Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V13_3/V13_367.ZIP/V13_367

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Subject: SPACE Digest V13 #367

SPACE Digest                                     Volume 13 : Issue 367

Today's Topics:
          NASA Prediction Bulletins:  Space Shuttle
             Re: I want to go to orbit...
          Underground Nuclear Test in Nevada
            News from Spaceflight
        Re: comsat cancellations and lawsuits
            SPACE Digest V13 #356
            Space Shuttle on Paragon Cable
                Re: Mt. Venus
           NEP to Mars!?!? - a thesis topic

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: 6 Apr 91 00:02:54 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 37
1 21224U 91 27 A  91 95.65050502  .00000248  00000-0  32191-5 0    16
2 21224  28.4682 238.4333 0008760 266.0250  93.9346 15.37932365    10
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 5 Apr 91 15:54:12 GMT
From: edsews![e-mail]  (Matt Clairday)
Subject: Re: I want to go to orbit...

In article <[e-mail]>, [e-mail] (Mark SOKOLOWSKI) writes:
>
>     What are the steps in order to build a reliable space-shuttle like
> spaceship in order to send myself to orbit for the summer holidays?
> I'm thinking about a 20-30 ton rocket with a 900 kg payload made up of
> a car sized hypersonic glidder, fitted with 3 rocket engines. There will
> be 2 boosters of about 10 tons each, and a main liquid hydrogen-oxygen
> tank of about 10 tons too. I have a Chalet near a lake with some forest

  Mark, this shouldn't be any problem.  Just see your local nasa surplus
  dealer for the relevant parts.  A bright guy like you should have
  no trouble deducing the assembly instuctions from sifting through
  relevant space shuttle articles of the period 1981-1990.


> I guess I'll break the canadian law forbidding to send rocket of more
> than 650 gramms (20 oz) in the air... but I'll land somewhere else.
> Thanks in advance for any advice.
>

  I would suggest using stealth technology to hide your project from
  the canadian govt. officials.  good luck, and happy holidays.


--
Matt Clairday
EDS Technical Infrastructure Services
ARPA: [e-mail]
UUCP: {uunet|sun|sharkey}!edsews!clairday

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

Date: 5 Apr 91 14:35:19 GMT
From: agate!bionet!uwm.edu!rpi!news-server.csri.toronto.edu!news-server.ecf!ecf![e-mail]  (MURTY Hema Sandhyarani)
Subject: Underground Nuclear Test in Nevada


    Yesterday there was another underground nuclear test in
    Nevada.  Why are we allowing this to continue?

    I am sure that if all the readers of sci.space got
    together and denounces such tests by countries of
    the world, they would have to stop.

    And, yes, I would like to hear arguments that any
    might have in favor of these tests.  What do they
    accomplish in terms of science?  They seem more
    like muscle-flexing to me.

Hema Murty
Research Associate
National Research Council of Canada
[e-mail]

Disclaimer:  These opinions are my own and do not reflect those
of the National Research Council of Canada

Discla

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

Date: 5 Apr 91 15:46:37 GMT
From: skipper![e-mail]  (Mary Shafer)
Subject: News from Spaceflight

In article <[e-mail]>
[e-mail] (Henry Spencer) writes:

   March issue of Spaceflight mentions that astronaut William F. Fisher has
   left NASA to return to medical practice.  No big surprise, on thinking
   about it:  he was co-chair of the group that reported the bad news about
   EVA requirements for Fred, which probably killed his chances of future
   flight assignments.

I always thought he just joined up to keep up with his wife, Anna.
She was originally picked as a Mission Specialist and he moved to
Houston with her and worked as an emergency room physician (there's
probably a more dramatic phrase, like trauma specialist).  He was
picked up as a mission specialist on the next round, some time later.

I also wondered if the other astronauts liked having a pair of MDs on
_their_ side, not management's.  Military flight surgeons struggle
with this conflict of interest, for example, and usually end up more
on the pilot's side.  I believe that corporate flight surgeons tend to
stay in the management camp better.  (Maybe it's who's got the best
back/right seats?)
--
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: 5 Apr 91 16:28:18 GMT
From: usc!zaphod.mps.ohio-state.edu!rpi!uupsi!pbs.org![e-mail]
Subject: Re: comsat cancellations and lawsuits

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:

> Agreed that the US is lawsuit-happy, for which government tax and financial
> policy bears no small share of the blame... but Hughes got a seriously raw
> deal on this one, and has every right to be ticked off.
> --
Considering passed performances and some questionable over charging, I'm
not sure that Hughes or any other aerospace firm has a "right" to be ticked
off.  Call it poetic justice.  This law suit, no matter who wins, is going to
cost the U.S. taxpayer.  Since Henry is Canadian he doesn't have to worry,
though. :-)

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

Date: Fri, 5 Apr 91 13:48:57 EST
From: [e-mail] (John Sahr)
Subject: SPACE Digest V13 #356


> Assuming an escape velocity of 11km/s at the top of the atmosphere,
> and assume a 200km thick atmosphere. Use friction .15 to estimate
> decreasing density with altitude, and assume a 45 degree shot.

200 km is a bit much; satellite passes have dipped as low as 115 km
without falling down.  E-region sounding rockets must deploy their
relatively fragile booms below the E-region, and do so while still
supersonic, at approximately 80 km.

Given that the atmospheric density falls off exponentially, then at
constant speed, the aerodynamic friction will fall off exponentially
as well.  Thus, since the "scale height" (e-folding length) of the
atmosphere is about 10 km, the effective depth is about 10 km as
well...  at 10 km altitude, 70% of _all_ the atmosphere is below you.
Surprising, but true.

The reason that "max Q" happens at fairly high altitude for the
shuttle is that it is moving at low speed in the lower atmosphere.  At
high Reynold's number, the friction scales as approximately rho v^3,
where rho is the mass density of the fluid, and v is the velocity
through it.  At low altitudes, rho is large, but (shuttle) v is quite
small.

Some sounding rockets must be launched nearly vertically in order to
get out of the thick atmosphere as quickly as possible---the engines
will push the rockets to high speeds through the thicker air, but it
may tear the fins off, which will ruin their spin stabilization and
otherwise unbalance them.  Sounding rocket fins are heavy, and are
made of _very_ strong material for this reason.

-john

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

X-Ns-Transport-Id: 0000AA002C4644602BBA
Date:     Fri, 5 Apr 1991 16:23:14 PST
Sender: [e-mail]
From: "Craig Anderson <Anderson:El Segundo>"@xerox.com
Subject: Space Shuttle on Paragon Cable
To: [e-mail], [e-mail],
        [e-mail], [e-mail],
        [e-mail], [e-mail]
Cc: [e-mail]
Reply-To: [e-mail]


Paragon Cable is again broadcasting the NASA Select network, this time on
channel 59.  Paragon Cable serves Hawthorne, Gardena, Torrance, El Segundo,
Lawndale, and parts of Redondo Beach, CA.

NASA Select began continuous coverage this morning at 4:30 AM ET with the
launch of STS-37 Atlantis occuring at 9:22 AM ET.  Following is a schedule of
STS-37 activities to be carried on NASA Select.  Scheduled times are subject to
change.  Call NASA Select at [phone] to hear recorded program information
and updated air times. ALL TIMES ARE EASTERN TIME.

Fri., 4-5-91
12:36 PM ET Live payload bay views
12:45 PM ET Live JSC Flight Director briefing
 2:38 PM ET Live payload bay views and robot arm checkout
 3:48 PM ET Live Gamma Ray Observatory checkout
 4:20 PM ET KSC playback of STS-37 launch video (all camera locations)
 7:00 PM ET JSC playback of STS-37 flight day 1, flight crew, and payload bay
activity
 7:30 PM ET KSC playback of STS-37 launch film footage (including slow motion)
 8:45 PM ET Live JSC Flight Director Change of Shift briefing

Sat., 4-6-91
 7:45 AM ET Live JSC Flight Director Change of Shift briefing
 7:45 AM ET Live concurrent ham radio operations from Atlantis
11:18 AM ET Live crew checkout of spacesuits
12:45 PM ET Live JSC Flight Director briefing
 1:55 PM ET Playback of shuttle views of Central & South America

Sun., 4-7-91
 6:45 AM ET Live JSC Flight Director Change of Shift briefing
 6:48 AM ET Begin live coverage of Gamma Ray Observatory deployment (process
begins at 7:20 AM and continues until 1:00 PM)

Mon., 4-8-91
 8:28 AM ET Live coverage of EVA development experiment coverage of
spacewalking astronauts

There will also be a lot of unscheduled live video from Atlantis at all times.
Landing is scheduled for Wed., 4-10-91 at Edwards AFB, CA.

"NASA Select" is NASA's very own television network.  All non-classified
launches are carried live, as well as other important events, such as press
conferences, press briefings, and teleconferences.  During the shuttle missions
there is complete round-the-clock mission coverage of flight activities,
beginning several hours before launch and lasting several hours after
touchdown.  NASA Select carries video that you will never see on the networks,
such as unedited launch video from all the engineering cameras as well as live
downlink TV from the shuttle itself and full coverage of Mission Control.
Non-shuttle launches are also carried live, such as Atlas and Delta launches
from Kennedy Space Center and Vandenberg Air Force Base.  You can call NASA
Select at [phone] to hear recorded program information and air times.

John Webber of Paragon Cable, [phone], has been the main person
responsible for getting this on the air, but he needs to convince his manager
that there is enough interest out there for it to continue.  John would like as
many people as possible to write him a letter asking for this service to
continue.  He will hand deliver these letters to his manager.

PLEASE write him if you are interested in this service.  Send your letters to
John Webber, Paragon Cable, 3350 Civic Center Drive, Torrance, CA 90503.  Thank
you.

Craig

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

Date: 5 Apr 91 15:32:28 GMT
From: usc!rpi!news-server.csri.toronto.edu!helios.physics.utoronto.ca!aurora.physics.utoronto.ca![e-mail]  (Christopher Neufeld)
Subject: Re: Mt. Venus

In article <[e-mail]> [e-mail] (Paul Schinder) writes:
>In article <[e-mail]> [e-mail] (Christopher Neufeld) writes:
>>   So, putting my hand to these equations, using the adiabatic model for
>>atmosphes, as recommended in an undergraduate course I once took, I get,
>>using P0 = 9E+6 Pa, T0 = 800K, g = 8.87 m/s^2, molecular weight = 44,
>>gamma = 7/5:
>>P(h=914m) = 85 atm
>>T(h=914m) = 787K
>>
>>   Something looks funny about this, but the equation does say that the
>>atmosphere ought essentially to disappear at 50km altitude, and that
>>doesn't seem completely unreasonable. Maybe somebody could check my
>>numbers, just to be on the safe side.
>
>The numbers are:
>
>        at 0 km:  P = 93.0 bar, T = 731K
>    at 10 km: P = 47.5 bar, T = 650K
>    at 50 km: P = 0.97 bar, T = 346K
>
   Thanks Paul. Putting the 0km values into the adiabatic model gives:
at 10 km: P = 45.8 bar, T = 597 K
at 50 km: P = 0.015 bar, T = 60 K
So, the adiabatic model seems not so bad at low altitudes, but boy, does
it fail as you go higher! For that matter, above 54.5 km the adiabatic
model gleefully returns an imaginary pressure and complex temperature.
   Getting back to the original question, I answered the question for
3000 feet, when the question asked for 30000 feet. At that height, the
adiabatic model gives:
P = 48.9 bar  T = 608 K    h = 9.1 km

>Paul J. Schinder
>Department of Astronomy, Cornell University
>[e-mail]


--
 Christopher Neufeld....Just a graduate student  | Flash: morning star seen
 [e-mail]    Ad astra! | in evening! Baffled
 cneufeld@{pnet91,pro-cco}.cts.com               | astronomers: "could mean
 "Don't edit reality for the sake of simplicity" | second coming of Elvis!"

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

Date: 5 Apr 91 07:20:25 GMT
From: att!emory!ducvax.auburn.edu![e-mail]
Subject: NEP to Mars!?!? - a thesis topic


I'm an Aerospace engineering graduate student starting work on his thesis,
and am looking for some easy information (trying to avoid legwork :-)....

I am designing a Nuclear Eectric Propulsion spacecraft with a twist for a
Mars cargo mission.  The twist is the use of a lightweight radiator such as
a liquid droplet radiator or rolling belt radiator to drastically cut the
weight of the spacecraft.  The primary thrust of my work is going to be the
choice and design of the radiator, but I need to integrate it into a
spacecraft of my own (admittedly rough cut) design.

What I wish to know at this point is nearly anything in the "Backround"
section listed below.  However, the primary information, or rather, sources
thereof, in that section would be 1.B., E.2., and any specific papers that
would qualify for E.1.

I am posting the entire outline so that those of you who are interested can
check it out see if anything catches your eye or if might think you know of
something of special interest in other areas.  Thanks....

                     My Tentative Thesis Outline (4/2/91)

I. Background
      A. Inevitability of deep space missions/exploration
      B. Problems/parameters of deep space missions
            1. Mission length
                  a. Life Support
                  b. Deep Space Base Support
                  c. Fuel availability or lack thereof
      C. Need for reduction in time and/or fuel required.
      D. Available/projected solutions to these problems
            1. Nuclear thermal rockets
                  a. advantages
                  b. limitations
            2. Nuclear electric rockets
                  a. advantages
                  b. limitations
            3. Other
                  a. advantages
                  b. limitations
      E. Mars as example
            1. Why? due to database available for comparison
            2. Any specific Mars problems/advantages over other deep space
               scenarios?
      F. My mission choice as part of a solution to the deep space problems
         specific to Mars (NEP for cargo missions, advanced fuel resupply?)

II. NEP Familiarization
      A. Overview, listing of components
            1. Electric Thrusters
            2. Powerplant
            3. Radiators
      B. ???How these components drive the design of the vehicle???

III. Radiators (the meat of the thing)
      A. Conventional
      B. Alternatives
      C. My choice
            1. Reasoning behind choice
                  a. efficiencies and trade-offs
                  b. technology issues

IV. Design of Spacecraft
      A. Reiteration of mission objectives and therefore possible payloads
      B. Thruster/fuel choice
            1. reasoning (result of expected mission profile)
                  a. available thrust
                  b. technology issues
      C. Reactor parameters (result of thruster choice)
      D. Radiator parameters (result of reactor parameters)
      E. System integration into a single spacecraft

V. Mission analysis
      A. review of the orbital mechanics involved
            1. impulsive thrust (ballistic trajectories)
            2. constant low thrust
      B. computational methods
      C. results

VI. Conclusion
      A. Good or bad
      B. Reason
      C. Cheerleading


==========================================================================
              Disclaimer?  I don't need no stinkin' disclaimer!

                           Brendan C. Bayne
                        [e-mail]
                        [e-mail]

                           Making it happen!
==========================================================================

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

End of SPACE Digest V13 #367
*******************