the influence of the large planets. This would require observation over a considerable fraction of such a planet's path around its star, which could take several Earth years. John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 18 Nov 89 01:56:59 GMT From: rochester!dietz@pt.cs.cmu.edu (Paul Dietz) Subject: Re: HST resolution In article <8911180000.AA03391@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >It is my impression that the intended method for location of large planets >around stars is to use spectroscopy to look for periodic redshift/blueshift >of the light from the stars, corresponding to the wobble caused by the >influence of the large planets. This would require observation over a >considerable fraction of such a planet's path around its star, which could >take several Earth years. Spectroscopy is one technique. Another is astrometry. There has been some work on high precision astrometry using ground-based scopes by Gatewood in Pittsburgh. He has a nice instrument that uses a Ronchi ruling to accurately measure the angular separation between stars. Accuracies in the milliarcsecond range can be achieved from the ground, given enough time. As you would expect, from space you can do a whole lot better. The Astrometric Telescope Facility (?) would cost maybe $200-300 M. It could achieve resolution in the *micro* arc second range -- on the order of the angle subtended by an atom held at arms length! Jupiter-sized planets would be detectable by this instrument out to thousands of light years; even the motion due to earth-sized planets could be detected for nearby stars. NASA was trying to get the ATF put on the space station -- a perversion of science, IMHO. The thing should obviously be a free-flyer -- a vibrating space station is no place for such a sensitive instrument. Since the station was scaled back, there's no place to put the ATF, and I haven't heard anything about it, so it's probably been knifed. An aside -- I hear that Hipparchos is showing little if any degradation in its solar panels, so it may be able to operate for 30 months, salvaging much of the mission. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 18 Nov 89 00:45:28 GMT From: bbn.com!ncramer@bbn.com (Nichael Cramer) Subject: Looking Down [was: Re: HST resolution] >From: cs.utexas.edu!samsung!aplcen!haven!uvaarpa!hudson!astsun9.astro.Virginia.EDU!gsh7w@tut.cis.ohio-state.edu (Greg S. Hennessy) >The resolution of HST is [roughly] 20 milliarcseconds. Let us consider... Hmmm... So this works out to a resolution of (/ (/ 20.0 1000.0) 206265) = 9.6962644e-8 radians. So, if we put the HST into low earth orbit [say, for round figures, 1000 miles = (* 1000.0 5280.0 12.0) = 6.336e7 Inches] and we pointed the satellite *down* at the earth, we would get a resolution of: (* 9.6962644e-8 6.336e7) =~ 6 Inches. Hmmm... Not bad. (But surely they wouldn't do something like that. ;) NICHAEL Let's see... if we were in orbit at only *100* miles.... ------------------------------ Date: 18 Nov 89 00:42:01 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Payload Status for 11/17/89 (Forwarded) Daily Status/KSC Payload Management and Operations 11-17-89 - STS-31R HST (at VPF) - ECS support continued for functional testing. The "no shake" portion of the functional test was successfully completed last night. Personnel are supporting the continuous VPF environmental monitoring. - STS-32R SYNCOM (at VPF) - The SYNCOM safety verification portion of launch readiness test was completed yesterday. SYNCOM cleaning and contamination inspection was completed last night. The canister was moved into the VPF airlock in preparation for Saturday's SYNCOM transfer. The remainder of the closeout activity and the configuration of the test cell is planned for today. - STS-35 ASTRO-1/BBXRT (at O&C) - IPR troubleshooting continues. Pallet panel patch was painted on panel #12. OSP mates were worked yesterday and will continue this morning. Preps for cruciform installation began after a helicoil was changed out. - STS-40 SLS-1 (at O&C) - Water servicing GSE preps and validation continue. Rack mods continue today. Yesterday during eddy current inspection two gouges were revealed and are under engineering evaluation. - STS-42 IML (at O&C) - Bio rack structural mod work is in progress. Eddy current inspection was conducted and no defects were found. ------------------------------ Date: 17 Nov 89 13:50:38 GMT From: amara!khai@uunet.uu.net (S. Khai Mong) Subject: Re: Hubble Space Telescope In article <89319.203033MRW104@PSUVM.BITNET> MRW104@PSUVM.BITNET writes: > As far as long base-line interferometry is concerned, I did some > calculations, and, going back to the continent-on-a-planet- > orbiting-A.-Centuri problem, two HST's in 3000km high orbit 180 > degrees apart would resolve North America at 4.3 light years. Going to > a higher orbit would increase the resolving power, but you have to > have some pretty impressive computer facilities to use visual LBI. It's just not a matter of computer facilities. The technology just isn't here yet. We would need *extremely* accurate clocks to synchronize the two telescopes and time individual light waves with those clocks. Or (is it *AND*?) we would need to position those two telescopes relative to each other accurate to within one wavelength of light or less. Both of which are impossible with current technology. That is why there is no visual VLBI being done now even here on the earth. I did read somewhere sometime ago about a multi-telescope facility somewhere being used for interferometry, but if I remember it, they had to site the telescope so accurately with respect to each other and the light for the telescopes was piped (really reflected) to some central location. -- Sao Khai Mong: Applied Dynamics, 3800 Stone School Road, Ann Arbor, Mi48108 (313)973-1300 (uunet|sharkey)!amara!khai khai%amara.uucp@mailgw.cc.umich.edu ------------------------------ Date: 17 Nov 89 18:01:19 GMT From: frooz!cfa250!mcdowell@husc6.harvard.edu (Jonathan McDowell) Subject: Re: Looking for US launcher family tree From article <1989Nov15.213427.7522@utzoo.uucp>, by henry@utzoo.uucp (Henry Spencer): > Titan II, ... The last Titan-Agena flew only a few months ago. > Titan III is a Titan II with two great big solid strap-ons. Minor correction: Agena flew on strapon-less Titan IIIB and Titan 34B, not on Titan II. The distinction between II and III is not the presence of the strapons but the fact that III was specifically designed for space missions. > The USAF's Thor IRBM .... > was turned into a small launcher with the addition of a modest upper > stage. You then talk about Delta, which was originally the name of a Thor upper stage; but there was a whole other family of Thor-based launchers, the Thor Agena series, which was the major launch vehicle of the 1960s. -Jonathan McDowell ------------------------------ Date: 17 Nov 89 12:38:03 GMT From: sei!firth@pt.cs.cmu.edu (Robert Firth) Subject: Re: Mars space elevator In article <8911170010.AA08134@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >Mars has one large disadvantage too: the moon Phobos orbits within the bounds >of its synchronous orbit. I don't think there's any point along Mars' equator >that Phobos doesn't eventually pass over, which would certainly affect the >performance of the space elevator! :-) This problem was discussed in Fountains >of Paradise by Arthur C. Clarke. The proposed solution was to set up a >carefully-controlled vibration in the elevator, which would cause it to >move out of the way as Phobos passed by. Um... wouldn't it be a lot simpler to move Phobos? ------------------------------ End of SPACE Digest V10 #260 *******************