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 ; Mon, 31 Dec 1990 03:17:28 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 31 Dec 1990 03:16:59 -0500 (EST) Subject: SPACE Digest V12 #703 SPACE Digest Volume 12 : Issue 703 Today's Topics: Galileo article Re: Who killed Nuclear Rockets? (was Re: The Next Ten Years In Space) Re: Air pressure questions (A human being in vacume) Re: Interstellar travel Re: NASA's Manned/Unmanned Track Record (Re: Another Russian first) Magellan Update - 12/14/90 Re: Another Russian first pressure-altitude relation Galileo Update #3 - 12/14/90 COBE spinning not tumbling Re: Light years and such Re: Recent DoD Space System Cost Data ... Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 14 Dec 90 22:01:51 GMT From: van-bc!ubc-cs!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucbvax.Berkeley.EDU (Ron Baalke) Subject: Galileo article Washington Times -- 12/14/90 "Galileo Pictures Far Side of Moon" "Pictures by the Galileo spacecraft as it boomeranged past Earth on its way to Jupiter show icy Antarctica and a giant meteorite impact crater on the far side of the moon." The story reports that the last photos of the far side of the moon were made by the Apollo astronauts two decades ago and quotes Galileo project scientist Torrence Johnson as saying "this is the first time we've had a chance to use a spacecraft designed to explore another planet to come back and look at our own Earth and moon as if we were alien observers." The Times continues quoting Johnson, "In the process, we're learning some new scientific things about our own world and its companion, but perhaps more importantly, it's providing us a different perspective on our home planet as a fragile world." The story says that this past Saturday, Galileo swooped 597 miles above the southwest Atlantic Ocean, using Earth's gravity as a slingshot to help expand the spacecraft's orbit around the sun so it can reach Jupiter in 1995. The paper says that Galileo used Venus for the same purpose this previous February and will fly by Earth again in December 1992. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 15 Dec 90 19:02:13 GMT From: usc!wuarchive!rex!rouge!dlbres10@apple.com (Fraering Philip) Subject: Re: Who killed Nuclear Rockets? (was Re: The Next Ten Years In Space) In article <1990Dec10.212252.8895@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >Dumbo. See Kingsbury's "Notes on Nuclear Rockets". Basically, Dumbo >was a somewhat more radical concept than NERVA, and lost out to it when >funding got tight. Where can I find this? Is it an article? A book? Phil F. dlbres10@pc.usl.edu ------------------------------ Date: 14 Dec 90 18:44:50 GMT From: hpda!hpcupt1!hpindwa!kinkley@ucbvax.Berkeley.EDU (David Kinkley) Subject: Re: Air pressure questions (A human being in vacume) On a related note. Can anybody give me the relationship between altitude and air pressure. I'm starting to do a lot of alpine climbing and have been trying to figure this out for a while. An equation would be best but I'll settle for some kind of altitude vs. pressure table if the numbers are accurate (not that I don't treat everything I read in this group as gospel ;-) Dave Kinkley kinkley@hpindwa.HP.COM ------------------------------ Date: 15 Dec 90 14:52:30 GMT From: csus.edu!wuarchive!zaphod.mps.ohio-state.edu!samsung!news.cs.indiana.edu!noose.ecn.purdue.edu!en.ecn.purdue.edu!irvine@ucdavis.ucdavis.edu (/dev/null) Subject: Re: Interstellar travel In article <9012131704.AA08545@hermes.intel.com>, thamilton@ch3.intel.com (Tony Hamilton, WF1-81, x48142) writes: > Could anyone tell me what the latest designs are for interstellar starships? > I had done some real 'light' reading on the subject, and could glean that the > two most feasible designs were the Air Force's Orion starship (was that given ^^^^^^^^^^^^^^ I believe the Orion was discarded due to technical difficulties - it relied upon the continuous detonation of atomic bombs in a reaction chamber to supply the thrust - not much even on the forefront in the way of materials that can withstand a direct nuclear explosion with no appreciable damage. > up?), and the Bussard(sp?) Ramjet. Most of what I've heard of these two The Bussard Ramjet I feel may be the most 'practical' if one can find a way of a) getting it to 'Ramjet Speed.' and if there is enough hydrogen per cubic meter that makes the fusion thrust possible. For the moment, quick efficient interplanetary travel will probably offer good solutions. Lightsail, Ion-drive (1970's developed by NASA), etc. Also, I think the main problem with long term acceleration and fuel are the biggest technical challenges that Orion and Bussard tried to circumvent! Brent Irvine -- Brent L. Irvine Malt Beverage Analyst +-----------------------------------------------------------------------+ ------------------------------ Date: 12 Dec 90 04:56:15 GMT From: igloo!ddsw1!corpane!disk!joefish@gargoyle.uchicago.edu (joefish) Subject: Re: NASA's Manned/Unmanned Track Record (Re: Another Russian first) In article <1990Dec7.162815.2035@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: > >Skylab 1 got delivered to the Australians in pieces. Skylab 2 is in the >NASM. (Yes, there was a second one.) And according to AW, Dec. 10, Salyut 7 space station will reenter and burn sometime around Jan or Feb, 1991. The orbit is inclined at 51.6 degrees, so most everyone is at risk-:-) Salyut was launched in early 1982. Joe Fischer joefish@disk.UUCP ------------------------------ Date: 14 Dec 90 17:58:04 GMT From: snorkelwacker.mit.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@bloom-beacon.mit.edu (Ron Baalke) Subject: Magellan Update - 12/14/90 MAGELLAN STATUS REPORT December 14, 1990 The Magellan spacecraft is in good health and performing nominally. All seven STARCALS (star calibrations) since yesterday were successful with small attitude updates. Later today the M0349 mapping sequence will be sent up, the first of six occulted mapping sequences. This sequence will shorten the mapping pass by 6.5 minutes in order to accommodate 46 minutes of earth occultation during the playback. Spacecraft engineers met yesterday to discuss the probable causes of the tape recorder A deterioration. There is no concern at this time about the continued use of tape recorder B. The single tape recorder strategy remains scheduled to start on December 22. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 14 Dec 90 14:48:23 GMT From: mcsun!hp4nl!dutrun!dutlru1!dutlru2!wi@uunet.uu.net (Edwin Wisse) Subject: Re: Another Russian first >>In article techno@lime.in-berlin.de (Frank G. >>Dahncke) writes: >>> Now the USSR even has had the first paying passenger in a spacecraft. >>> Actually, I would have expected this feat to be performed by the US. > In dcorbett@phobos.socs.uts.edu.au (Dan Corbett) writes: >Does SpaceLab count here? I believe SpaceLab 1 was sponsored by the ESA and >had a German scientist along. No it doesn't count. Spacelab was not sponsored by ESA, it was developed and built by ESA. It was a cooperation with NASA, the deal was that ESA made Spacelab and got a launch with for it, after the flight Spacelab was NASA's. Pretty good deal for NASA... -- ___ __ | | Edwin Wisse TU Delft wi@dutlru2.tudelft.nl ___ | | | F. of Aeospace En. vlrustc@hdetud1.tudelft.nl ------------------------------ Date: 16 Dec 90 06:10:40 GMT From: bloom-picayune.mit.edu!news@bloom-beacon.mit.edu (Matthew T Velazquez) Subject: pressure-altitude relation In article 26774 of sci.space Dave Kinkley writes: ^could somebody give me a pressure-altitude relation... Depends on the atmospheric model you use. For the troposphere (valid up to circa 20 km): P(sea level)/P(z) = [1-L/T(sea level)]^^gamma/(1-gamma) This reads: P of sea level over P of altitude z equals (1 minus L over T of sea level) to the power of (gamma over 1 minus gamma). Where L = 6.5 kelvins/km altitude and gamma = 1.41 for air. For the stratosphere ( valid from c. 20 km - 50 km): P(z) = P(sea level) exp(-gz/RT) In SI units, Pressure is in Pascals and T is in kelvins. Pressure at sea level is 1.013 x 10^^5 pascals. I'm too lazy to look up unit conversions for the rest of the stuff, so I guess you're out of luck in that regard. T Velazquez MIT Aero/Astro brndlfly@athena.mit.edu ------------------------------ Date: 14 Dec 90 23:39:50 GMT From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@apple.com (Ron Baalke) Subject: Galileo Update #3 - 12/14/90 GALILEO MISSION STATUS December 14, 1990 The Galileo spacecraft is 2.8 million miles from Earth, receding at about half a million miles per day. At 89.3 million miles, it is closer to the Sun than the Earth is, and will continue approaching the Sun on this orbit until January 11, when its present solar orbit will carry it back outward, this time toward the Asteroid Belt. Present orbital speed is almost 80,300 mph relative to the Sun. Spacecraft health and mission performance continue to be excellent. A sun-pointing maneuver was successfully completed yesterday. Today the Deep Space Network is sending the first part of the first post-Earth cruise sequence to the spacecraft. The current sequence, which includes all the Earth-Moon scientific observations, runs until Monday morning. The new sequence will control spacecraft activities until mid-February 1991. Scientific observations of the Earth-Moon system will be winding up tomorrow, and the scientists are busy analyzing and interpreting the results. They will give a first look at these results at a press conference at 10 a.m. (PST) Wednesday, December 19, 1990, at JPL and via the NASA SELECT satellite TV link. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 15 Dec 90 22:10:27 GMT From: isis!scicom!wats@uunet.uu.net (Bruce Watson) Subject: COBE spinning not tumbling Bruce, As one on the COBE project, let me assure you that the radiatively cooled instruments on COBE are still very much alive and taking data, although the cryogenically cooled instruments were turned off after helium depletion in late September. What you observed was sunlight reflected off the three symmetrically placed solar panels; since COBE spins about its symmetry axis at 0.8 RPM, the reflection from the panels will vary with a period of about 25 s. The period just before winter solstice is the best time of year for naked-eye observations of COBE. -Phil Keegstra- XRPBK@AMARNA.GSFC.NASA.GOV (STX - COBE project at NASA Goddard) AMARNA::XRPBK Thanks for that info, Phil. I'm posting it since I got a number of responses to my original inquiry. For those of you interested in observing COBE, it is passing over Denver at roughly 0:25 UT (23:25 MST) going south to north. It's period is 102.7 minutes. It remains sunlit throughout the year as a result of its sun-synchronous orbit. During the rest of the year twilight occurs too late in the evening for us to see it. Observe now. I'll lose it in sunlight before the end of the year. ------------------------------ Date: 12 Dec 90 04:03:12 GMT From: usc!zaphod.mps.ohio-state.edu!rpi!uupsi!cci632!ritcsh!ultb!ritvax.isc.rit.edu!swd0170@ucsd.edu (DAVIS, SW) Subject: Re: Light years and such In article , C491153@UMCVMB.MISSOURI.EDU ("John Schultz") writes... >Whenever I hear about a new telescope (such as the HST, etc.) I also hear >that the new telescope will be able to see even farther into the past. Now, >I have no trouble with the idea of light speed, light years, etc., but how >can one telescope see back farther than another? Is it due to focusing power, >or somethin ssimilar? > >:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: >: John Schultz :Disclaimer : I *pay* for this - : >: University of Missouri - Columbia :do you think the bureaucracy : >: Bitnet : C491153@UMCVMB.Bitnet :cares what I say??? : >: Internet : C491153@UMCVMB.Missouri.EDU (128.206.1.1) : >:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: >: Don't dream it, be it... - Frank N. Furter, "RHPS" : >:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: As I read it in many articles about Hubble,the reasont that Hubble can see "farther" is not because of its size nor focusing power. Compared to the size of many ground space telescopes,Hubble is only a toy. What Hubble does have as an advantage is that it escapes the atmosphere and its effects on light. Air currents disrupt the light from the stars and galaxies (i.e. the "twinkle"). Supposedly,HST would be able to see twice as far as any ground based optical telescope. I am not sure how the defective mirror aboard Hubble will effect this though... Scott ------------------------------ Date: 14 Dec 90 04:51:59 GMT From: swrinde!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Wales.Larrison@ucsd.edu (Wales Larrison) Subject: Re: Recent DoD Space System Cost Data ... Thanks for the reference Glenn! I had my suspicions the Centaur costs had been cranked into the Titan program cost - although I don't know why they would do so, since the upper stage costs for the IUS aren't... >3) IUS was originally procured not for use on Titan IV, but on the >shuttle(?). Hmm... I think you're right, since the IUS is the poor-man's "Space Tug" which was originally included in the studies done in the early 1970's. However, if I remember correctly, the first IUS launch was on a Titan. (type Titan 34?). >4) The cost of the Centaur subcontract and the number of Centaurs >being built is given in the latest Aviation Leak (but you'll have >to look it up, I don't remember). Found it, 3 Dec 90, Page 17. "The new Centaur when mated with the AirForce/Martin Marietta Titan 4 is capable of placing 10,000 lb payloads into geosynchronous orbit. ... General Dynamics will supply 15 of the upgraded Centaur stages under a $1.3 B subcontract to Marting Marieeta covering development production and launch support operations." Now, to go back and adjust my original calculations.... Dollar values are in millions, and are the estimated costs to completion of the program. I calculated the current unit average to get an average unit cost in current dollars. Current year $ is FY 1991$ (Oct 1990) SAR CURRENT ESTIMATE (modified) Current System BASE BASE CURRENT SYSTEM Unit YEAR YEAR $ YEAR $ QTY Average --------------------------------------------------------------- TITAN IV(incl Centaur)85 12,620.3 17,009.1 75.0 226.8 (Centaur 90 1,300.0 1,365.0 15.0 91.0) TITAN IV(w/o Centaur) 85 -------- 15,644.1 75.0 208.6 Note: the revised current average cost per unit of the Titan IV is about $208.6 Million with 75 vehicles to be produced, and at about 40,000 lbs into 100 nmi 28.5 deg orbits, this is still about $5215/lb. This number is closer to what I've seen from other sources. I've assumed the Centaur costs to be FY 1990 $ to be conservative. To a typical shuttle orbit Titan-4 capability reduces to about 39,250 lbs, or to $5315/lb. To Space Station orbit of about 250 nmi, its about to about 38,000 lbs, for about $5489/lb. To GEO, using a Centaur with itse 10,000 lb capability, the Titan- 4/Centaur cost is about $(208.6+91.0)=$299.6M, for about $30,000/lb. (Note: I'm posting an equivalent set of estimates for the Delta II) Thanks again, Glenn. ------------------------------------------------------------------- Wales Larrison Space Technology Investor -- Wales Larrison Internet: Wales.Larrison@ofa123.fidonet.org Compuserve: >internet:Wales.Larrison@ofa123.fidonet.org -------------------------------------------------------------------------- ------------------------------ End of SPACE Digest V12 #703 *******************