Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_039.TXT

Internet Message Format | 1991-06-28 | 17KB

Return-path: <[e-mail]>
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/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/kbY0RbW00VcJI0u04r>;
          Sun, 13 Jan 1991 02:08:24 -0500 (EST)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sun, 13 Jan 1991 02:07:52 -0500 (EST)
Subject: SPACE Digest V13 #039

SPACE Digest                                      Volume 13 : Issue 39

Today's Topics:
              Re: US buys Soviet reactor
         NASA Headline News for 01/10/91 (Forwarded)
        Re: LOX/LH2 in the Shuttle Payload Bay
          Re: LOX/LH2 in Shuttle Payload Bay
             Re: Salyut Question
               Re: Interstellar Travel
           Re: Humankind's Second Off-world Colony
             NASA Authorization Act 1991?
               Salyut 7 burn-up
      What are the qualifications needed for astronauts
              Magellan Update - 01/10/91

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: 10 Jan 91 00:34:07 GMT
From: zephyr.ens.tek.com!tektronix!reed![e-mail]  (Bill Trost,Box 607,ext 640,)
Subject: Re: US buys Soviet reactor

A long time ago, in article <[e-mail]>,
[e-mail] (Stewart T. Fleming) writes:
>WASHINGTON - In the first US-Soviet transfer of sensitive military
>technology, the United States is buying an advanced nuclear reactor
>from the Soviet Union.
....
>I have some questions about this :
>
>It would appear that there is (strong ?) political opposition to the
>use of nuclear reactors in space, at least on the US side....

In the last (January?) _Ad Astra_, it was reported that the lawsuit of
the "Florida Coalition of Peace and Justice" (maybe not "Florida", and
maybe a different group -- that wonderful name just stands out)
attempting to block the launch of _Ulysses_ on the grounds of its RTG
was thrown out of court "with extreme prejudice," meaning that the
courts refuse to be bothered by something like this again.  NSS is
quick to point out the various documents and testimony they filed to
help bring about this ruling.  There was still a protest at the
launch, and the NSS staged a counterprotest.

I interpret this as meaning that the no-nukes-in-space folks are
having "a tough time of it."

>Is the power output of the Soviet reactor considerably greater than
>any US one?  As I understand it, most US satellites are
>solar-powered....

I'm not certain about satellite uses, but nuclear power sources are
used for long-distance probes (such as _Ulysses_), mostly because
there ain't that much sun way out, and possibly for reliability
reasons --- solar cells have to be exposed in order to function and
are therefore subject to damage from debris, whereas an RTG can (and
must be, for safety reasons) be encased.

Bill Trost
[e-mail], but probably [e-mail]

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

Date: 10 Jan 91 21:47:22 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 01/10/91 (Forwarded)


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

  Thursday, January 10, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Thursday, January 10, 1991

The National Space Council meets today.  Adm. Truly will
present the Council with NASA's Action Plan on the Future of the
U.S. Space Program.

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

Preparation of Discovery, for the upcoming STS-39 flight,
continues at Kennedy Space Center's Orbiter Processing Facility.
Leak and functional tests of Discovery's three auxiliary power units
are now planned for later this week.  Tests of the onboard closed
circuit television system have been completed.

Tests of the recently-installed Remote Manipulator System in
Atlantis' payload bay were completed and were successful.  In the
crew cabin area, window's 1 and 6 are to be replaced because of
blemishes.  Orbiter instrumentation system and power reactant
storage and distribution system testing is still underway, and is
expected to be completed by the end of the week.

Tile replacement and inspection continues in the Vehicle
Assembly Building on Columbia.  Roll-around tires have been
installed on Columbia's gear to enable landing gear doors to be
cycled for tile inspection.

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

Magellan has now orbited over 50 percent of the Venus
surface since its radar mapping mission began last fall.  On Feb. 1,
Magellan will have imaged fully one half of the planet with its
radar system.  Ninety percent of the planet is expected to be
mapped by May 24, at the current mapping rate.  Meanwhile, the
B-side data tape recorder remains off while Jet Propulsion
Laboratory engineers continue to analyze problems with that
recorder.  The use of a single data recorder causes small gaps in the
radar data coverage.  These gaps, each about a dozen miles in
length, represent less than one percent of the area of a single
mapping swath.  Other than the tape recorder problem, the
spacecraft is performing nominally and all star calibration and
momentum wheel desaturation operations have been accomplished
with no hitches.

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

NASA recently modified its contract with Rockwell Space
Division, for the development of OV-105, Endeavour, to include the
design, fabrication and installation of an orbiter drag chute
system.  The price of the modification is $33.3 million and brings
the OV-105 contract value up to $1.8 billion.  The drag chutes will
be deployed upon orbiter touchdown, and are intended to
supplement main gear braking to improve the landing capabilities
of the orbiter on shorter runways.

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

A series of preflight briefings for the Discovery STS-39
mission will be held Jan. 23 and 24 at the Johnson Space Center.
This is the first unclassified Department of Defense shuttle mission.
The briefings will begin at 9:30 am on the 23rd and will be carried
on NASA Select TV.



Here's the broadcast schedule for Public Affairs events on NASA
Select TV.  All times are Eastern.  **indicates a live program.

Thursday, 1/10/91
    11:30 am    NASA Update will be transmitted.

    12:00 pm    Discovery Lecture Series features "The Infinite
                    Voyage."

     1:00 pm    NASA Productions features "Sail on Voyager."



All events and times may change without notice.  This report is
filed daily, Monday through Friday, at 12:00 pm, EST.  It is a
service of Internal Communications Branch at NASA
Headquarters.  Contact:  CREDMOND on NASAmail or at 202/453-
8425.


NASA Select TV:  Satcom F2R, Transponder 13, C-Band, 72 degrees
West Longitude, Audio 6.8, Frequency 3960 MHz.

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

Date: 10 Jan 91 21:51:00 GMT
From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: LOX/LH2 in the Shuttle Payload Bay

In article <[e-mail]> dbm0000@sei_4.lerc.nasa.gov (Dave McKissock) writes:
>Shuttle Centaur would have had approximately 40,000 pounds of fuel on-board.
>This load, in addition to the weight of the Centaur structure,
>mounting support structure, and the payload, would have exceeded the
>return-to-launch-site abort weight restrictrictions of the Shuttle (for
>one example).

So how did solid rockets -- which one would expect to weigh more, given
their considerably lower specific impulse -- satisfy those weight limits
for launching two out of the three original Shuttle-Centaur payloads?
Both Ulysses and Magellan, originally both slated for S-C, flew their
original flight plans, or close approximations thereto, with solids.
How did those missions meet the weight limits if Shuttle-Centaur
versions of those missions couldn't?

Unless Centaur's dead weight is horrendous, which would surprise me
greatly, offloading enough fuel to stay within the landing weight limits
should still give an upper stage with considerably better performance
than solids.  It might not have been enough to launch Galileo on its
original flight plan, since Galileo badly needed a trip to the fat
farm :-), but I expect it could have done better than the VEEGA plan
that had to be adopted for use with an IUS.  And unless something is
screwy somewhere, it should have been fine for Ulysses and Magellan.

I *still* stick to my guns:  there was no rational reason to kill
Shuttle-Centaur.  Staying within the weight limits, to eliminate the
problematic propellant dumping, would certainly reduce its utility
a little but should not have destroyed it.
--
If the Space Shuttle was the answer,   | Henry Spencer at U of Toronto Zoology
what was the question?                 |  [e-mail]   utzoo!henry

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

Date: 9 Jan 91 03:21:47 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: LOX/LH2 in Shuttle Payload Bay

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>
>>Of course the real question is why put it on the Shuttle in the first
>>place. After all, administration policy AND public law both mandate
>>that this sort of payload go up on an expendable. Why is the Shuttle
>>still in the satellite launch buisness?
>
>Why are you assuming satellites?  Centaurs are nifty for launching
>interplanetary probes; Galileo was scheduled to go up on one, until the
>Challenger accident intervened.

There is no reason interplanetary probes should be treated any differently
than industrial satellites.  The law covering industrial satellites should
be extended to planetary probes and most DoD satellites, IMHO.



--
Nick Szabo            [e-mail]
Embrace Change...  Keep the Values...  Hold Dear the Laughter...

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

Date: 9 Jan 91 17:14:08 GMT
From: mojo![e-mail]  (Doug Mohney)
Subject: Re: Salyut Question

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Leo Wikholm) writes:
>>  How big is the Salyut-7 Space Station?
>
>About the size of one Mir module.  Rather smaller than Skylab.  You could
>more or less fit it into a shuttle payload bay, I think.

Sovs. had plans to bring it back in Buran, nice piece of hardware to look at
for long term exposure to space environment.

 Doug Mohney, Operations Manager, CAD Lab/ME, Univ. of Maryland College Park
            *  Ray Kaplan was right *

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

Date: 9 Jan 91 20:57:43 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Interstellar Travel

>>    Perhaps it can do a flyby, and do a 180 turn through the gravity well,
>>and return to us...
>
>Not very likely at interstellar speeds, unless the star is a neutron star.
>Getting close to a 180 -- you can't actually get 180 unless you pull some
>other trick -- requires a very close approach to the center of mass, which
>will take you straight into an ordinary star.

But if you visit a binary, you might pull a couple of 90's.  Or visit
two or three neighbor stars (what else have you got to do out there) and
concoct some fancier polygon.

--
Thank God for atheism!        8=8=8=8          Tom Neff / [e-mail]

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

Date: 10 Jan 91 11:27:04 GMT
From: bu.edu!rpi!uupsi!sunic!lth.se![e-mail]  (Magnus Olsson)
Subject: Re: Humankind's Second Off-world Colony

In article <[e-mail]> [e-mail] (Jon Monsarrat x6227) writes:
>Where should Man's first colony after a moon colony be?
> OUR GUESS: Ganymede because of its water supply and proximity to Jupiter
>  which is a good source of gases possibly used in fusion. Also I read
>  about it in a very old Heinlein book! :)
>
>What would the motivations for having a colony be?
> OUR GUESS: Less hostile environment than moon.

But what about the radiation level? If I recall correctly, all the Galilean
moons are essentially inside Jupiter's van Allen belts which means the
radiation levels (mainly protons) on Ganymede would be lethal.


And is there any special reason for skipping Mars - the "obvious" place for
a second colony? Mars has a much more benign environment than Ganymede (even
without radiation) - e.g., the temperature range, though a bit on the cold side,
is still easier to handle than the temperature at Ganymede. And of course
the cost of transporting people and equipment to mars is much lower, and it takes
a much shorter time to get there (with today's technology, on the order of a year
or so to Mars, five years to Jupiter).

Magnus Olsson                   | \e+      /_
Dept. of Theoretical Physics    |  \  Z   / q
University of Lund, Sweden      |   >----<
Internet: [e-mail]     |  /      \===== g
Bitnet: THEPMO@SELDC52          | /e-      \q

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

Date: 10 Jan 91 01:42:03 GMT
From: munnari.oz.au!metro!cluster!ultima!phobos![e-mail]  (Dan Corbett)
Subject: NASA Authorization Act 1991?

[e-mail] ("Allen W. Sherzer") writes:

>[Centaur on Shuttle stuff deleted] ALL payloads are covered under the NASA
>Authorization Act of 1991 AND the administrations space policy from
>the mid 80's. The only exception is for payloads which require a
>human presence. I don't think Galileo qualifies.

What is this Act?  It must have been passed in the last week.  I think
many of us would appreciate a summary posted to the net by a knowledgable
person.

----------------------------------------------------------------------------
Dan Corbett
University of Technology, Sydney
----------------------------------------------------------------------------

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

Date: Wed, 9 Jan 91 07:27:04 PST
From: [e-mail] (Troy T. Pummill)
Subject: Salyut 7 burn-up


At what altitude will Salyut strike 'the upper atmosphere' and being
to burn-up?


-------------------------------------------------------------------------------
|  Troy T. Pummill         |  [e-mail]                              |
|  Sr. Technical Instructor      |  ...uunet!lanslide.hls.com!trop            |
|  Hughes LAN Systems            |                                            |
|  [phone]                |  1225 Charleston Rd., Silicon Gulch        |
|  Mountain View, CA  94043     |  The preceding drivel is entirely my own!  |
------------------------------------ ------------------------------------------

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

Date: 10 Jan 91 20:03:18 GMT
From: sdcc6!sdcc13![e-mail]  (Matt Harrington)
Subject: What are the qualifications needed for astronauts

I know that to be a fighter pilot, one must meet rigorous
physical and mental requirements.  Does anyone know the
requirements for astronauts?  For example, do they need to
have perfect vision?  Do they need to be fighter pilots
first?  From where are the people chosen, an academy?

-Matt Harrington

--
Matthew B. Harrington                        Internet: [e-mail]
University of California at San Diego
Department of Biophysics                     Think! It's not illegal
       Ask me about my Mac SE for sale !                     yet.

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

Date: 10 Jan 91 21:09:27 GMT
From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 01/10/91


                        MAGELLAN STATUS REPORT
                          January 10, 1991

     The Magellan spacecraft is performing nominally.  All STARCALS (star
calibrations) and DESATS (desaturations of the reaction wheels) during the
past 24 hours were successful.

     Magellan is presently completing its 754th mapping orbit on its 103rd day
of radar mapping operations.  It takes 243 days for Venus to turn once under
the spacecraft orbit.  Each day Magellan completes 7.3 orbits, so by the time
we get back over the starting point of our mapping we will have almost 1800
image strips.

     Even now we have images of more Venus surface than the total land area of
the Earth.  The two planets are about the same size, but 75% of the Earth is
covered by water.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

End of SPACE Digest V13 #039
*******************