Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from corsica.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Sun, 30 Jul 89 00:21:51 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 30 Jul 89 00:21:42 -0400 (EDT) Subject: SPACE Digest V9 #567 SPACE Digest Volume 9 : Issue 567 Today's Topics: Re: Impossible Space Goals Re: Significance of July 20th Re: Lagrangian Points Re: Apollo 8, 9, and 10 Re: Kuiper Airborne Observatory PHONE TREE ALERT Re: Lagrangian Points Re: Questions about Apollo 11 Re: Apollo 11 program alarms Re: Apollo 8, 9, and 10 Re: Impossible Space Goals ---------------------------------------------------------------------- Date: 19 Jul 89 13:46:51 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: Impossible Space Goals In article <1699@infinet.UUCP> rhorn@infinet.UUCP (Rob Horn) writes: >In article <4304@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes: >> ... You will see the great unknowns at the time: >>Was the surface of the moon hard or miles of dust for a lander to sink? > >There were even two series of Lunar probes launched to specifically >answer this and related questions. It was nice back in the days when >you could have short turnaround simple missions. Specific focused >goals and specific focused schedules are so much easier to work with >than ongoing generic projects. Whoa. Assuming Zond doesn't count, there were two programs where unmanned spacecraft touched the lunar surface: Ranger and Surveyor. Ranger was a hard ballistic impact probe which relayed TV pictures on the way down. The final pictures were taken a few thousand feet above the surface; nobody really knew what happened when a Ranger hit. Dust or basalt would have extinguished the craft with equal efficiency. The first real answers about Lunar composition (remember to forget Zond) came from Surveyor. It did everything you could have asked -- it was a terrific program, my all time favorite until Viking. (After Viking, it's a tie.) But it was NOT a short turnaround mission. In fact it was one of the few vestiges of the PRE-Apollo, pre-Kennedy-challenge notion of the US space program. Surveyor had been on the books for about six years. With the crash Kennedy program, the three manned spacecraft became top priority and Ike's stuff languished at JPL, underfunded and behind schedule. In 1963 or 64 it was realized that Surveyor could provide key answers needed to build an LM. (I don't think anyone at NASA took Gold's theory of mile deep dust oceans very seriously, but it still makes a difference whether you're landing on bricks or sand.) So Surveyor got a funding and management push along with the Lunar Orbiter cameras (now THERE was a simple mission). For me, Surveyor was the real first glimpse of the Moon as another world. When Apollo astronauts followed in its footsteps (literally with 12), we saw an awesome sight -- one which had run in LIFE three years before. -- "My God, Thiokol, when do you \\ Tom Neff want me to launch -- next April?" \\ uunet!bfmny0!tneff ------------------------------ Date: 19 Jul 89 19:54:45 GMT From: elroy.jpl.nasa.gov!jpl-devvax!leem@decwrl.dec.com (Lee Mellinger) Subject: Re: Significance of July 20th In article <8907181750.AA09311@ti.com> pyron@lvvax1.csc.ti.com (Who remembers 8USER.PAR?) writes: I'd like to remind everyone that July 20th is also the 13th anniversary of the Viking I soft landing on Mars. Lee |Lee F. Mellinger Caltech/Jet Propulsion Laboratory - NASA |4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516 FTS 977-0516 |{ames!cit-vax,}!elroy!jpl-devvax!leem leem@jpl-devvax.JPL.NASA.GOV ------------------------------ Date: 19 Jul 89 04:08:51 GMT From: crdgw1!ge-dab!sunny!harrison@uunet.uu.net (Gregory Harrison) Subject: Re: Lagrangian Points In article <15070@ut-emx.UUCP> sudhama@walt.cc.utexas.edu (Chandrasekhara Sudhama) writes: >Hello, this is my first posting. Would someone please explain >(either on this network or in private email) the stability of the >equilibrium points in the Earth - Moon system? From my L5 days, the straight line points, on the Earth-Moon line are 2/3 stablewhich means that the satellites placed at these straight-line libration points, L1, L2, and L3 can move in a plane that is perpendicular to the line joining theEarth and the Moon, and the libration phenonenon at these 2/3 stable points actsso as to return the satellite to the libration point. But if the satellite moves towards the Earth or Moon, the satellite will continue approaching the Earth or Moon. Thus the L1, L2, and L3 points are 2/3 stable, i.e. they return to the libration point from 2 of the 3 possible dimensions it can traverse away from the libration point. On the othe r hand, the L4 and L5 points are stable in all 3 dimensions. The satellite can move anywhere about the point (within some kidneyshaped bounds) and still experience forces that draw it back into the libration point. The L5 point, namesake of the pioneering space settler society, is trailing the Earth in the Earth-Moon system cyclical progression (I believe) as the Earth andMoon rotate about their combined center of rotation. I think that was the case,and I believe the L5 Society decided on that location for settlement due to enhanced safety in case of emergency. The Earth would be moving away from the Settlement and pose less of a danger should the satellite orbit be perturbed. The 2/3 stable points are useful despite the instability in the 3rd dimension. There was, and may still be, a satellite placed at the libration point between the Earth and the Sun, and set into an orbit about the line between the Earth and the Sun such that when viewed from the Earth (with appropriate equipment, not eyes, of course) the satellite would circumscribe the borders of the Sun. NASA had redirected this satellite into that orbit after it had completed some other mission. Perhaps it was called Solar Max, I can't recall. Perhaps someone else out there would know. Maybe the L5er ==> NSS member who originally passed the news to me may be on the net and would know. The mathematical formulations of the other postings on this subject are very interesing. It would be interesting to know what all those numbers mean. For instance the 24.999~, and the 27* ... etc. There must be a good reference? To The Stars, Greg Harrison NSS member ------------------------------ Date: 19 Jul 89 15:51:09 GMT From: asuvax!enuxha!kluksdah@handies.ucar.edu (Norman C. Kluksdahl) Subject: Re: Apollo 8, 9, and 10 In article <17231@bellcore.bellcore.com>, ddavey@grits.ctt.bellcore.com (Doug Davey) writes: > Does anybody remember whether the ascent or descent engine was used > during Apollo 10's return from low orbit to rendezvous with the CSM? > Either option seems difficult. On the one hand, I would not expect > the descent engine to be restartable. On the other, firing the > ascent engine and getting the ascent stage cleanly separated from the > descent stage would be tricky since the descent stage was deigned to > be firmly on the lunar surface during this operation. > The LM used nitrogen tetraoxide and hydrazine (was it UDMH or some other chemical variant???) as oxidizer and propellant. These are hypergolic propellants, which means that you don't need an igniter--the chemicals hate each other so much that they ignite on contact (paraphrased from "Chariots for Apollo"). So, if you can control the fuel and oxidizer valves (simple, since the engines had to have thrust control, so valves were there), you can re-start the engine repeatedly, until you run out of fuel. My memory indicates that the descent stage was cut free, and the ascent stage was used for the rendezvouz. Again, the book "Chariots for Apollo" gives some very human-oriented insight into this process. Some of the engineers at Grumman who were responsible for the separation never did watch or listen to a take-off from the moon. There were many pyrotechnic charges for the separation, each of which powered a guilliotine to sever electrical, water, air, etc, lines between the ascent and descent stages. Failure of one of the guilliotines would have been catastrophic. If you haven't read this book, find it. It is very good, IMHO. ********************************************************************** Norman Kluksdahl Arizona State University ..ncar!noao!asuvax!enuxha!kluksdah alternate: kluksdah@enuxc1.eas.asu.edu standard disclaimer implied ------------------------------ Date: 19 Jul 89 20:02:15 GMT From: elroy.jpl.nasa.gov!jpl-devvax!leem@decwrl.dec.com (Lee Mellinger) Subject: Re: Kuiper Airborne Observatory In article <150@cfa.HARVARD.EDU> willner@cfa.HARVARD.EDU (Steve Willner) writes: :> Now take the Kuiper observatory. Why is NASA in charge? Ya got me, :> buddy. (I know NSF and others help adminstrate.) : :Just a tiny correction. The KAO is entirely operated by NASA - no NSF :or other agency involvement whatever. The next-generation airborne :observatory (SOFIA - Stratospheric Observatory For Infrared Astronomy) :will be a joint project of NASA and the West German space agency. :(BMFT, I think, though darned if I know what the initials stand for.) : :Steve Willner Phone 617-495-7123 Bitnet: willner@cfa BMDT = Bundes Ministerium fuer Forshung und Technologie = Federal Ministry for Research and Technology. (spelling is probably not quite right) Lee "I'm the NRA" |Lee F. Mellinger Caltech/Jet Propulsion Laboratory - NASA |4800 Oak Grove Drive, Pasadena, CA 91109 818/393-0516 FTS 977-0516 |{ames!cit-vax,}!elroy!jpl-devvax!leem leem@jpl-devvax.JPL.NASA.GOV BMFT = ------------------------------ Date: 19 Jul 89 14:22:39 GMT From: agate!web%garnet.berkeley.edu@ucbvax.Berkeley.EDU (William Baxter) Subject: PHONE TREE ALERT Call Congressman Robert Roe (D-NJ) at 202/225-5751. Ask him, as chairman of the House Science, Space and Technology Committee, to hold hearings on HR2674, the Space Transportation Services Purchase Act of 1989, as soon as possible. William Baxter ARPA: web@{garnet,brahms,math}.Berkeley.EDU UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web CALL YOUR CONGRESSMAN NOW AND SCREAM AT HIM UNTIL HE EQUATES "NASA" WITH "SPACE PROGRAM" ------------------------------ Date: 19 Jul 89 12:57:13 GMT From: b.gp.cs.cmu.edu!Ralf.Brown%B.GP.CS.CMU.EDU@pt.cs.cmu.edu Subject: Re: Lagrangian Points In article <2100@ge-dab.GE.COM>, harrison@sunny.DAB.GE.COM (Gregory Harrison) wrote: }The 2/3 stable points are useful despite the instability in the 3rd }dimension. There was, and may still be, a satellite placed at the libration point between } the Earth and the Sun, and set into an orbit about the line between the Earth and } the Sun such that when viewed from the Earth (with appropriate equipment, }not eyes, of course) the satellite would circumscribe the borders of the Sun. NASA } had redirected this satellite into that orbit after it had completed some } other mission. Perhaps it was called }Solar Max, I can't recall. Perhaps someone else out there would know. Maybe }the L5er ==> NSS member who originally passed the news to me may be on the net }and would know. The one satellite I can recall in such an orbit was reused as the International Comet Explorer or some such name--NASA spent 18 months maneuvering it through a complex trajectory around the earth-moon system using multiple gravity boosts to get it into solar orbit and fly by a comet, all on station-keeping fuel! It even managed to beat out all the Halley fly-bys by a few months, going to a different comet. Too bad the original mission didn't require cameras.... -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/46 FAX: available on request Disclaimer? I claimed something? PROGRAM n. A magic spell cast over a computer allowing it to turn one's input into error messages. tr.v. To engage in a pastime similar to banging one's head against a wall, but with fewer opportunies for reward. -- from a flyer advertising for _Inside_Turbo_Pascal_ ------------------------------ Date: 19 Jul 89 20:46:12 GMT From: ames.arc.nasa.gov!mike@ames.arc.nasa.gov (Mike Smithwick) Subject: Re: Questions about Apollo 11 In article <1989Jul15.214136.8236@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: < In that CBS special it appeared that Armstrong made that decision. He > said something to the effect, "Hang tight, we're going" and just kep > going when the program alarm came up. Among recently published books, both Aldrin's MEN FROM EARTH and Harry Hurt III's FOR ALL MANKIND describe the events surrounding the 1202 and 1201 alarms. Both books claim that Bales, as GUIDO, made the decision to ignore the alarms. (I don't believe that Collins deals with this topic in either of his books, but I could be wrong about that.) -- Charlie Richter MCC Austin, Texas uucp: richter@milano.uucp arpa: richter@mcc.com "The panic ... was not due to anything fundamentally weak in either business or finance. It was confined to the market itself." - WSJ, Oct. 31, 1929 ------------------------------ Date: 19 Jul 89 17:24:02 GMT From: ingr!boley@uunet.uu.net (Kirk Boley) Subject: Re: Apollo 8, 9, and 10 In article <1989Jul19.005449.3163@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > There was some discussion about whether Apollo 10 was really needed; why > get to within 10 miles of the lunar surface and then go home? But a lot > of people felt that an all-up test, including a real lunar-orbit rendezvous, > was a good idea before landing. What finally settled the matter was that > Apollo 10's LM was overweight and could not have flown a complete landing > mission. > -- > $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology > (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu I always wondered about that, after reading about the descent. (I was too young to remember much about the space program, even though my dad was working on the Saturn V Instrument Unit for IBM.) I remember thinking, "Hey if it was me, I'd made up some sort of excuse for going ahead and landing!" I mean really, it's like Christopher Columbus coming to within 30 feet of the American shoreline and saying, "Nah, this is too dangerous, let's go back." It's nice to know the real reason after all these years. Thanks, Henry. -- ******************************************************************************* Standard disclaimer. | Kirk Boley, Intergraph Huntsville, UAH Witty .sig message. | 61 hours to go and counting... ...!uucp!ingr!boley ******************************************************************************* ------------------------------ Date: 18 Jul 89 20:29:06 GMT From: gem.mps.ohio-state.edu!ginosko!infinet!rhorn@tut.cis.ohio-state.edu (Rob Horn) Subject: Re: Impossible Space Goals In article <4304@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes: >>In article <11246@cit-vax.Caltech.Edu>, jerbil@cit-vax.Caltech.Edu (Stainless Steel Gerbil [Joe Beckenbach]) writes: >>}My two cents: those in JFK's world saw the Moon as "impossibly far", > >Ain't hindsight wonderful? > >To understand why they used that adjective, you must get library books >dated prior to 1961. You will see the great unknowns at the time: >Was the surface of the moon hard or miles of dust for a lander to sink? There were even two series of Lunar probes launched to specifically answer this and related questions. It was nice back in the days when you could have short turnaround simple missions. Specific focused goals and specific focused schedules are so much easier to work with than ongoing generic projects. I even recall one wonderful day when discussing some problem (I forget what) someone seriously suggested designing and launching a simple satellite to discover the answer. Today you must politic for years to create a new satellite. I hope that some of the quick response and creativity returns with some of the projects like cheapsat. -- Rob Horn UUCP: ...harvard!adelie!infinet!rhorn ...ulowell!infinet!rhorn, ..decvax!infinet!rhorn Snail: Infinet, 40 High St., North Andover, MA ------------------------------ End of SPACE Digest V9 #567 *******************