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 ; Thu, 8 Feb 90 01:37:58 -0500 (EST) Message-ID: <0ZoFCiG00VcJQC1048@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 8 Feb 90 01:37:34 -0500 (EST) Subject: SPACE Digest V11 #19 SPACE Digest Volume 11 : Issue 19 Today's Topics: Re: Galileo Update - 02/06/90 (Forwarded) Imperial measurements Re: Galileo Mission Schedule Re: More Info On SSX Galileo Venus encounter (Re: Galileo Update - 02/07/90) Re: More Info On SSX Re: SR-71 BLACKBIRD Re: Galileo Update - 02/06/90 (Forwarded) Re: More Info On SSX Re: Grassroots Space "Radicals" Re: Spacecraft drives and fuel efficiency Fifth Soviet space walk done at Mir ---------------------------------------------------------------------- Date: 7 Feb 90 17:10:46 GMT From: ux1.cso.uiuc.edu!aries!wehmer@iuvax.cs.indiana.edu (James Wehmer) Subject: Re: Galileo Update - 02/06/90 (Forwarded) > NASA's Galileo spacecraft will fly by planet Venus at about >1 a.m. EST, Sat., Feb. 10, 1990, on the first leg of its gravity- >assisted flight path to planet Jupiter. Galileo will record >scientific observations for playback in October. There will be >no live or real-time science from this Venus fly-by. > Why wait eight months to download the Venus data? Is the Galileo mission schedual too busy to allow an earlier playback? Thanks, I was just wonderning. ------------------------------ Date: Wed, 7 Feb 90 15:00:26 EST From: John Roberts Disclaimer: Opinions expressed are those of the sender and do not reflect NIST policy or agreement. Subject: Imperial measurements >Subject: Re: furlongs per fortnight in space >Does anybody know of a country other than the US that still has >imperial measurments, as a standard? -------- Ha! Several people have made this mistake. The US does *not* use Imperial measurements - that's what Canada and the UK pretend not to use :-). (Yes, I realize that's nitpicking, but those who would make fun of our antique measurement system shouldn't confuse it with somebody else's.) I don't really know the name for what the US uses - probably "US Standard or "American Standard". The British Imperial measurement system is different, at least for volume measures. Moreover, the rest of the world does not use the "metric system". The standard is SI, which is short for "Systeme Internationale d'Unites" - "metric" is just a nickname nowadays. As I understand it, there are (or recently have been) two acceptable formats for SI expressions, chosen because they produce "convenient" values for many everyday measures: centimeter-gram-second (arg! hate that one - and its in all my old books!) and meter-kilogram-second (the most common one now, and probably the "true" standard). Both of these formats suffer from an idiosyncrasy left over from the beginnings of the system - measures are in terms of either a hundredth of one basic unit (length) or a thousand of another basic unit (mass). Also, common usage includes units that are not part of SI, such as the liter (the vulgar term for the cubic decimeter). In any event, the US standard *is* SI, and it has been for many years. The official US standard of length is the meter, the official standard of mass is a replica kilogram weight, and so on. The traditional measures are now defined in terms of SI units, and are used for everyday applications. This is usually only a problem if you want to mentally calculate how many cans of artichokes can be boosted into orbit using a given mass of fuel, and similar exercises. Serious calculations are generally done using SI, with the exception of certain fields of study (such as thermodynamics, which still uses *both* systems - the worst possible choice). Some aspects of space travel still use the traditional units - largely a carryover from aviation. I agree it would probably be a good idea to change this, if a way could be found to do it all at once. As several people have pointed out, the transition would be difficult. I tend to post the results of calculations in "standard" units when they are simple measures such as distance and velocity, because I think most of the people on the list are Americans, who have a more intuitive "feel" for these measures than the SI equivalents. Also, I tend to remember measures such as the astronomical unit in the traditional units. For more complex calculations, of course, it would be foolish not to convert to "metric". The US government, through NBS/NIST, has tried to persuade the public to convert to metric at several times, and has generally been resisted. Back in the early 70s (?), road signs were put up along highways giving distances in both miles and kilometers. There were complaints based on the suspicion that the mile figures would eventually be taken down, so the kilometer figures were taken down instead. In that climate of public opinion, do any of you Europeans/Canadians/etc. have any ideas on how to get the American public to switch over? (I don't think summary executions would be acceptable. :-) For hazardous, quick-response situations such as space travel, I have long felt that some new synthetic measurement system would be superior to both US standard and SI, based on the principle of KISS ("keep it simple, Stupid".) It is very seldom that an astronaut desperately needs to know the diameter of a bolt in terms of an eighteenth-century survey of the distance from the North Pole to the Equator through Paris - it's more important to quickly pick the right size wrench. Thus, bolt sizes should be "number 1", "number 2", and so on, possibly with a similar convention for bolt length. Cabin pressure might best be measured in "atmospheres" rather than psi or kPa. Other measures such as seconds and Volts could remain the same. If the astronaut really needs to know how many number 5 bolts to jettison in order to save 3 kilograms of fuel on reentry without consultation with ground control, a conversion table could be kept on board. Disclaimer: I am not an official spokesman for NIST. If anyone really wants to know, I could probably find out official government policy on measurement systems. Also, I'm much more interested in seeing more hardware in space than in what scale the gauges will be calibrated. :-) John Roberts roberts@cmr.ncsl.nist.gov ------------------------------ Date: 8 Feb 90 03:18:32 GMT From: zephyr.ens.tek.com!wrgate!mrloog!dant@beaver.cs.washington.edu (Dan Tilque) Subject: Re: Galileo Mission Schedule baalke@mars.jpl.nasa.gov (Ron Baalke) writes: > > > Galileo Schedule [abbreviated] > > 02/09/90 - Venus Flyby : > 10/29/91 - Asteroid Gaspra Flyby : > 08/28/93 - Asteroid Ida Flyby : As I understand it, one or both of the asteroid flybys may not happen. They will require extra fuel because they are slightly out of the way for Galileo. The decision to make them depends on how well the Venus flyby goes. Does anyone have more specifics? That is, when will the decision be made as to whether to make them and how much extra fuel they need for the flybys? --- Dan Tilque -- dant@mrloog.WR.TEK.COM ------------------------------ Date: 7 Feb 90 14:35:16 GMT From: eplrx7!leipold@louie.udel.edu (Walt Leipold) Subject: Re: More Info On SSX In article <5509@omepd.UUCP> larry@omews10.intel.com (Larry Smith) writes: >The first SSX will probably use RL-10 rocket engines, which >have been around a long time and are very reliable (they are >used on the Centaur upper stage). The anticipated cost of >each vehicle is around $30 million,... Do you seriously believe that you can build a reusable space vehicle for less than a quarter of the cost of a 747? If the gov't is going to be a customer, you probably won't even be able to meet the payroll of your QA dept for $30M/vehicle... >Larry Smith for Edward V. Wright -- "As long as you've lit one candle, Walt Leipold you're allowed to curse the darkness." (leipolw%esvax@dupont.com) -- -- The UUCP Mailer ------------------------------ Date: 8 Feb 90 02:38:31 GMT From: van-bc!ubc-cs!eric!dssmv2!fischer@ucbvax.Berkeley.EDU (Roger Fischer) Subject: Galileo Venus encounter (Re: Galileo Update - 02/07/90) Forgive me my ignorance but I have two questions about the Galileo Venus encounter: 1.) Is the trajectory change towards the sun (Galileo passes on the outher side of the Venus) or away from the sun (Galileo passes inside Venus). 2.) What is the heliocentric velocity of Venus and Earth compared to the current and after-encounter velocity of Galileo. Thanks for your time..... Roger ---------------------------------------------------------------------------- Roger W. Fischer fischer@mprgate.mpr.ca fischer@mprgate.UUCP ..seismo!ubc-cs!mprgate!fischer ...ihnp4!alberta!ubc-cs!mprgate!fischer ------------------------------ Date: 7 Feb 90 20:13:37 GMT From: concertina!fiddler@sun.com (Steve Hix) Subject: Re: More Info On SSX In article <21900066@m.cs.uiuc.edu>, carroll@m.cs.uiuc.edu writes: /* Written 6:14 pm Feb 5, 1990 by larry@omews10.intel.com in m.cs.uiuc.edu:sci.space */ > I recently (2/5/90) got some interesting information on > SSX from ewright@convex.com (Edward V. Wright). > [ ... ] > a useful payload of 9000 to 20,000 lb. > [ ... ] > The anticipated cost of > each vehicle is around $30 million, yielding launch costs > of about $50 per pound of payload in Low Earth Orbit. > /* End of text from m.cs.uiuc.edu:sci.space */ > Forgive my math, but I get > $30,000,000 / 20,000 lb = $1500/lb, not $50. > For a 9,000 lb payload, it's $3333/lb. Where did you get $50/lb from? It's reusable? > For a 20,000 lb payload, and $50/lb, the vehicle must cost only $1million. Mass production? :} ------------ "...Then anyone who leaves behind him a written manual, and likewise anyone who receives it, in the belief that such writing will be clear and certain, must be exceedingly simple-minded..." Plato, _Phaedrus_ ------------------------------ Date: 7 Feb 90 18:12:42 GMT From: hplabsb!dsmith@hplabs.hp.com (David Smith) Subject: Re: SR-71 BLACKBIRD In article <2112@syma.sussex.ac.uk> nickw@syma.susx.ac.uk (Nick Watkins) writes: > >>Hmmm, maybe we should hire the USAF to build copies of the F-1. > >The what? F-1 was (US) designation for the SS9 Scarp ICBM as a launcher. >Very roughly equivalent to Titan II (Martin would probably rebuild them if >you paid them enough ...:-) ) > >G-1 (US) or N1 (USSR) = old moon rocket. Was this the one you meant ? One of the most frequently asked questions in this forum is "Why can't we restart production of the Saturn V, or at least its F-1 engine?" That's the one I mean. -- David R. Smith, HP Labs dsmith@hplabs.hp.com (415) 857-7898 ------------------------------ Date: 7 Feb 90 21:02:15 GMT From: crabcake!arromdee@umd5.umd.edu (Kenneth Arromdee) Subject: Re: Galileo Update - 02/06/90 (Forwarded) Out of curiosity (and which I asked before): Is Galileo, when it reaches Earth, going to take any pictures? (Maybe they can discover life :-)) -- "Workers of the world, we're sorry!" --Soviet protestor's slogan Kenneth Arromdee (UUCP: ....!jhunix!arromdee; BITNET: arromdee@jhuvm; INTERNET: arromdee@crabcake.cs.jhu.edu) ------------------------------ Date: 8 Feb 90 00:36:25 GMT From: milton!maven!games@beaver.cs.washington.edu Subject: Re: More Info On SSX In article <21900066@m.cs.uiuc.edu>, carroll@m.cs.uiuc.edu writes: > Forgive my math, but I get > $30,000,000 / 20,000 lb = $1500/lb, not $50. > Don't forget that the vehicle is reusable. Hence you are paying only a portion of the cost of the vehicle for each flight that it makes. The real cost is fuel, and maintenance + cost of vehicle/number of flights. Or so it seems to me. ------------------------------------------------------------------------------- Trendy footer by: John Stevens-Schlick Internet?: JOHN@tranya.cpac.washington.edu 7720 35'th Ave S.W. Seattle, Wa. 98126 (206) 935 - 4384 ------------------------------------------------------------------------------- My boss dosn't know what I do. ------------------------------ Date: 7 Feb 90 19:32:16 GMT From: thorin!cassatt!leech@mcnc.org (Jonathan Leech) Subject: Re: Grassroots Space "Radicals" In article <1990Feb7.005913.3290@agate.berkeley.edu> gwh@ocf.Berkeley.EDU (George William Herbert) writes: >Can we take this into email and off the net? >NOW? Heavens, whatever for? I find it refreshing that someone with direct knowledge of the events Bowery complains about is responding. -- Jon Leech (leech@cs.unc.edu) __@/ "A compact set can be controlled by a finite police force no matter how dumb." H. Weyl ca. 1938 ------------------------------ Date: 7 Feb 90 17:25:19 GMT From: zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!aplvax.jhuapl.edu!jwm@tut.cis.ohio-state.edu (Jim Meritt) Subject: Re: Spacecraft drives and fuel efficiency Voyager is getting a pretty good MPG. :-) That that is is that that is. That that is not is that that is not. That that is is not that that is not. That that is not is not that that is. And that includes these opinions, which are solely mine! jwm@aplvax.jhuapl.edu - or - jwm@aplvax.uucp - or - meritt%aplvm.BITNET ------------------------------ Date: Wed, 7 Feb 90 09:59:33 EST From: Glenn Chapman To: biro%hydra.enet.dec.com@decwrl.dec.com, isg@bfmny0.uu.net, klaes%wrksys.dec@decwrl.dec.com, lepage%vostok.dec.com@decwrl.dec.com, space-editors-new@andrew.cmu.edu, yaron@astro.as.utexas.edu Subject: Fifth Soviet space walk done at Mir On Feb. 5th at the Soviet's Mir Space Station cosmonauts Alexander Viktorenko and Alexander Serebrov made their fifth space walk this year, and tested their Manned Maneuvering Unite (MMU), called a "space bicycle" or Icarus. Again exiting the Kvant 2 module airlock station commander Viktorenko flew the space bicycle in excess of 40 meters (131 ft.) from Mir, and measured radiation levels at a number of points and distances from the station. Serebrov, who flew the MMU last time, stood by the safety rope and check the behavior of Icarus. The statements said that similar space bicycles will be used on their new Mir II station (slated for mid 1990's) and with the Buran space shuttle. (Radio Moscow Feb. 4-6) The replacement crew for Mir will be launched on Soyuz TM-9 on Feb. 11, and the current crew will come down on Feb. 24th. The crew for this 6 month mission will be Anatoly Solovyov (Soyuz TM-5/Mir Jun. '88 for 9 days) and Alexander Balandin, a new cosmonaut. It seems that the following mission, Soyuz TM-10, scheduled for July '90, will bring up a shuttle pilot for zero G experience. Currently the crew suggest is Vitally Serastyanov, Viktor Afanasyev, and Burna pilot trainee Rimantas Stankyavichus. Serastyanov is an old time cosmonaut, selected in 1967, flew Soyuz 9 in June 1970 for 17 days, Soyuz 18/Salyut 4 in May 1975 for 63 days and was a manager in the Soviet Lunar Landing training program. The flight of a Japanese journalist to Mir has been moved up from 1991 to the fall of this year. Toehiro Akiyama and Ryoko Kikuchi, the two correspondents from Japan's TSB network, have been in Russia training since Oct. '89. (TASS announcement Jan. 18, Spaceflight Jan '90, Phil Clark, "Soviet Manned Space Program") The Soviets have a second space station still in orbit, the old Salyut 7 with the large Cosmos 1686 module attached to it. Launched in April 1982, it was last visited in May 1986 when the Soyuz T-15 crew which first visited Mir transferred from Mir to Salyut 7 for almost two months, then back again. Many people have been speculating that the Russians would try to bring Saylut 7 down in their space shuttle. However, Vladimir Dzhanibekov, head of cosmonaut technical training, recently said this was just a western concept. Dzhanibekov is the cosmonaut who rescued Salyut 7 in June 1985 when it suffered a major power system failure. Salyut 7 is out of fuel, drifting in a gravity gradient mode with the main station section towards the earth, hence a high air resistance mode. It is also precessing, that is sinning slowly like a gyroscope that has been bumped, so that the base end stays nearly stationary while the tip of the Cosmos 1686 module forms a circle about it. Their main worry is that the combined structure weights nearly 40 tonnes, and probably parts would survive reentry. They are currently considering sending either a special Progress tanker which would use its engines to create a reentry over an ocean, or perhaps mount a manned Soyuz mission to do the same. Manned missions are considered because of the unusual motion of the station. It appears that the human race is back to having a manned space station for these plans extend for another two years. Glenn Chapman MIT Lincoln Lab ------------------------------ End of SPACE Digest V11 #19 *******************