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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
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

----------------------------------------------------------------------

Date: 20 Mar 91 08:32:57 GMT
From: elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: JPL spacecraft

>In article <[e-mail]> [e-mail] (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         | [e-mail]
     | | | |  __ \ /| | | |      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![e-mail]  (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![e-mail]  (dave warkentin)
Subject: Re: railguns and electro-magnetic launchers

In article <[e-mail]>,
[e-mail] (Henry Spencer) writes:
 > In article <[e-mail]>
[e-mail] (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|  [e-mail]
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
[e-mail]

------------------------------

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![e-mail]  (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         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | Change is constant.
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 |
 |_____|/  |_|/       |_____|/                      |

------------------------------

Date: 22 Mar 91 21:51:39 GMT
From: [e-mail]  (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 ([e-mail]) at [phone]
or Dave Cann ([e-mail]) at [phone].  We look forward to
hearing from you.

------------------------------

Date: 22 Mar 91 22:25:54 GMT
From: sco![e-mail]  (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, [e-mail]
The Santa Cruz Operation

------------------------------

Date: 23 Mar 91 04:48:37 GMT
From: brunix!cs.brown.edu![e-mail]  (Josh Hendrix)
Subject: Re: "Follies"

In article <[e-mail]>, [e-mail] (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
[e-mail]

------------------------------

End of SPACE Digest V13 #303
*******************