Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V13_5/V13_524.ZIP/V13_524

Internet Message Format | 1991-06-28 | 14KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from hogtown.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/Uc:sPXe00WBw83g05s>;
          Sat, 11 May 91 01:53:40 -0400 (EDT)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sat, 11 May 91 01:53:33 -0400 (EDT)
Subject: SPACE Digest V13 #524

SPACE Digest                                     Volume 13 : Issue 524

Today's Topics:
             Re: Why the space station?y
               Re: Saturn V and the ALS
     Re: Holding Down an Atmosphere (was Re: Teraforming Venus?)
       Re: Ethics of Terraforming (was Re: Terraforming Venus)
               Re: Saturn V and the ALS
          NASA Prediction Bulletins:  Space Shuttle
           NASA Prediction Bulletin Format
       YOUR HELP NEEDED URGENTLY TO SAVE SPACE SCIENCE!

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 May 91 04:05:26 GMT
From: stanford.edu!agate!lightning.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Why the space station?y

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>The risks may be somewhat greater, with the extra 'junk' in the are, but keep
>in mind that the Shuttle should be able to do a far better job of docking
>(granted, it's never been tried) than a Soviet unmanned spacecraft.  With
>human operators on the scene, a situation similar to the Progress incident
>could never arise; the crew in the station, the crew on the orbiter, and
>the ground controllers could all catch the situation in time and do something
>about it...one of the advantages to man in space.
>
While the pilot of the shuttle will be much better than the unmanned Progress
craft, the shuttle is also larger and less manuvrable than Progress.
Progress (and the Soyuz manned craft) have an acceleration of up to 0.615
m/s^2. The shuttle accerleates, on OMS, at 0.073 m/s^2. Also just the SIZE
of a shuttle orbiter make it awkard in close proximity of a station.

>Also, I wouldn't put a lot of trust in Soviet docking abilities; they've been
>notoriously deficient in this area for thirty years.

Over 30 years they may be deficient, but they have been very good in the
the more recient past. All docking attempts to the Mir station have been
successful (manned dockings that is). The last manned docking failure in
the soviet program was Soyuz-T 8 in April 1983. Since then they have made
17 successful dockings. However, they do not always dock on the first
pass.

                           Frank Crary
                           UC Berkeley

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

Date: 7 May 91 22:27:30 GMT
From: orca!bambam![e-mail]  (Bob Pendleton)
Subject: Re: Saturn V and the ALS

In article <[e-mail]>, [e-mail] (Dave Smith) writes:
> In article <[e-mail]> [e-mail] (Paul Blase) writes:
> >Several things that I think that most people are missing about the ALS.
> >
> >The ALS is NOT an attempt to build a latest, state-of-the art,
> >Lamborghini-class launch vehicle.  Rather, it is a "Ford Pickup" class
> >hauler.  The end goal is minimization of launch costs, NOT maximization
> >of performance.  To this end:
>
> No, nobody is missing anything.  You're just on different wavelengths.
> You are saying the NASA says the ALS will be a "pick-em-up truck."  Because
> it's built to perform as a pick-em-up truck it will be cheap.
>
> What everyone else is saying is "The Shuttle was going to be a pick-em-up
> truck.  Why is ALS different?"  The only answer I've seen you give to date
> is "NASA says so."


There is one reason to believe that ALS will be close to what it is
claimed to be: The Air Force says so.

There is some big general somewhere, along with a few little generals,
a bunch of colonels, majors, captains, ... Whose next promotion
depends on ALS being exactly what they say it will be. The Air Force
works on an "up or out" system. If you don't move up in rank you wind
up out of the Air Force. So there is strong motivation to do what you
said you would do.

ALS is being designed so that all launch pad servicing can be done
without a service tower. It is being designed that way because a
general said to do it that way. He said it because service towers are
expensive and using them leads to expensive prelaunch operations.

The U.S Air Force are the people who brought you the Atlas and Titan
boosters, the Minute Man I, II, and III, and the Peacekeeper missiles.

I won't claim that the Air Force doesn't make mistakes. Their cost
over runs are legendary. But they have produced a series of
operational rocket based systems. And they have operated those systems
since before there WAS an USAF.

Of course NASA can still screw it up.

--
              Bob Pendleton, speaking only for myself.
   [e-mail] or decwrl!esunix!bpendlet or hellgate!esunix!bpendlet

                         Tools, not rules.

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

Date: 6 May 91 13:59:08 GMT
From: hpfcso![e-mail]  (Mark Luce)
Subject: Re: Holding Down an Atmosphere (was Re: Teraforming Venus?)

/ hpfcso:sci.space / [e-mail] (Jonathan Monsarrat) /  7:21 pm  May  3, 1991 /
Ganymede has about 1/7 of the Earth's gravity even though it's big.
This is because it is mostly ice. If a lot of water vapor or
atmosphere of some sort were created by
   a. melting a lot of ice
   b. pummeling it with ice comets

does anyone know how long it would take for the atmosphere to bleed off?
How much gravity does a body need to have an atmosphere anyway?

   > Ganymede is evidently large enough to have an atmosphere, since Titan
   > has about the same surface gravity and has an atmosphere about half
   > again as dense as Earth's. My question would be, why does Titan have
   > such a thick atmosphere while Ganymede does not?

And if it were a satellite (Ganymede), would its focus (Jupiter) steal
the atmosphere away anyway?

Much appreciation for any insight into this. Thank you!

-Jon Monsarrat
 [e-mail]
 [e-mail]
----------

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

Date: 8 May 91 02:38:36 GMT
From: VAX1.CC.UAKRON.EDU!mcs.kent.edu!usenet.ins.cwru.edu!agate!headcrash.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Ethics of Terraforming (was Re: Terraforming Venus)

In article <[e-mail]> [e-mail] (Ken Sheppardson) writes:
>  Is there anyone else out there who questions the ethics of tampering
>  with other planets (with or without the presence of life) to make them
>  more 'earthlike'? I'm all for non-intrusive exploration and the
>  construction of free-floating stations/colonies, but given our history
>  of 'Manifest Destiny', rain forest destruction, ozone depletion, strip
>  mining, etc, I feel like we should take a hands off approach to space.

In fact Chirs McKay of NASA/Ames has written several papers on the ethics
of terraforming Mars. One thing he points out is that, by making a dead
planet livable (though not necessarily like Earth), we would INCREASE
the number of environments for living creatures (exactly the reverse of
the destruction of the rain forests.)
Also, there is reason to believe that, although Mars is now a dead planet,
it once had a thick atmosphere and a warmer climate. Potentially, life
could have evolved on Mars, and died as the climate changed. If this is
the case, terraforming Mars would RESTORE a previously destroied climate.

By the way, you put 'Manifest Destiny' in a class with rain forest destruction
ozone depletion, strip mining, etc.. While there were many unfortunate
and very negative effects of the United States expansion into the west, I
do not see the attitude of "manifest destiny" as their cause. As far as
I understand it, "manafest destiny" was simply the belief that the growth
of the US was clearly and obviously what was going to happen, and where the
future would be. I believe this same attitude could be applied to space,
and would not necessarily cause problems.

                     Frank Crary
                     UC Berkeley

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

Date: 8 May 91 01:58:49 GMT
From: haven.umd.edu!uvaarpa!murdoch!astsun9.astro.Virginia.EDU![e-mail]  (Greg Hennessy)
Subject: Re: Saturn V and the ALS

In article <[e-mail]>
[e-mail] (/dev/null) writes:
#It not the Shuttle.  Why Should it be the same?

The problem is, and I know that I am being overly harsh on the shuttle
on this, but Joe Congresscritter, or even Joe Average Public can just
say:

"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.

You have to earn the trust of those who control the money. So far ALS
has not.

--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 28 Apr 91 23:55:16 GMT
From: udecc.engr.udayton.edu!blackbird.afit.af.mil![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletins:  Space Shuttle


The most current orbital elements from the NASA Prediction Bulletins are
carried on the Celestial BBS, [phone], and are updated several times
weekly.  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current
elements for the current shuttle mission are provided below.  The Celestial
BBS may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data
bits, 1 stop bit, no parity.

STS 39
1 21242U 91 31  A 91118.60338562  .00193162  23739-4  25599-3 0    26
2 21242  56.9897 288.8514 0009153 256.9690 102.8903 16.06278845    20
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 29 Apr 91 00:19:22 GMT
From: udecc.engr.udayton.edu!blackbird.afit.af.mil![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletin Format


As a service to the satellite user community, the following description
of the NASA Prediction Bulletin's two-line orbital element set format is
uploaded to sci.space on a monthly basis.  The most current orbital elements
from the NASA Prediction Bulletins are carried on the Celestial BBS, (513)
427-0674, and are updated several times weekly.  Documentation and tracking
software are also available on this system.  The Celestial BBS may be
accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop
bit, no parity.

==============================================================================

Data for each satellite consists of three lines in the following format:

AAAAAAAAAAA
1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN

Line 1 is a eleven-character name.

Lines 2 and 3 are the standard Two-Line Orbital Element Set Format identical
to that used by NASA and NORAD.  The format description is:

Line 2
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 10-11     International Designator (Last two digits of launch year)
 12-14     International Designator (Launch number of the year)
 15-17     International Designator (Piece of launch)
 19-20     Epoch Year (Last two digits of year)
 21-32     Epoch (Julian Day and fractional portion of the day)
 34-43     First Time Derivative of the Mean Motion
        or Ballistic Coefficient (Depending on ephemeris type)
 45-52     Second Time Derivative of Mean Motion (decimal point assumed;
           blank if N/A)
 54-61     BSTAR drag term if GP4 general perturbation theory was used.
           Otherwise, radiation pressure coefficient.  (Decimal point assumed)
 63-63     Ephemeris type
 65-68     Element number
 69-69     Check Sum (Modulo 10)
           (Letters, blanks, periods = 0; minus sign = 1; plus sign = 2)

Line 3
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 09-16     Inclination [Degrees]
 18-25     Right Ascension of the Ascending Node [Degrees]
 27-33     Eccentricity (decimal point assumed)
 35-42     Argument of Perigee [Degrees]
 44-51     Mean Anomaly [Degrees]
 53-63     Mean Motion [Revs per day]
 64-68     Revolution number at epoch [Revs]
 69-69     Check Sum (Modulo 10)

All other columns are blank or fixed.

Example:

NOAA 6
1 11416U          86 50.28438588 0.00000140           67960-4 0  5293
2 11416  98.5105  69.3305 0012788  63.2828 296.9658 14.24899292346978

Note that the International Designator fields are usually blank, as issued in
the NASA Prediction Bulletins.

--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 8 May 91 18:26:45 GMT
From: snorkelwacker.mit.edu!hsdndev!frooz!cfashap![e-mail]  (Philip Pinto)
Subject: YOUR HELP NEEDED URGENTLY TO SAVE SPACE SCIENCE!

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

End of SPACE Digest V13 #524
*******************