Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_022.TXT

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Date: Tue,  8 Jan 1991 01:58:39 -0500 (EST)
Subject: SPACE Digest V13 #022

SPACE Digest                                      Volume 13 : Issue 22

Today's Topics:
               Re: solar cells
                 NASA images
             Re: MIR sweepstakes
        Re: Recent Newsstand Magazine Articles
         NASA Headline News for 01/03/91 (Forwarded)
       Launch of Navstar GPS II-10 and Shutdown of I-6
               Re: Interstellar travel

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: 3 Jan 91 00:56:48 GMT
From: dweasel![e-mail]  (Loren Petrich)
Subject: Re: solar cells


    The issue of chemical vs. nuclear poisons was brought up yet
again. I feel that this anti-nuclear allergy that too many people have
will someday be remembered as one of the irrational phenomena of our
time. But I doubt that it is worse that the turn-of-the-century
enthusiasm for patent medicines made from radium and other radioactive
materials.

    As to chemical poisons being decomposable, that depends on
what kind of chemical poison. Heavy metals cannot be chemically
decomposed. And some chemical poisons are difficult to decompose, such
as chlorinated hydrocarbons. The persistence of certain pesticides
like DDT should be well known. True, DDT and other such
non-biodegradable substances can be burned at high temperature, but
burning at high temperature is just that.

    I remember some years back that the EPA was hoping to burn
some toxic wastes in a ship at sea, but some environmentalists didn't
like that idea very much.

    I keep on being amazed by the anti-RTG movement. They complain
that those who send up RTG's on spacecraft have not done comprehensive
studies of possible alternatives. Yet I wonder if the anti-RTG people
have done anything similar. Consider the difficulties of doing
maintenance on a spacecraft, which usually cannot be brought back to
its designers. Millions of dollars and months of work go into
designing some spacecraft, so it is important that they be likely to
keep on working. One should try to use components that need as little
maintenance as possible, and RTG's fit the bill very well. They are
continuously "on" and have no moving parts. Solar cells are one common
alternative, but they tend to degrade over time and they cannot be
used in the outer Solar System, due to the extreme dilution of
sunlight there. A focused-sunlight system would have several problems.
A mirror would have to be kept pointing at the Sun, and the generating
system has an abundance of moving parts, which are an all-too-familiar
maintenance headache. There is also the problem of replenishing leaked
working fluid. And I am not aware of any focused-sunlight system that
has ever been used in a spacecraft.

    Chemical reactions are out of the question. Buth fuel and
oxidizer would have to be taken along, which would add a serious
amount of weight for a months-long mission. The power sources usually
have an abundance of moving parts, and would have to be made redundant
for the sake of safety (if one breaks down, the others could keep on
moving). Batteries have a minimum of moving parts, but they usually
have a very low available power to mass ratio (ask any designer of a
battery-powered car). Fuel cells are relatively efficient, but even
they have moving-part problems, and they require liquid hydrogen and
oxygen, which must be kept away from heat. Systems using combustion
can use fuels and oxidizers that are liquid at room temperature, but
they also suffer from problems with moving parts -- consider typical
turbines and piston engines.

    So either solar cells or RTG's are the way to go for
spacecraft. I presume that this is the standard argument.

    In fairness to opponents of nuclear energy, I think that there
is a sociological question to be considered. Most nuclear energy has
been handled as large-scale projects. Simply consider how big a
typical nuclear reactor is and how long it takes to build one. Big
organizations have to justify their policies, and they often make
excuses for keeping on doing what they have been doing. And they
sometimes seem insensitive and arrogant. It's just what computers have
seemed like in their early years, before personal computers became
common.

    And on the issue of safety, one should ask what kinds of
critical tests are possible. It is much easier to perform really tough
tests on an RTG than on a nuclear reactor, so one may feel more
confidence in their safety.

    And another possible difficulty with solar cells -- how much
energy does it take to make them? They would not be too good if the
amount of energy needed to make them was only equal to their output
for several years of running. Has that question ever been addressed?


$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Loren Petrich, the Master Blaster: [e-mail]

Since this nodename is not widely known, you may have to try:

[e-mail]

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

Date: 3 Jan 91 16:19:32 GMT
From: zaphod.mps.ohio-state.edu!samsung!umich!csd4330a!newsserv![e-mail]  (Bob Baskins)
Subject: NASA images


Before the Christmas break I recall seeing posted an Internet address
in which one could get access to NASA images.  Could someone please
email me that address?

Thanks,


--
=====================================================================
Robert Baskins
Environmental Research Institute of Michigan
=====================================================================

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

Date: Thu, 3 Jan 91 08:21:27 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: MIR sweepstakes
Newsgroups: sci.space
Cc:

In article <[e-mail]> you write:
>A better issue is: who is this company that is running the lottery? What
>are their credentials?

I know one of the people involved (Jim Davidson). He has been a very
active supporter of space. He worked for SSI (Space Services), Microsat
(a space startup), and this venture to develop a space tourism market.
In addition, he is active in the local NSS chapter and was on the NSS
bord of directors.

>If they are merely attempting to turn a profit...

I'm sure they would like to make a profit. However, their main goal is
to develop space.

>Or they could be just hoping that the winner takes the alternative prize
>(1.5 million according to one posting).

Jim has told me that SOMEBODY will go regardless. If the winner can't/won't
go, the second place person will go. The only thing which would prevent
the trip would be unforseen political events int he USSR.

BTW, the winner gets a choice of $1.5M or the trip and $500K. Second prize
is $400K and a trip if the winner can't/won't make the trip. There will
be twelve canidates in all.

>I seem to recall Henry Spencer gave a good character reference for one of
>the main guys in the company,

I second Henry's good reference.

>How many dreamers/contestants/suckers have called so far?

According to Jim Davidson, 'tens of thousands'.

   Allen
--
+----------------------------------------------------------------------------+
|Allen W. Sherzer | America does best when it accepts a challenging mission. |
|   [e-mail]   | We invent well under pressure. Conversely, we stagnate   |
|                 | when caution prevails.   -- Buzz Aldrin                  |

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

Date: 2 Jan 91 06:45:03 GMT
From: swrinde!mips!news.cs.indiana.edu!msi.umn.edu!cs.umn.edu!kksys!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Recent Newsstand Magazine Articles

This is one case where I definitely agree with NASA. It seems clear that the
crew survived the explosion, and may well have understood what was going on,
and that they would not survive impact, or drowning. The conversations, etc
would
be extremely distressing to the families. And to many other people as well.
**************************************************************************
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INET: [e-mail]

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

Date: 3 Jan 91 18:52:20 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 01/03/91 (Forwarded)


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

  Thursday, January 3, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Thursday, January 3, 1991

The House Committee on Science, Space and Technology convened this
morning to hear testimony by the chairman of the Advisory Committee on
the Future of the U.S. Space Program, Norman Augustine, and the panel's
vice chairman, Laurel L. Wilkening.  The chairman's opening remarks
outlined the basic findings of the Committee and its five basic
goals:   A balanced space program predicated on space science; a
mission to planet Earth; a mission from planet Earth, a strong effort
in maintaining the technology base; and a robust space transportation
system.


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


At Venus, the Magellan spacecraft continues to perform normally on its
survey mission of Earth's sister planet.  Magellan has orbited Venus
about 700 times and data from 677 orbits have been successfully
received on Earth.

Problems with tape recorder A aboard Magellan before the holidays led
controllers to implement a plan using only the B- side data recorder.
With one recorder, each image swath now has three small gaps in it, as
the recorder switches from track to track.  A few bad frames still
occur with the B-side recorder, however the rate of bad image frames
has dropped, and the amount of usable data has significantly increased
with the new strategy.

Commands sent to the spacecraft during the holidays were performed
without incident, and a new command sequence will be sent to Magellan
tomorrow.


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


At Kennedy Space Center, technicians are now working on all three
orbiters, preparing them for their respective missions.  In the Vehicle
Assembly Building, workers have begun preparations for post-flight
inspections of Columbia's aft engine compartment and crew module, and
booster stacking for STS-37 continues.  Discovery power up continues in
the Orbiter Processing Facility, and installation of the Forward
Reaction Control System is scheduled to begin tonight.  Installation of
the number three APU on Atlantis continues, and the shuttle's robot arm
is scheduled to be installed this weekend.




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


Thursday, 1/3/91

 12:30 pm NASA Update -- The Year in Review, Part 2

  1:00 pm Testimony of the chairman of the Advisory Committee
      on the Future of the U.S. Space Program before
      the House Committee on Science, Space, and Technology
      (Recorded playback of the morning's live Program)

  6:00 pm     NASA Update -- The Year in Review, Part 2,
    followed by:

      Testimony of the chairman of the Advisory Committee
      on the Future of the U.S. Space Program before the House
      Committee on Science, Space, and Technology
      (Recorded playback of the mornings live Program)

Friday, 1/4/91     No scheduled programming


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:        Wed, 02 Jan 91 17:08:18 AST
To: [e-mail]
From: [e-mail]([e-mail] Langley)
Subject:     Launch of Navstar GPS II-10 and Shutdown of I-6

The 10th Navstar GPS Block II satellite, PRN 23, was launched on 26
November 1990 into the E-plane, and was made available on 10 December.
Satellite I-6,PRN 9, has been set unusable since 11 December 1990.  The
updated Navstar GPS Constellation Status table given below reflects
these events.

                        Navstar GPS Constellation Status
                                   (91-01-02)

Blk                       NASA   Orbit
II        PRN Internat. Catalog  Plane   Launch
Seq   SVN Code   ID      Number  Pos'n    Date   Clock        Comment
--------------------------------------------------------------------------------
Block I
       1   4  1978-020A  10684          78-02-22      Not usable since 85-07
       2   7  1978-047A  10893          78-05-13      Not usable since 85-09
       3   6  1978-093A  11054    A-3   78-10-06  Rb
       4   8  1978-112A  11141          78-12-10      L-band signals turned
                                                       off 89-10-14
       5   5  1980-011A  11690          80-02-09      Not usable since 84-05
       6   9  1980-032A  11783    A-2   80-04-26  Rb  Operating on 2nd Rb clock;
                                                       set unusable 90-12-11
       7                                81-12-18      Launch failure
       8  11  1983-072A  14189    C-3   83-07-14  Cs
       9  13  1984-059A  15039    C-1   84-06-13  Cs
      10  12  1984-097A  15271    A-1   84-09-08  Cs
      11   3  1985-093A  16129    C-4   85-10-09  Rb  operating on Rb clock
                                                       without temp. control

Block II
II-1  14  14  1989-013A  19802    E-1   89-02-14  Cs  Became available 89-04-15
II-2  13   2  1989-044A  20061    B-3   89-06-10  Cs  Became available 89-08-10
II-3  16  16  1989-064A  20185    E-3   89-08-18  Rb  Became available 89-10-14
II-4  19  19  1989-085A  20302    A-4   89-10-21  Cs  Became available 89-11-23
II-5  17  17  1989-097A  20361    D-3   89-12-11  Cs  L-band signals enabled
                                                       90-01-06
II-6  18  18  1990-008A  20452    F-3   90-01-24  Cs  Became available 90-02-14
                                                       22:26 UT
II-7  20  20  1990-025A  20533    B-2   90-03-26  Cs  Became available 90-04-18
                                                       23:13 UT
II-8  21  21  1990-068A  20724    E-2   90-08-02  Cs  Became available 90-08-22
                                                       15:00 UT
II-9  15  15  1990-088A  20830    D-2   90-10-01  Cs  Became available 90-10-15
                                                       00:39 UT
II-10 23  23  1990-103A  20959    E-4   90-11-26  Cs  Became available 90-12-10
                                                       23:45 UT

Notes
1.  NASA Catalog Number is also known as NORAD or U.S. Space Command object
    number.
2.  No orbital plane position = satellite no longer operational.
3.  Clock:  Rb = Rubidium; Cs = Cesium
4.  PRN 16 is scheduled to switch to a Cs clock early in 1991.

================================================================================
 Richard B. Langley                            BITnet: [e-mail] or [e-mail]
 Geodetic Research Laboratory                  Phone:  [phone]
 Dept. of Surveying Engineering                Telex:  014-46202
 University of New Brunswick                   FAX:    [phone]
 Fredericton, N.B., Canada  E3B 5A3
================================================================================

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

Date: 2 Jan 91 06:45:02 GMT
From: zaphod.mps.ohio-state.edu!mips!news.cs.indiana.edu!msi.umn.edu!cs.umn.edu!kksys!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Interstellar travel

Clearly a Pliestocene civilization has already depleated the local fuel
stores.

:-)

**************************************************************************
Zeitgeist Busters!
UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

End of SPACE Digest V13 #022
*******************