Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_5/V13_560.TXT

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Subject: SPACE Digest V13 #560

SPACE Digest                                     Volume 13 : Issue 560

Today's Topics:
           Re: Mir Sweepstakes - Cancelled
         NASA Headline News for 05/14/91 (Forwarded)
              Re: Why the space station?
             Re: Shuttle launches
         Re: New Subject--Solar Collectors/Antimatter
             Re: Shuttle launches
               Re: Saturn V and the ALS
         Re: New Subject--Solar Collectors/Antimatter
          Re: SPACE STATION FREEDOM WOUNDED

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: 14 May 91 17:35:29 GMT
From: stanford.edu!leland.Stanford.EDU!pangea.Stanford.EDU![e-mail]  (Rick Ottolini)
Subject: Re: Mir Sweepstakes - Cancelled

Remember Heinlein's "Have Spacesuit, Will Travel" novel?
The protagonist wins a spacesuit in a contest and accidently goes
on a galactic adventure.
This captures the excitement of the Mir contest.

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

Date: 14 May 91 17:33:04 GMT
From: [e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 05/14/91 (Forwarded)


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

  Tuesday, May 14, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Tuesday, May 14, 1991 . . .

NASA space flight managers yesterday selected May 22 as the target
launch date for Columbia and the STS-40 Spacelab Life Sciences
mission.  The launch window opens on Wednesday, May 22, at 8:00 am
and extends until 10:00 am EDT.  Mission duration is expected to be just
over nine days with a nominal end-of-mission landing at Edwards Air
Force Base, Calif., on May 31 at 11:51 am EDT.  Current activity at the
Kennedy Space Center includes final orbiter closeout activities on
Columbia and launch control complex preparations for the call to stations
this weekend.

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

NASA Administrator Richard Truly yesterday announced the creation of
a new Systems Analysis and Concepts Office at NASA
Headquarters.  James D. Bain was also named as director of the new
office, which will provide independent and non-advocate decision support
to the Administrator.  The new office will focus on policy alternatives and
on the conceptual and formulative stages of new programs.  It is another
step in NASA's implementation of the recommendations of the
Advisory Committee on the Future of the U.S. Space Program, headed by
Norman Augustine.

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

Goddard Space Flight Center reports that the calibration of
instruments aboard the Gamma Ray Observatory is going well and
will conclude tomorrow.  On Thursday, May 16, the GRO science
operations will begin.  Phase 1 of the science observation is a full-sky
survey of gamma ray sources which is expected to take 15 months to
complete.  All spacecraft systems are reported in nominal condition.

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

The Tracking and Data Relay Satellite-E is currently undergoing
spacecraft fitness checks at Kennedy Space Center.  The astronaut crew
payload inspection will occur next Monday and a spacecraft end-to-end test
will begin on May 29.  Presently, KSC expects to install the TDRS with
inertial upper stage into Atlantis' payload bay by the end of June.  Atlantis'
STS-43 mission to deploy the TDRS-E spacecraft is the next mission after
Columbia's STS-40 flight.

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

NASA-816, the Convair F-106B which Langley Research Center made
famous as its "lightning strike" vehicle, was retired recently and will be
transferred to the new Virginia Air and Space Center in Hampton.  The F-
106 has for the past 12 years flown vortex research and storm
hazard missions for Langley, and in that time has been struck more
than 700 times by lightning while aloft.  It was used by Lewis Research
Center in the 70s as a supersonic transport research plane and prior to
that flew nine years as an Air Force research plane.  It was the last F-106
flying and was the second Consolidated Vultee aircraft to use the Langley-
designed "area rule"fuselage.  The F-102, Convair's predecessor to the 106,
was the first to use the Langley Coke-bottle shape, which made level-
flight supersonic speed practical.

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


Marshall Space Flight Center reports that its three Spacemobile
lecturers last month visited 31 schools in their region reaching a
student audience of over 24,000.  The center also provided educational
support for Kentucky Space Week, a week-long state-sponsored program
modeled after the very successful Tennessee Space Week.  Marshall also
reports that their online educational database - Spacelink - now has over
5,600 registered users, 2,300 of whom indicate they are teachers or
students.  The electronic system received a record 7,500 calls during April,
which Marshall attributes to interest in the STS-39 mission.

Stennis Space Center reports that its Community Leader Briefing was
successful with more than 70 community leaders in the Mississippi
Gulf Coast and Louisiana Delta region attending.  Stennis followed the
briefing with a reception and the opportunity to view a space shuttle main
engine being test fired.  The center also reports that their Early Education
Monday program was presented to 163 kindergartners from five local
elementary and day care facilities, including Stennis' own.

Here's the broadcast schedule for Public Affairs events on NASA Select
TV.  Note that all events and times may change without notice, and that
all times listed are Eastern.

Tuesday, 5/14/91
    10:00 am    Begin coverage for NOAA-D launch, from Vandenberg Air
          Force Base.  Launch is set for 11:52 am EDT. LIVE
    2:30 pm     STS-40 mission overview press briefing with lead flight
          director Al Pennington, from Johnson Space Center. LIVE
    3:30 pm     STS-40 astronaut crew press briefing with Bryan
      O'Connor, commander; Sid Gutierrez, pilot; Tammy Jernigan,
      Rhea Seddon and Jim Bagian, mission specialists; and Drew Gaffney
      and Millie Hughes-Fulford, payload specialists, from JSC.  LIVE

Wednesday, 5/15/91
    10:00 am    STS-40 general science and mission management overview
          press briefings with Dr. Arnauld Nicogossian, Dan Womac and Dr.
          Howard Schneider, from JSC. LIVE
    11:00 am    STS-40 metabolic investigations briefing with Dr.
      Carolyn Leach, from JSC.  LIVE
    11:30 am    STS-40 neurovestibular investigations briefing with Dr.
          Laurance Young, from JSC.  LIVE
    12:00 pm    STS-40 cardiovascular investigations briefing with Dr.
      Leon Farhi, from JSC.  LIVE
    12:30 pm    STS-40 cardiopulmonary investigations briefing with Dr.
          Harold Guy, from JSC.  LIVE
    1:15 pm     Magellan-at-Venus final status report, from Jet
      Propulsion Laboratory.  Magellan will have completed one full
      mapping cycle of the planet. LIVE
    2:00 pm     STS-40 musculoskeletal investigations briefing with Dr.
          Kenneth Baldwin, from JSC.  LIVE
    2:30 pm     STS-40 briefing on other disciplines and tests with Dr.
      Gary Jahns, from JSC.  LIVE
    3:30 pm     STS-40 Get-Away-Special cannister briefings from
      Goddard Space Flight Center. LIVE


This report is filed daily at noon, Monday through Friday.  It is a service of
NASA's Office of Public Affairs.  The contact is Charles Redmond, 202/453-8425
or CREDMOND on NASAmail.  NASA Select TV is carried on GE Satcom F2R,
transponder 13, C-Band, 72 degrees West Longitude, transponder frequency is
3960 megaHertz, audio is offset 6.8 MHz, polarization is vertical.

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

Date: 15 May 91 04:32:05 GMT
From: mintaka!ogicse!sequent!muncher.sequent.com![e-mail]
Subject: Re: Why the space station?

In article <[e-mail]> [e-mail] (Fraering Philip) writes:

>Mars will not be as easy to quantify with an Apollo-style sampling
>as the moon was. Anyway, even with HLV, the scale I just described
>would have to be assembled in space or the mission foregone.

Watch out, another solution in search of a problem is rearing
its ugly head...

Returning Martian polar samples wouldn't require any sort of assembly.
You would land a small drilling rig on the pole, bring up a nice
long thin core, take pictures of it as it came up, and chop pieces
out of it at intervals for on-site analysis or return to earth
via rendesvous and sample transfer in Martian orbit.  The lander/drilling
rig is all one piece, the orbiter is a separate peice.  There is no
benefit from assembly; forcing assembly on the mission could
severely handicap the functions.


--
Nick Szabo                [e-mail]
"If you understand something the first time you see it, you probably
knew it already.  The more bewildered you are, the more successful
the mission was." -- Ed Stone, Voyager space explorer

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

Date: 15 May 91 15:54:05 GMT
From: psuvm!esoc![e-mail]  (Thorsten Nedderhut)
Subject: Re: Shuttle launches

Think of the little Pegasus on B-52 and its altitude range. Try to compare it
with the STS and the SCA. Any questions?

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

Date: 15 May 91 23:13:45 GMT
From: agate!bionet!uwm.edu!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: New Subject--Solar Collectors/Antimatter

In article <[e-mail]> [e-mail] (Mark Gellis) writes:
>   1) Given a solar cell that will produce 10 kilowatts in Earth orbit,
>would the same cell (i.e., the same mass of finished product) produce more
>power if it was moved to Venus orbit, where it would be getting more than
>twice as much energy from sunlight? ...

Power output is proportional to available light, but there are limits.
Eventually the cell will overheat.  Exactly where trouble begins is a
function of the cell technology.  There may also be some nonlinearities
in the response at high light levels, I'm not sure.

If you're in the bulk solar power business, it is *probably* better to use
mirrors and turbogenerators.  Mirrors are lighter and easier to make in
large areas than solar cells, and turbogenerators have 2-3 times the
efficiency of solar cells.  They do result in more complex systems, but
in large sizes that is probably worthwhile, unless there is some special
constraint operating.

>... Could we build solar power stations, say, in Mercury orbit, where
>we would be getting more than six times the sunlight we get in Earth orbit?

If you are doing things with solar power on a large scale, doing it near
Mercury is probably better than doing it near Earth.  It will take slightly
different system designs, but it should be practical.
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: 14 May 91 14:10:44 GMT
From: aio!vf.jsc.nasa.gov![e-mail]
Subject: Re: Shuttle launches

In article <[e-mail]>, [e-mail] (DAVID F ROBINSON) writes:
> Was there ever any consideration for launching the shuttle off of the carrier
> aircraft.  It could have been carried to 40-50 kft and after it cleared the
> aircraft it could ignite its engines.  Wouldn't this have greatly reduced
> the fuel mass required?  With this scenario the shuttle also could have glided
> back in case of any engine problems.
>

The Shuttle Carrier Aircraft can carry the Shuttle. It cannot, however, carry
the Shuttle and it fully fueled External Tank!  Remember the Shuttle main
engines get ALL of their hydrogen and O2 from the tank. Even if it could carry
the External Tank, The shuttle main engines generate a combined thrust of about
450,000 pounds.  The Shuttle stack ( Shuttle, External Tank, and SRB's) weigh
about 4.6 million pounds at liftoff.  Each SRB has a little over 3.2 million
pounds of thrust.  SRB's thrust + the Shuttle main engines = about 7 million
pounds of thrust at liftoff.  Without SRB's the shuttle will go nowhere.

The Shuttle carrier aircraft (747) just cannot carry that weight.

--

Mike Kent -      Lockheed Engineering and Sciences Company at NASA JSC
        2400 NASA Rd One, Houston, TX 77058 [phone]
        [e-mail]

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

Date: 15 May 91 07:41:00 GMT
From: swrinde!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!wa4mei!ke4zv![e-mail]  (Gary Coffman)
Subject: Re: Saturn V and the ALS

In article <[e-mail]> [e-mail] (Greg Hennessy) writes:
>"You screwed up the last time, why should I trust you know?"
>
>and you say:
>
>"ALS is not the shuttle."
>
>then you lose. I don't have to prove that ALS won't work. You have to
>prove it will, at least before you expect to have large sums of money
>given to it. Since the track record so far is an expensive launch
>system that does not meet promises, it is nearly *impossible* to trust
>you again.

NASA's track record doesn't begin with the Shuttle. Most of NASA's
programs have been wildly successful. A few have not. Even for the
shuttle, most of the systems perform as planned. Bad choices, driven
primarily by budget pressure, dictated the present SRBs, tiles over
aluminum rather than titanium, and other tradeoffs that have made
the shuttle unreliable and difficult to maintain. When you look at
NASA's track record from X15 flights through Apollo, Voyager, Viking,
etc, holding the shuttle alone over their heads as representative of
their track record is unfair.

ALS is supposed to capitalize on the experience drawn from the mistakes
made with the shuttle. NASA more than anyone knows the faults of the
shuttle. NASA more than anyone doesn't want to make those same mistakes
again. NASA also has a long proven track record of things that work. They
can draw on that experience as well.

To succeed, NASA must constantly point to the shuttle, and the political
and technical decisions that made it what it is. NASA must insist that they
be allowed to build a good system, or no system at all. Whether NASA's current
leadership has this courage is the major question about the ALS or any other
system in NASA's future. The current debacle with Fred hints that they may not.
To be fair, it must be realized that the current NASA leadership took
power after major commitments to Fred were already made, including foreign
commitments. With ALS they will have a clean sheet of paper and a chance
to do it right.

Gary

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

Date: 15 May 91 15:41:54 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!menudo.uh.edu!jetson.uh.edu![e-mail]
Subject: Re: New Subject--Solar Collectors/Antimatter

In article <[e-mail]>, [e-mail]
(Mark Gellis) writes:
> My question regards the efficiency of solar collectors.  Now, obviously,
> technology will change and improve during the next few centuries, but based
> on what we know today about such solar power cells...
>
>    1) Given a solar cell that will produce 10 kilowatts in Earth orbit,
> would the same cell (i.e., the same mass of finished product) produce more
> power if it was moved to Venus orbit, where it would be getting more than
> twice as much energy from sunlight?...
>
>    2) If you can get more energy from solar cells by moving them closer
> to a star, what is the limit?...

   There are solar cells manufactured today which are designed to work with
concentrators, and can handle 100 suns (i.e., equivalent radiation at Earth,
1 sun = about 1400 W/m^2, as I recall) or more. They are more expensive than
conventional cells. So the answer is yes, as you move closer to the sun,
you can get more energy per square meter of solar array.
  However, because not all the solar flux is converted to electricity, the
rest is absorbed by the solar array as heat. The only way to get rid of this
heat is through radiation. The total heat you can get rid of this way is a
function of the array area and the maximum temp. the solar panels can take
(roughly, as Area*Temp.^4). Even if 99% of the solar flux is converted to
electricity (current cells can get 15-30%), the 1% left over as heat HAS to
be dealt with.
  Based on current technology, a solar power station close to Mercury as
you describe is feasible. But much closer than that, the thermal limit
starts to be a problem, probably long before the concentration limit becomes
an issue. This also limits how close you can bring a solar sail to the sun,
though solar sails can reflect away much of the solar flux to begin with.
  So much for the short course on radiation heat transfer. Hope this
answers your question.

Christian L. Struble                  Department of Mechanical Engineering
[e-mail]                  University of Houston
--------------------------------------------------------------------------

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

Date: 16 May 91 03:05:03 GMT
From: iggy.GW.Vitalink.COM!widener!hela![e-mail]  (Allen W. Sherzer)
Subject: Re: SPACE STATION FREEDOM WOUNDED

In article <[e-mail]> [e-mail] (Brian Yamauchi) writes:


>My question is how much of this money will actually go to space
>science and unmanned space exploration.  I'd rather have a lot of
>Mariner Mark IIs, planetary rovers, and microprobes than Freedom, but
>I'd rather have Freedom than nothing...

The real problem is that NASA is funded from the same bucket of money
as housing projects and vetrans funds. People try very hard to get on
this committee so they can shovel HUD money into their districts. From
the point of view of many of them NASA just hurts this process.

The upshot of this is that in the short run this money will go to
space science but in the long run they will eventually fall prey
to the same forces we see at work today.

The real problem of course is our socialist aerospace system. We
spend all we need to to have a good space science program AND
a good exploration program. We just don't spend our moeny very
wisely. The House action today (and if the Senate supports it)
is IMHO a step in the right direction. We need to exploit this
and turn it into an advantage.

  Allen
--
+---------------------------------------------------------------------------+
|Allen W. Sherzer |        Allen's tactics are too tricky to deal with      |
|   [e-mail]   |             -- Harel Barzilai                           |
+---------------------------------------------------------------------------+

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

End of SPACE Digest V13 #560
*******************