Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_2/V11_291.TXT

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Subject: SPACE Digest V11 #291

SPACE Digest                                     Volume 11 : Issue 291

Today's Topics:
          Re: Pegasus launch from Valkyrie  (or ...
             Re: B70/B58 - Pegasus launch
           Re: Last year's BIG asteroid...
                [HELP] Insult
            Re: Pegasus launch techniques
               Re: voyager images on cd
              Re: space tomatoes
                 Re: Needles
           Re: Questions about the Voyagers
         Re: Apollo 13, STS-1, Vostok 1 anniversaries
           Re: Winch Launch as first stage.
            Re: Abundance of stars
     Very long wavelength antenna (was Re: Drake Equation
----------------------------------------------------------------------

Date: 19 Apr 90 16:57:41 GMT
From: convex![e-mail]  (Edward V. Wright)
Subject: Re: Pegasus launch from Valkyrie  (or ...

[e-mail] (Fraering Philip) writes:


>Third Millenium Corp., also abbreviated as MMI, had been (and may still be)
>seeking development money for a design for a mini-shuttle called the
>"space van." The design was never frozen; one of the early ones involved a
>vehicle that launched from a 747 which could either go into orbit itself on
>the last gasp of fuel, with enough weight for one pilot and retrorocket fuel,
>or could carry a space stage up to Mach 5 or so.

This version of the Space Van was for passenger, including tourist,
flights.  The payload was actually one pilot and five passengers,
if memory serves me right.

>The space stage could carry
>3000 kg into orbit. The Space Van itself was recoverable; it had 6-8 RL-10
>engines. The space stage had one, but it was not recoverable, except maybe
>if the Space Van went up and recovered it.

There were, in fact, plans to do this.  Only the engine module would have
been recovered, the Space Stage propellent tanks and payload fairing,
being cheap, would be expended.  One Space Van mission could recover
several Space Stage propulsion packages.

>It should be noted that the RL-10 cryogenic engine is the oldest liquid
>hydrogen engine ever used; it may have even been the first.

It is also one of the most reliable engines ever built.  It has been
used on the Centaur upper stage for more than 20 years without a single
inflight failure.  Although not designed as a reuseable engine, its
ability to sustain multiple restarts and long firing life -- the qualities
you need in a reuseable engine -- have been demonstrated in static firings
under simulated space conditions.

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

Date: 19 Apr 90 03:34:47 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: B70/B58 - Pegasus launch

In article <[e-mail]> [e-mail] (Duane P Mantick) writes:
>All of this may be a moot point, however, in the case of the Valkyrie.
>There is no such thing as a wing "hard-point" on this bird.  In addition
>the constuction of the main fuselage bottom is such that it might
>not be possible to put in separation equipment ...

The folks looking at using a Valkyrie to launch an X-15 successor concluded
that the best place to put it was on top, well aft.  They were serious about
it, so it's presumably possible.  As Duane points out, though, #2 was a
much better aircraft than #1, and the X-15-plus folks needed #2.

>How would a 1990's technology Valkyrie perform? ...

How much would it cost?  The two XB-70s cost their weight in gold, and
they were the heaviest things in the sky...

>... I suspect that better engines are available
>now off-the-shelf than the J93 ever was...

Not ones cleared for Mach 3 cruise, I'm afraid.  Probably the best you
could do right now would be Mach 2.2-rated Olympus engines meant for
Concorde; I *think* they are still in production, at some miniscule rate.
The Blackbirds' J-58 has been out of production for a long time, and the
modified Gyron Juniors for the Bristol T.188 probably weren't ever *in*
production.  And that is basically it for supersonic-cruise aircraft
outside the USSR.

>Ah well, such is the stuff dreams are made of.

Alas.
--
With features like this,      |     Henry Spencer at U of Toronto Zoology
who needs bugs?               | uunet!attcan!utzoo!henry [e-mail]

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

Date:     Wed, 18 Apr 90 23:52 MDT
From: <[e-mail]>
Subject:  Re: Last year's BIG asteroid...

Regarding the posting asking about a *large* meteor that "nearly" hit the
Earth last year:

03/21/1989 A 1-mile diameter asteroid came within 1/2 million miles of Earth.

I remember hearing on the *radio* that the object in question was not detected
until it was already heading away from earth.  Take this for what its worth:
I remember some "scientist" type saying that the effect of an object this size
striking land would be 100 times greater than detonating all nuclear weapons
on the planet at the same time & in the same place.  Further, he said that if
the object had struck an ocean, the resulting tidal wave would be a mile high,
& would slosh over the Sierra Nevadas.  They also talked about nuclear winter,
dinosaurs, & mentioned that on the outside that all life on earth might be
extinguished (*sigh*).
                                    Robert "Don't Flame Me" Murdock
                                    University of Colorado at Colorado Springs

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

Date: 19 Apr 90 14:51:39 GMT
From: mailrus!cs.utexas.edu!sdd.hp.com!elroy.jpl.nasa.gov![e-mail]  (John Ho)
Subject: [HELP] Insult

Well, this was posted on one of the newsgroups.. I consider this a great
insult to us JPL/Caltech.. Your help is needed... Please email to me..
Sorry, but I am not an astronomy major.. I only know computer...
Thank you very much...

>1. Name the inner planets and outer planets.
>2. List the planets in the order of distance from the Sun
>   (not Sun in California, I know it's hot there, too).
>3. Name the farthest planet that was visited by one of NASA spacecrafts.
>4. Name that spacecraft
>5. Give the date of that visit
>6. Name the sister planet of Earth

>I think one of Cowsteak students will get this because they live in
>the same town with NASA's Jet Propulsion Laboratory (the one that
>manages the spacecraf).

~John

[e-mail]

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

Date: Wed, 18 Apr 90 19:49:00 EDT
From: [e-mail] (Alan Duester)
Subject: Re: Pegasus launch techniques

I recall seeing an article about a year or two ago about how
OSC/Hercules was going to switch launch airplanes after the first dozen
or so test flights. At that time, the plan was for a dedicated, modified
MD-11 or DC-10, with longer landing gear, and a slot cut in the plane's
belly to accept the tail fin.

Obviously, this is not a supersonic launch technique. I don't know what
the performance differential between it and the B-52 would be either.
However, those things carry a lot of typically overweight people, so it
might be able to move fast and high, 'specially if you're not worried
about fuel economies like the airlines supposedly are.

Does anyone know anything concrete on this?

Sorry if I missed an earlier note on this, I lost a week of Digest.

=========================================================================
                     "The farther it gets from the bench it was built on,
                      the more real the real world gets."  - Todd Johnson
Al Duester, Ocean Engineer, MS S201   #  SPAN: 6308::capnal
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------------------------------

Date: 19 Apr 90 17:39:02 GMT
From: mailrus!umich!terminator!um.cc.umich.edu![e-mail]  (Gavin Eadie)
Subject: Re: voyager images on cd

>> In article <[e-mail]>, [e-mail] writes:
>>
>> I am interrested in obtaining the images from the Voyager Neptune

> In article <[e-mail]> [e-mail] writes:
> the images are available on CD and the IMDISP software works with VGA,

In fact the Neptune images are not yet released. Jupiter, Saturn and
Uranus are available from NSSDC on CD-ROM. Mine are at home but I think
there are about 9 of them to date and the Neptune encounter will provide
the final 1 or 2 in this excellent collection.

---
Gavin Eadie, Associate Director
The University of Michigan Computing Center
Ann Arbor, Michigan 48103-4943

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

Date: 19 Apr 90 19:01:40 GMT
From: fernwood!portal!cup.portal.com![e-mail]  (Mark Robert Thorson)
Subject: Re: space tomatoes

I don't know about tomatoes, specifically, but in most members of Solanum
the leaves and other green parts of the plant are poisonous.  Even a green
potato can be poisonous, which is why you're supposed to keep potatos in
the dark.

I can easily imagine a morphological mutation which could leave a plant
confused as to whether it was making a fruit or a leaf.  A leafy tomato
fruit might indeed be a poisonous thing.

It might educational for NASA to explain this to the students.  They could
pass out pictures which show tomatoes which are safe to eat (pictures of
normal tomatoes) and tomatoes which should not be eaten (pictures of artist's
conceptions of mutant tomatoes).

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

Date: 18 Apr 90 18:51:12 GMT
From: att!cbnewsh![e-mail]  (lawrence.m.geary)
Subject: Re: Needles

In article <[e-mail]> [e-mail] (Gord Deinstadt) writes:

>visual astronomers) and doomsayers.  The launch took place, the "needles"
>were invisible from the ground except at resonant microwave frequencies,
>and within a month or two they had all re-entered.

No so. The needles were visible from the ground. Shortly after the
experiment Sky & Telescope published a photograph showing several of
the needles in orbit.
--

     --Larry: [e-mail]

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

Date: 19 Apr 90 03:55:42 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Questions about the Voyagers

In article <[e-mail]> [e-mail] writes:
>One of the Voyager mission planners gave a talk here recently.  He said
>that Voyager 1 could have gone on to Pluto after Saturn (and some of the
>ground crew wanted it to, including the speaker), but to do so would
>have meant omitting the close fly-by of Saturn's moon Titan.

True; I should have said "fixed by the use of gravity-assist maneuvers,
and by high-priority science objectives, at the planets closer in".
Remember that the original name for Voyager was Mariner Jupiter-Saturn.
The birds were basically designed entirely for Jupiter and Saturn, with
the reservation that nothing in their design *preclude* going further.
And major science objectives at Jupiter and Saturn took priority over
later encounters.  In particular, a close encounter with Titan was the
number-one priority at Saturn.  If Voyager 1 had failed before Titan
encounter, Voyager 2 would have flown it and the Uranus-Neptune trajectory
would have been abandoned.  We got lucky!
--
With features like this,      |     Henry Spencer at U of Toronto Zoology
who needs bugs?               | uunet!attcan!utzoo!henry [e-mail]

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

Date: 19 Apr 90 04:30:51 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries

Thanks to Roger Noe for posting a clear summary of the truth about the
AS-204 test fire and (versus!) the Apollo 13 mission.  It's astonishing
how garbled "history" gets!  Personally I would think people would buy
a book -- ANY book -- about the space program before posting here, but
hey! they don't ask my opinion on these things.

In article <[e-mail]> [e-mail] (Roger Noe) writes:
>Trivia time:  The nickname of the Apollo 13 command module was Odyssey,
>after the ship in the movie "2001".  The lunar module, which served as
>the astronauts' "lifeboat", was nicknamed Aquarius.

Keep this in mind when and if you see FOR ALL MANKIND.  There is a scene
midway through with a tape recorder twirling in microgravity, playing
"Also Sprach Zarathustra."  When you see it, get ready!

--
"We must never forget that if the war in Vietnam    \ $   Tom Neff
is lost... the right of free speech will be          X    [e-mail]
extinguished throughout the world." -- RN 10/27/65  $ \   uunet!bfmny0!tneff

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

Date: 19 Apr 90 00:24:58 GMT
From: zaphod.mps.ohio-state.edu!lavaca.uh.edu!jetson.uh.edu![e-mail]  (A JETSON News User)
Subject: Re: Winch Launch as first stage.

You want a winch to do the job. Take a helicopter rotor hub, gearbox
 and turbine engine. add a cable drum. should make one fast winch.

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

Date: 19 Apr 90 22:50:27 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Re: Abundance of stars

[e-mail] (Christopher Neufeld) writes:
>In article <[e-mail]> [e-mail] (Dan Tilque) writes:
>>
>>There are about 50 star systems containing about 70 stars within 16 ly
>>of Earth.  If this is a representative sample (a reasonable assumption)
>>that gives about 1500 star systems in that 50 ly radius.
>>
>   Well, by an odd coincidence I was at the planetarium yesterday. There
>is a very interesting scale model of the stars within 50 light years.
>The recorded voice claims that "all 787 stars within 50 ly are present"
>in the spherical model. Beacuse many stars are doubled or tripled up,
>this gives considerably fewer than 1500 star systems.

No, estimate was based on the known number of star systems, not stars.  A
star system may include one or more stars gravitationaly bound plus other
riff-raff like planets and such.

The reason they had only 787 is that they probably had only the *known*
stars within 50 ly.  There are many low luminosity M type dwarfs within 50
ly whose parallax has not been measured yet.  Actually, there are probably
a few with 16 ly which haven't been measured yet.

Here's how I got my number:

All the lists of nearby stars that I've seen have about 45 star systems
going out to 16 ly in them.  Figuring that we've missed a few I rounded
up to 50.  Then I noted that 50 ~= 3 * 16 which meant that the volume
of a 50 ly spere is about 27 times that of the 16 ly sphere (I just
figured it out on a calculator and it's really about 30 time larger).
50 * 27 = 1350 so I rounded up to 1500 (which actually comes out about
right with 30x).

Of course, this is all dependant on our having discovered most of the
stars out to 16 ly.

---
Dan Tilque    --    [e-mail]

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

Date: 19 Apr 90 22:18:55 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Very long wavelength antenna (was Re: Drake Equation

[e-mail] (Daniel Briggs) writes:
>I
>remember reading a science fiction story at one point that involved an ultra
>low frequency antenna, but can't for the life of me remember what it was.

You're probably thinking of a proposal for one in IMPERIAL EARTH by
Arthur C. Clarke (amazing how often his name comes up in this group,
isn't it?).  That proposal was for one of fairly modest wavelength -- a
few kilometers, if I remember correctly.

---
Dan Tilque    --    [e-mail]

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

End of SPACE Digest V11 #291
*******************