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Date: Fri, 15 Mar 91 01:52:33 -0500 (EST)
Subject: SPACE Digest V13 #269

SPACE Digest                                     Volume 13 : Issue 269

Today's Topics:
        Re: Space Flight Acceleration Regimes
Re: German conference highlights doubts about ESA's manned space plans
              Re: Space Profits
                  Re: Thrust
         NASA Headline News for 03/12/91 (Forwarded)
            Re: O-Ring and Feynman
                   Re: Gaia
              Arcjet Release (Forwarded)
        Re: Space Station 'Fred' Restructuring

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: 13 Mar 91 01:25:43 GMT
From: elroy.jpl.nasa.gov!jato![e-mail]  (Van Snyder)
Subject: Re: Space Flight Acceleration Regimes

Bunch of stuff about centrifugal acceleration compensating for linear
acceleration deleted ....

There have been SF stories about using condensed matter, i.e. neutronium,
to create a gravitational field to compensate for high acceleration.  Of
course, the mass of this stuff is enormous, and adds to the crud you need
to push around.  Bob Forward at Hughes has written some more serious articles
about using masses to level out the microgravity field, i.e. so the
gravitational potential is the same to within nano-g's in a small volume, say
a cubic meter or so.


--
[e-mail]
ames!elroy!jato!vsnyder
[e-mail]

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

Date: 13 Mar 91 01:01:49 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: German conference highlights doubts about ESA's manned space plans

In article <[e-mail]> [e-mail] (Dave Smith) writes:
> >[I write]
> >Or, if you prefer not to pay the $1,000,000++/hour cost of an EVA, you
> >could make sure it works before you launch it.
> >
>
>This is a screamer.  What do you do at Sequent, Nick?  Work in marketing?

This is a screamer. :-)  I work in testing, making sure our products work.
Not to brag, but Sequent's main selling point is our quality statistics,
such as up-time.   Sequent repairmen are about as common as Maytag
repairmen. :-)  Even so, when needed they can do the job for about
1/20,000th the cost of our vaunted astronauts.

Now back to the regularly scheduled space.flamefest.  :-)



--
Nick Szabo            [e-mail]
"If you want oil, drill lots of wells" -- J. Paul Getty
The above opinions are my own and not related to those of any
organization I may be affiliated with.

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

Date: 7 Mar 91 18:54:50 GMT
From: elroy.jpl.nasa.gov!sdd.hp.com!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss![e-mail]  (Paul Blase)
Subject: Re: Space Profits


>>Gold and silver in large amounts did
>>not start flowing from America for nearly 50 years.

 "W> Exactly. No profit making enterprise would ever have funded the
 "W> colonization of the new world. Payoff time was just too long.
 "W> Under your system where every step must make buisness sense the
 "W> new world would never have been colonized.

But every mission to the "New World" was funded with profit in mind.  I think
that we need to differentiate between "colonization" and "settlements".  The
first Spanish settlements were not self-sustaining communities, for the most
part the men left their families in Spain.  They came over with the express
purpose of making as much money as possible (by exploiting and/or
conquering the natives) and then going home. Later, the
colonies were started, with farmers, families, etc.  Most of these, by the
way, were started for religous purposes or, similiar to Australia, as
prison colonies.

--- via Silver Xpress V2.26 [NR]
--
Paul Blase - via FidoNet node 1:129/104
UUCP: ...!pitt!nss!Paul.Blase
INTERNET: [e-mail]

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

Date: 12 Mar 91 14:01:59 GMT
From: isis!isis![e-mail]  (Glenn A. Serre)
Subject: Re: Thrust

John Roberts:
Another method that has been mentioned is launching water from Earth, then
using solar energy to convert it to hydrogen and oxygen for use in a
conventional engine. Because of its greater density, the water should be
much cheaper to launch than LOX/LH2. It might be possible to save even

Me:
I thought that the Space Station (Fred) was at one time going to use this
scheme.  Has this been abandoned?
--

--Glenn Serre
[e-mail]
--

--Glenn Serre
[e-mail]

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

Date: 12 Mar 91 17:46:31 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: NASA Headline News for 03/12/91 (Forwarded)


             Headline News
Internal Communications Branch (P-2) NASA Headquarters

  Tuesday, March 12, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Tuesday, March 12, 1991

Kennedy Space Center technicians powered up the Atlantis
yesterday and are now carrying out the orbiter interface test.  Today's
activities include leak checks and the installation of a few outstanding
thermal protection system tiles.  The frequency response test is
scheduled for tomorrow.  Atlantis and its STS-37 stack are presently
on a schedule which would support rollout of the mobile launch
system to launch pad 39-B in the early morning hours of
Friday, March 15.  STS-37's payload, the Gamma Ray Observatory,
was installed in the payload cannister last night and should be in the
pad 39-B payload changeout room by daybreak tomorrow.  GRO could
be installed into Atlantis' payload bay by late this weekend.  The
terminal countdown demonstration test for STS-37 is scheduled
for March 19 and 20.  The STS-37 flight readiness review is currently
set for March 26 and 27.

KSC technicians expect to begin the demate procedures on the
STS-39 stack today.  Discovery's removal from the external tank
should occur about 4:00 pm this afternoon.  If the demate procedure
goes smoothly, Discovery will be rolled back into the orbiter processing
facility about 9:00 am Thursday, March 14.

Columbia, still in the orbiter processing facility, is awaiting
installation of the Spacelab habitable module for its STS-40
Spacelab Life Sciences mission.  The module is presently in the
Operations and Checkout Building and will be moved to the OPF next
week for installation into Columbia's payload on March 23.

                   * * * * * * * * * * * * * * * *

The NASA honor awards ceremony takes place this afternoon at
2:00 in the Health and Human Services auditorium at 4th and
Independence Avenue.  Administrator Richard Truly and Associate
Deputy Sam Keller will present 55 individual and 16 group awards.
Noted author, historian, and Librarian of Congress Emeritus,
Daniel Boorstin will address the group.
                   * * * * * * * * * * * * * * * *

The House Subcommittee on Technology and Competitiveness
(Committee on Science, Space and Technology), and the House
Subcommittee on Research and Development (Committee on
Armed Services) today will hold a joint hearing on NASA's FY 1992
budget request for the National Aero-Space Plane.  Participants will
include NASA Deputy J.R. Thompson, and Dr. Allan Bromley, White
House Science Advisor.  The hearing is at 1:30 p.m. in the Rayburn
House Office Building.  The event will be videotaped for replay on
NASA Select TV.

                   * * * * * * * * * * * * * * * *

On Thursday and Friday, March 14 and 15, the American
Astronautical Society is hosting its 29th Goddard Memorial
Symposium.  The theme is "Humans and Machines in Space:  The
Vision, The Challenge, The Payoff," and focuses on the synergistic
relationship between people and machines.  Adm. Truly will deliver
the keynote speech on Thursday.  James Beggs will chair the
session on "The Vision," J.R.JThompson will chair the session on "The
Challenge," and Lt. General James Abrahamson will chair the
session on "The Payoff."  John Noble Wilford, New York Times
science writer and two-time Nobel Prize winner, is the general
chairman.  The sessions led by James Beggs, J.R. Thompson, and
James Abrahamson, and the keynote remarks by Adm. Truly will be
videotaped for replay on NASA Select TV.


Here's the broadcast schedule for Public Affairs events on NASA Select
TV.  All times are Eastern.  NASA Select TV is carried on GE Satcom
F2R, transponder 13, C-Band, 72 degrees W Long., Audio 6.8,
Frequency 3960 MHz.

Tuesday, 3/12/91
    12:00 pm    Starfinder program "Fusion Energy."

    12:15 pm    Stennis Space Center 1991.

    12:30 pm    History of Space Travel "Astronauts: U.S.
          Project Mercury."

    1:00 pm    The Infinite Voyage series, "Miracles by Design."

Wednesday, 3/13/91
    1:15 pm    Magellan-at-Venus report live from Jet
          Propulsion Laboratory.

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

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

Date: 13 Mar 91 01:51:27 GMT
From: skipper![e-mail]  (Mary Shafer)
Subject: Re: O-Ring and Feynman

In article <[e-mail]>, [e-mail] (Greg Roberts) says:
>
>I have the most absolute respect for Feynman. He took at the technical mumbo
>jumbo from the MT engineering staff, and made it crystal clear so that anyone,
>including Neil Armstrong, could understand it. Temperature. O-Ring. Failure.

And what the hell do you mean by "anyone, including Neil Armstrong, could
understand it"?

Is this a snotty little sneer at astronauts?

You should be ashamed of yourself.  Keep your inferiority complex
under better control--just because you're not an astronaut, it's not
necessary to insult those who are.
--
Mary Shafer  [e-mail]  ames!skipper.dfrf.nasa.gov!shafer
           NASA Ames Dryden Flight Research Facility, Edwards, CA
                     Of course I don't speak for NASA
 "A MiG at your six is better than no MiG at all"--Unknown US fighter pilot

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

Date: 10 Mar 91 05:57:28 GMT
From: munnari.oz.au!metro!socs.uts.edu.au![e-mail]  (Dan Corbett)
Subject: Re: Gaia

[e-mail] (Larry Wall) writes:

>In article <[e-mail]> [e-mail] (John Roberts) writes:

>: What part of Gaia is its appendix? :-)

>Hmm, something that uses resources but doesn't contribute to the good of
>the whole, and is, in fact, occasionally destructive?  I'll have to
>think about that one...  :-)



Politicians?

------------------------------------------------------------------------------
Dan Corbett
Department of Computer Science
University of Technology, Sydney
Sydney, New South Wales, Australia
------------------------------------------------------------------------------

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

Date: 14 Mar 91 16:22:06 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Arcjet Release (Forwarded)

Sarah Keegan
Headquarters, Washington, D.C.                          March 14, 1991
(Phone: [phone])

Linda S. Ellis
Lewis Research Center, Cleveland, Ohio
(Phone: [phone])


RELEASE: 91-39

ARCJETS YIELD BETTER PERFORMANCE, LONGER SATELLITE LIFE

        NASA's Lewis Research Center, Cleveland, has the lead role in
developing the arcjet thruster technology recently selected for
stationkeeping use on AT&T's Telstar 4 communications satellites.

        Arcjet systems offer a significant improvement in propellant use
over chemical and other electrically-augmented thrusters. The savings
realized can be used to increase a satellite's on-orbit lifetime or
payload mass.  Alternatively, launch mass can be decreased so that a
smaller rocket booster can be used.

        The arcjet research and technology program at Lewis Research Center
began in 1983.  A major objective was to bring advanced electric propulsion
to operational status.  This included component research necessary to
demonstrate the required performance, life and integration issues associated
with the arcjet system.

        In an arcjet, a direct current electrical arc is used to heat the
decomposition products of hydrazine propellant to very high temperatures.
Although the arc core temperature can reach 31,123 degrees F, the nozzle walls
are protected by a cool gas boundary layer.

        The hot, slightly ionized gas exits the rocket nozzle at an average
velocity 1.5 to 2 times that attained in conventional thrusters.  For example,
the 1.8 kW arcjet systems developed by Rocket Research Co. (RRC), Redmond,
Wash., for the Telstar 4 program, provide a specific impulse (thrust divided by
the propellant consumption rate) of about 500 seconds.

        This compares to a state-of-the-art resistojet system (another type of
electrical thruster) that would provide 300 seconds of specific impulse for the
same task.  The 1.8 kW design is modeled closely after a flight-type 1.4 kW
system developed by RRC under a Lewis-sponsored program.

        Switching to arcjet systems for north-south stationkeeping on a
geosynchronous communications satellite can reduce propellant requirements by
several hundred pounds.  This savings can extend satellite lifetime by more
than 50 percent or allow the satellite to shift to a less powerful, less
expensive launch vehicle.

        The arcjet technology developed by NASA's Lewis Research Center and
U. S. industry is the most advanced in the world.  The Telstar 4 thrusters are
the only arcjets accepted for operational use on a spacecraft.

        Lewis and industry continue to study arcjet thruster systems and their
interactions with host spacecraft systems.  Results to date suggest that
electromagnetic interference with satellite systems should be minimal and that
there will be no problem sending radio signals through the thruster exhaust
plume.

        Lewis researchers also are investigating a range of power options to
enhance the versatility of hydrazine arcjet technology.  Examples include low
power (1 kW) systems for power-limited satellites and high specific impulse
systems for advanced communications satellites.  The use of high specific
impulse hydrogen arcjet systems also is being explored for primary propulsion.

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

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

Date: 13 Mar 91 20:30:57 GMT
From: rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: Space Station 'Fred' Restructuring

Where can I get pictures of the new 'Fred' configuration?

Phil

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

End of SPACE Digest V13 #269
*******************