Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Wed, 27 Mar 91 01:52:15 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Wed, 27 Mar 91 01:52:11 -0500 (EST) Subject: SPACE Digest V13 #303 SPACE Digest Volume 13 : Issue 303 Today's Topics: Re: JPL spacecraft railguns,superguns Re: railguns and electro-magnetic launchers Pioneer 11 Update - 03/22/91 Free CRAY time to SISAL users Re: Space Station 'Fred' Restructuring Re: "Follies" Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 20 Mar 91 08:32:57 GMT From: elroy.jpl.nasa.gov!jato!mars!baalke@decwrl.dec.com (Ron Baalke) Subject: Re: JPL spacecraft >In article <1991Mar16.012153.15047@jato.jpl.nasa.gov> baalke@mars.UUCP (Ron Baalke) writes: >>Well, be honest: "as usual", not "as always". JPL has had failures. > ^^^^^^^^^^^^^^^^^^^^^ >This is true, but the last one was in 1964 with Ranger 6. > I've made a mistake here. It turns out that Mariner 8 in 1971 had a launch failure, but since that involved the launch vehicle, and not the spacecraft itself, you would have to go back to Surveyor 4 in 1967 to find a JPL mission that failed to meet its primary mission objectives due to a spacecraft malfunction. JPL is the only one to send spacecraft to all of the planets except Pluto. It is true JPL has had mission failures, particularly in the early years of the space program, but this have been far outweighed by the successes achieved by the JPL spacecraft. The man who makes no mistakes is the man who has not done anything. For reference, below is a list of the JPL spacecraft and their missions, and are listed in the order of their launch date. 1958 Explorer 1 - Earth orbiter, first successful U.S. spacecraft (in response to Sputnik) 1961 Ranger 1 - Moon flyby, failed to leave Earth orbit Ranger 2 - Moon flyby, failed to leave Earth orbit 1962 Ranger 3 - Moon lander, launch error caused spacecraft to miss the Moon Ranger 4 - Moon lander, spacecraft failure, crashed on the Moon Mariner 1 - Venus flyby, launch failure Mariner 2 - Venus flyby, first spacecraft to successfully flyby another planet Ranger 5 - Moon lander, spacecraft failure, missed Moon 1964 Ranger 6 - Moon impact, cameras failed, impacted on Moon Ranger 7 - Moon impact, first closeup pictures of Moon's surface Mariner 3 - Mars flyby, launch failure & spacecraft went into heliocentric orbit Mariner 4 - Mars flyby, first spacecraft to flyby Mars 1965 Ranger 8 - Moon impact, successfully returned photographs Ranger 9 - Moon impact, successfully returned photographs 1966 Surveyor 1 - Moon lander, first spacecraft to soft land on the Moon Surveyor 2 - Moon lander, crashed on the Moon 1967 Surveyor 3 - Moon lander, successful Moon landing Surveyor 4 - Moon lander, lost contact with spacecraft, possible landing Mariner 5 - Venus flyby, successful Venus flyby Surveyor 5 - Moon lander, successful Moon landing Surveyor 6 - Moon lander, successful Moon landing 1968 Surveyor 7 - Moon lander, successful Moon landing 1969 Mariner 6 - Mars flyby, successful Mars flyby Mariner 7 - Mars flyby, successful Mars flyby 1971 Mariner 8 - Mars flyby, launch failure Mariner 9 - Mars orbiter, first spacecraft to orbit Mars 1973 Mariner 10 - Mercury/Venus flyby, successful Venus flyby and first spacecraft to flyby Mercury 1975 Viking 1 - Mars lander/orbiter, first spacecraft to successfully land on Mars Viking 2 - Mars lander/orbiter, successful Mars landing 1977 Voyager 1 - Jupiter/Saturn flyby, successful flybys of Jupiter and Saturn, mission still active Voyager 2 - Jupiter/Saturn/Uranus/Neptune flyby, all flybys successful, first spacecraft to flyby Uranus and Neptune, mission still active 1978 Seasat - Earth radar mapper, partially successful, mysteriously lost contact with spacecraft 1983 IRAS - Infrared Earth orbiter, successful 1989 Magellan - Venus orbiter, successful mapping of Venus, mission still active Galileo - Jupiter orbiter/Venus-Earth flyby, successful flybys of Venus and Earth, mission still active 1990 Ulysses - Sun polar orbiter/Jupiter flyby, mission still active ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant. /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | |_____|/ |_|/ |_____|/ | ------------------------------ Date: 19 Mar 91 00:20:00 GMT From: cix.compulink.co.uk!printf@ucbvax.Berkeley.EDU (Ian Stirling) Subject: railguns,superguns Here in the UK there was a program on TV,about the iraqi supergun affair ("petrochemical" pipes were actually bits of a massive gun barrel) It talked about the scientist who concieved the idea(orginally for launching objects into LEO) but then went on to design artillery(for example a 60M long barrel mobile gun,1500 or 600KM range)If memory serves the space gun idea was a 1000mm bore gun to shoot objects into LEO with a 10tonne charge of propellant,it was very long,cant remember exact length tho.And worked by having a large gun on rails pointing up a hill(gun moves back to adsorb recoil,Im not sure how this worked,a spring to hold the trains from rolling down the hill?? :-).The program is a serious science program,not known for sensationalism. ------------------------------ Date: 20 Mar 91 22:07:56 GMT From: bloom-picayune.mit.edu!voskhod!davew@bloom-beacon.mit.edu (dave warkentin) Subject: Re: railguns and electro-magnetic launchers In article <1991Mar20.163225.1063@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes: > In article <1991Mar20.013858.16326@ariel.unm.edu> prentice@triton.unm.edu (John Prentice) writes: > >>Nobody's done this with an EM launcher. However, it has been done many > >>times with old-fashioned chemical guns... > > > >The two are not comparable however. EM launchers involve accelerations > >many orders of magnitude larger than chemical guns (or even light gas > >guns). I have seen some railguns push 100 g's in weapons tests... > > Can we see some more precise numbers? Chemical guns routinely hit > *ten thousand* Gs and more. None of the EM-launcher proposals I've seen > have gone higher than that. > -- > "[Some people] positively *wish* to | Henry Spencer @ U of Toronto Zoology > believe ill of the modern world."-R.Peto| henry@zoo.toronto.edu utzoo!henry A quick calculation shows that a shell fired at 45 degrees for a range of 50 km would have a muzzle speed of 700 m/s (no air, flat earth, etc.). This could be attained by a uniform acceleration of 24500 m/s^2 or 2500 G. A rifle slug could reach 1000 m/s (working from an anecdotal "3000 fps") in in a one meter barrel with a uniform acceleration of 500000 m/s^2 or 51000 G. (Reality checks welcome.) In any case, a chemical gun which only had accelerations "many orders of magnitude less" than 100 G would be pretty useless. -- Dave Warkentin davew@sputnik.mit.edu ------------------------------ Date: 22 Mar 91 20:08:59 GMT From: magnus.acs.ohio-state.edu!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@tut.cis.ohio-state.edu (Ron Baalke) Subject: Pioneer 11 Update - 03/22/91 PIONEER 11 STATUS REPORT March 22, 1991 On March 17, the fourth attempt to obtain clock and cone angles of Canopus with the IPP (Imagine Photopolarimeter) instrument was unsuccessful. Each attempt lowered the gain setting by one to reduce the presumed triggering on noise, but the contacts do not appear to be on Canopus. On March 23 and 24 an attempt will be made to lock on the star Vega. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@mars.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |___ M/S 301-355 | Change is constant. /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | |_____|/ |_|/ |_____|/ | ------------------------------ Date: 22 Mar 91 21:51:39 GMT From: diego.llnl.gov@lll-winken.llnl.gov (Tom DeBoni) Subject: Free CRAY time to SISAL users The Sisal Scientific Computing Initiative Contacts: John Feo and Dave Cann The Computer Research Group at Lawrence Livermore National Laboratory (LLNL) announces the Sisal Scientific Computing Initiative (SSCI). The Initiative will award free Cray X-MP time and support to researchers willing to develop their applications in SISAL, a functional language for parallel numerical computation. Members of the Computer Research Group will provide free educational material, training, consulting, and user services. SSCI is an outgrowth of the Sisal Language Project, an eight year effort funded by the Office of Energy Research (Department of Energy) and Lawrence Livermore National Laboratory. SISAL provides a clean and natural medium for expressing machine independent, determinant, parallel programs. The cost of writing, debugging, and maintaining parallel applications in SISAL is equivalent to the cost to writing, debugging, and maintaining sequential applications in Fortran. Moreover, the same SISAL program will run, without modification, on any parallel machine supporting SISAL software. Recent SISAL compiler developments for the Alliant FX/80, Cray X-MP, and other shared memory machines have resulted in SISAL applications that run faster than Fortran equivalents compiled using automatic concurrentizing and vectorizing tools. Interested participants should submit a 1-2 page proposal by May 1, 1991 to Computer Research Group, L-306 Lawrence Livermore National Laboratory P.O. Box 808 Livermore, CA 94450 Proposals should describe the research and explain how the work will benefit from parallel execution on a Cray X-MP. We will announce accepted proposals by June 1, 1991. For more information about the Sisal Scientific Computing Initiative please contact John Feo (feo@lll-crg.llnl.gov) at (415) 442-6389 or Dave Cann (cann@lll-crg.llnl.gov) at (415) 443-7875. We look forward to hearing from you. ------------------------------ Date: 22 Mar 91 22:25:54 GMT From: sco!jjones@uunet.uu.net (Jim Jones) Subject: Re: Space Station 'Fred' Restructuring One of the guys at my gym does development work on the space station project at Lockheed, over the hill in Sunnyvale -- I won't say just what part he worked on, because I don't know how paranoid Lockheed is. Anyway, I'd always ask him how the project was going, and he'd complain about a budget cut or some piece of bureaucratic stupidity, but would never question the project. Come the Fred restructuring and downsizing, I asked him about it. He said that the new configuration was really all that could be reasonably accomplished (a change of tune for him), and could be carried up in four shuttle loads. He said that everybody he worked with on the project, especially his NASA contacts, knew that it would never work as originally planned, but was afraid to say anything earlier in the process for fear that Congress would kill it. I assume that NASA feels the project has enough momentum at this point to carry through. Great. Bureaucracy at its finest. Years of work and billions spent needlessly, but, by God, everybody kept their jobs. -- ____________________________ Jim Jones, jjones@sco.com The Santa Cruz Operation ------------------------------ Date: 23 Mar 91 04:48:37 GMT From: brunix!cs.brown.edu!cs196006@uunet.uu.net (Josh Hendrix) Subject: Re: "Follies" In article <9103220043.AA00349@cmr.ncsl.nist.gov>, roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: |> Before we really get going on this latest round of historical analogies |> (much like the one last year and the one the year before that), might I |> point out that trying to make historical comparisons between two situations |> in which the individual parameters are almost all different is very unlikely |> to produce any useful conclusions? :-) I liken it to the first proto-fish packing up its belongings and deciding to leave the sea behind forever. That's the only truly useful analogy I can think of. Josh Hendrix cs196006@brownvm.brown.edu ------------------------------ End of SPACE Digest V13 #303 *******************