Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_1/V11_167.TXT

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Date: Wed, 21 Mar 90 02:54:18 -0500 (EST)
Subject: SPACE Digest V11 #167

SPACE Digest                                     Volume 11 : Issue 167

Today's Topics:
             Re: Shuttle Escapes
               Re: Geostationary orbit
           Another SR-71 comes to NASA Ames-Dryden
         Re: Another SR-71 comes to NASA Ames-Dryden
     Re: Coilgun on a 747 - supplies to orbit at $20/lb?
           Payload Status for 03/20/90 (Forwarded)
             Re: Intelsat / Titan failure
        Re: What was Challenger really up to?
     Re: Coilgun on a 747 - supplies to orbit at $20/lb?
----------------------------------------------------------------------

Date: 20 Mar 90 21:25:32 GMT
From: concertina![e-mail]  (Steve Hix)
Subject: Re: Shuttle Escapes

In article <[e-mail]>, [e-mail] (A J Cunningham) writes:
> In article <[e-mail]> [e-mail] (Mary Shafer (OFV)) writes:
> #nobody is forced to fly in fighters or bombers or airliners.  We're
>
>     Unless of course they are unlucky enough to be drafted. (No :-))

Except during wartime, combat aircrew are generally volunteer.  You have
to figure ways to weed out the excess, actually.  (Getting enough to
re-up can be a problem, what with airlines paying better and all.)

Airline crews don't seem to be affected much by the draft, now, do they?

(No :-))

------------
"...Then anyone who leaves behind him a written manual, and likewise
anyone who receives it, in the belief that such writing will be clear
and certain, must be exceedingly simple-minded..."   Plato, _Phaedrus_

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

Date: 20 Mar 90 20:58:33 GMT
From: zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu![e-mail]  (Johnny Zweig)
Subject: Re: Geostationary orbit

[e-mail] (Christopher Schaller) writes:

>Quick question!
>How high does a satellite have to be to atain  geostationary orbit

A satellite on the ground has a very nice geostationary orbit.

>geosynchrous orbit?

About 22,000 miles.

>                  Thanks
>                   Chris.

-Johnny

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

Date: 19 Mar 90 19:18:00 GMT
From: skipper![e-mail]  (Mary Shafer (OFV))
Subject: Another SR-71 comes to NASA Ames-Dryden


Monday, 19 March

0900  (Mary) Don, when's the SR-71 flyby gonna be?
      (Don)  About 1030

0945  (Mary) Don, still on for 1030?
      (Don)  Yeah, the SR-71 will call the tower, they'll call
             us, and we'll make an announcement.

1020  (PA)   The SR-71 flyby will be delayed at least 20 minutes.
             Please listen for further information.

1030  (??)   ROOOOAAAARRRRR!

103001 (Mary and about 20 others) OH SHIT

103002       Sound of many running feet

Most of us arrived on the roof or ramp just in time to see the SR-71
flying north of Dryden.  It turned south over the mines, put the gear
down, and then turned west on final to runway 22.  We were all cursing
the pilot for doing only one flyby, cursing the system for not letting
us know, and panting.

The plane did a beautiful landing but no chute.  Could it be?  Yes, he's
on the go, look at the nose come up.  All right, bring it back over.

But instead of turning right, he turned left, and went back around the
pattern.  Oh look, he's on base.  Is the gear down?  I don't think so.
He's not turning tight enough to make the runway.  HE'S COMING BACK!

And back he did indeed come.  Straight at us, no more than 100 ft AGL.
Look at the smoke.  Come on, burner, burner, burner!  Burner light!
OH, WOW.  Did you feel that?  My whole body is resonating.  Look at
the burners.  OH, WOW.  Is he going to do another one?

Nope.  Gear down, back on final, touch down, drogue chute.  Oh, rats.

And everybody troops back into the building on this beautiful spring
day, exhilerated by the flyby.

(Overheard on the stairs: An SR-71 flyby is like sex; when it's good
it's very, very good and when it's bad, it's still pretty good!)

--

Mary Shafer  [e-mail] or ames!skipper.dfrf.nasa.gov!shafer
         NASA Ames Dryden Flight Research Facility, Edwards, CA
                   Of course I don't speak for NASA

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

Date: 19 Mar 90 20:26:44 GMT
From: skipper![e-mail]  (Mary Shafer (OFV))
Subject: Re: Another SR-71 comes to NASA Ames-Dryden

In article <[e-mail]> [e-mail] (Mary Shafer (OFV)) writes:

>Monday, 19 March

>0900  (Mary) Don, when's the SR-71 flyby gonna be?
>      (Don)  About 1030

>0945  (Mary) Don, still on for 1030?
>      (Don)  Yeah, the SR-71 will call the tower, they'll call
>             us, and we'll make an announcement.

>1020  (PA)   The SR-71 flyby will be delayed at least 20 minutes.
>             Please listen for further information.

>1030  (??)   ROOOOAAAARRRRR!

>103001 (Mary and about 20 others) OH SHIT

I'm told it should be 200, not 20.

>103002       Sound of many running feet

 1031  (PA)   The SR-71 has arrived.

>And back he did indeed come.  Straight at us, no more than 100 ft AGL.
>Look at the smoke.  Come on, burner, burner, burner!  Burner light!
>OH, WOW.  Did you feel that?  My whole body is resonating.  Look at
>the burners.  OH, WOW.  Is he going to do another one?

When the SR-71 was directly overhead, I could see only one burner
cone, from the right burner.  After he passed, I looked up the
tailpipe and saw the orange flame in both burners.  I thought I just
didn't see the left cone--sun angle or something.  After discussing it
with some other engineers, we've decided that he probably didn't get a
good light on the left burner.  I'm told, however, that this flyby was
louder than that of the previous SR-71, which had both burners lit.

Anyway, you should have been here.

--

Mary Shafer  [e-mail] or ames!skipper.dfrf.nasa.gov!shafer
         NASA Ames Dryden Flight Research Facility, Edwards, CA
                   Of course I don't speak for NASA

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

Date: 19 Mar 90 20:43:43 GMT
From: sam.cs.cmu.edu![e-mail]  (Vincent Cate)
Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb?


Walt Leipold:
>In all this discussion of recoil problems and the need to keep flying,
>has anyone considered shooting the coilgun out the _rear_ of the 747?
>If you're really launching significant masses (> 20 kg/min?), you could
>probably keep the 747 in the air using "mass driver" propulsion. (Now,
>all we've gotta do is find a power source for that sucker...)

The recoil is not a problem.  The airplane engines are outputting
about as much energy as the generators used to power the gun.
Momentum is mass times velocity.  Kinetic energy is 1/2*mass*velocity^2.
The gun is putting so much energy into getting a really high velocity
that the momentum is very small compared to what the engines get by
pushing air back at a more reasonable speed.

As for powering the sucker, the thing I am worried about is storing
the 1,000 kw-hours such that you can deliver it in a millisecond or so.
A gas turbine or two will give you a 20,000 kw power source you can
put on a 747.

I don't think we will be able to use "mass driver propulsion".  With
20,000 kw we are able to give a push enough to add about 1 MPH
to a 747 only about every 3 minutes (50 lb projectile).  This is not
going to keep it in the air.   If a 747 were to glide for 1 hour it
would loose more than 20 MPH.  :-)

Now if you had a plane that was getting power from the ground using
microwaves and was launched from a large plane such that it did not need
any engines etc, maybe, someday.  It would be nice.

   -- Vince

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

Date: 20 Mar 90 16:01:34 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 03/20/90 (Forwarded)


    Daily Status/KSC Payload Management and Operations 03-20-90.


    -STS-31R HST (at VPF) -

    HST closeouts and VPHD alignment were worked yesterday and
    will continue today.  Also today, payload support will be
    provided for the terminal countdown demonstration test.

    -STS-32R SYNCOM/LDEF (at SAEF-2) -

    LDEF deintegration continues.


    Sts-35 ASTRO-1/BBXRT (at O&C) -

    Yesterday the payload was moved from the O&C to the OPF.
    Today the payload will be installed into the orbiter on
    first shift and electrical connections will start on second
    shift.

    -STS-40 SLS-1 (at O&C) -

    The power up portions of systems test and ECS systems test
    were completed yesterday.  Today systems test post
    operations and experiment train disconnects from level IV
    and preps for transfer to level III/II will be active.  Fire
    suppression bottle installation will also be worked today
    during second shift.

    -STS-42 IML (at O&C) -

    Staging activities on racks 3, 7, 8, and 11 were worked
    yesterday.  Staging activities on racks 4, 7, 10, and 12 are
    scheduled for today.

    -STS-45 Atlas-1 (at O&C) -

    Yesterday installation of the pallet joint kit on frame 1
    was active.  No work is scheduled for today.

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

Date: 20 Mar 90 17:33:52 GMT
From: zaphod.mps.ohio-state.edu!usc!cs.utexas.edu!wuarchive!rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: Intelsat / Titan failure


About [e-mail] (will martin's) questions:

As far as I know, the Intelsat 6 satellite is separated from its
perigee stage, which is left on the booster. The perigee stage is the
stage which puts it into the geostationary orbit (perigee 200 miles;
apogee 22,000 or thereabouts miles).

I do not know if the upper stage was controllable to the extent that it
could be used to circularize the orbit, or whether or not a separate
apogee 'kick-stage' was to be used. Possibly the satellite has onboard
thrusters for this purpose.

Apparently, if the 'kick motor'/onboard thrusters (whichever it has) aren't
fired soon, the satellite will reenter within two weeks.

Read a couple of the NASA payload bulletins about the long lead times for
the payloads.

The shuttle has a very long lead time for installing the payload and
launching; I believe the optimistic pre-Challenger turnaround time for
an orbiter was 2 months. Nasa cannot, and private enterprise cannot, launch
a shuttle or cludge together a shuttle payload faster than that. It is an
inherent bug in the shuttle design giving it such long payload loading
lead times and launch lead times. Fred McCall will probrably say that this
is not a bug, it's a feature. ;-) In short, the vehicle itself is incapable
of it.

Besides, the Hubble Space Telescope cost somewhere around $2 billion and is
seven years late. It has priority. Or should.

About your point about whether gov't should rescue a private satellite:
Intelsat is a consortium of private companies and governments, including
the United States. Intelsat 6, therefore, is a quasi-public/quasi-private
satellite.

I doubt anyone could rescue it in the 2 weeks it might have left.

If they can stabilize the orbit, however, maybe something could be done,
such as public or private efforts.

Philip Fraering

[e-mail]

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

Date: 21 Mar 90 01:34:26 GMT
From: comphy![e-mail]  (Douglas Buettner)
Subject: Re: What was Challenger really up to?

In article <[e-mail]> [e-mail] (Arnold G. Gill) writes:
>......
>     The real cause of the Challenger accident was not O-ring failure as we
>are all meant to believe, but rather due to an accidental discharge of the
>military laser being carried (illegally) up into orbit, which blasted through
>the shuttle and exploded the fuel tanks.  Proof of this is supposed to come
>from the fact that there was a military laser expert on board the shuttle, who
>would have no purpose on the mission if no laser was included in the manifesto.
>Also, much of the cockpit recorder tape was never released and was actually
>erased, as it contained comments pertaining to the military cargo that was
>being launched.  In addition, the fact that the cabin of the Challenger was
>not located for a month, even though it was in the shallowest water around.
>This was done to make sure that everybody on board was actually dead.  The
>O-rings were eventually blamed as part of the coverup.
>
A good book to read about the Challenger Disaster that will help set your
mind at ease would be ..."What do you care What other people think..." which
is in paperback and was written by the late Dr. Richard P. Feynman, a nobel prize
winner.  Dr. Feynman was on the Presidential Commission which investigated the
disaster.  I believe you will find it to be quite informative.

******************************************************************************************
*                                   |     STANDARD DISCLAIMER                            *
*     Douglas J. Buettner           |                                                    *
*                                   |              STANDARD DISCLAIMER                   *
*  Graduate Research Assistant      |                                                    *
*   Oregon State University/        |                       STANDARD DISCLAIMER          *
*  Jet Propulsion Laboratory        |                                                    *
******************************************************************************************

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

Date: 19 Mar 90 18:58:20 GMT
From: sumax!ole![e-mail]  (Mike Upton)
Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb?

Just to add a few cents:

1) 747-400 briefly held maximum takeoff weight record of ~1E6 lbs.
this weight is limited by the ability of the breaks and engines to stop
the plane during a takeoff abort.
most of this weight is fuel.
(the record is currently held by the soviet AN225, their shuttle carring plane
at 1.2 million lbs. AN225 is 250ft long)
both items from AvLeak.

2) US airforce has C-130 based 105mm howitzer gunships. The cannon
is bolted into the side of the plane. What is the weight and muzzle velocity
of a 105 shell?
They had to provide special strengthening for the airframe.

3) The service ceiling for a 747 is much heigher than 40000ft. 36K ft is
simply the most economical cruise altitude. The pegasus launch will be from
a B52 at ?48000 ft?.


so, forget this sliding gun stuff, just bolt a 50m railgun to
the top of the airframe.

acceleration for 50m gun with 6.5 km/sec muzzle velocity is 43112 g's.
so thats 2.15 million lbs force for a 50lb mass.
2e6 lbs may not be that bad if its distributed
over the airframe. The plane has to hold itself up when on the
ground, and thats 1e6 lbs.

if the empty plane weighed 200,000 lb it would be
slowed by 6.5 * 50/200000 = 1.62 m/sec, not exactly stall speed.

if 2e6 lbs is too much, we could use a 1 meter shock absorber.

One additional thing to worry about is the effect of an off axis force of
2e6 lbs. but it is so short lived that it should not cause much problem.
--
Michael Upton@Seattle Silicon (uucp: ...uw-beaver!sumax!quick!ole!upton)
/*           Semi-conducting our business since 1983        */

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

End of SPACE Digest V11 #167
*******************