Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_3/V13_374.TXT

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Subject: SPACE Digest V13 #374

SPACE Digest                                     Volume 13 : Issue 374

Today's Topics:
              Timberwind fallout
             Eclipse Photography
        Re: Underground Nuclear Test in Nevada
             Re: HST in-orbit Maintenance
         Re: NY Times Article: Nuclear rocket
         Re: Nova: The Dark Side of the Moon
         Re: Space Stations, Money, Startrek
         Re: Space Stations, Money, Startrek
             Space-Investors List
         Re: Commercial Space news (5 of 12)
         Re: Space Stations, Money, Startrek
            Re: Timberwind fallout
              mexico/eclipse:need info!

Administrivia:

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

Date: 4 Apr 91 22:49:55 GMT
From: hpda!hpcupt1!hpisod2![e-mail]  (Jim McCauley)
Subject: Timberwind fallout

Who among your has any really good stuff on the recently-blown (that
is to say, formerly black-budgetted) Timberwind nuclear heavy-lift
launch vehicle project?

I'm particularly interested in any connections that Tinberwind may
have had with the old Dumbo high-thrust nuclear rocket program that
limped through Los Alamos in the late 1950s, starved for cash because
all the nuclear rocket money was going to the high-impulse Rover/NERVA
program.

Jim McCauley    [e-mail]
Disclaimer: I speak the truth, but only on my own behalf.

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

Date: 5 Apr 91 16:54:32 GMT
From: ubc-cs!alberta!herald.usask.ca!ccu.umanitoba.ca!bison!sys6626!draco!swrdpnt![e-mail]  (Ford Prefect)
Subject: Eclipse Photography


  One point tht should be mentioned to prospective eclipse photographers:
Don't expect to get good results with new equipment that you bought just
for the eclipse!  You should be completely familiar with your camera
system, and should have done some photography of the moon with it before.
   The suggestion of making a checklist of exposure times and f/stops is
a good idea.  Another idea is to practise your routine over and over
until you can do it with your eyes closed.  Then try it in a dark room.
It gets quite dark during totality, so knowing your equipment is essentia
to get good results.
   If you're travelling to Mexico, the sun will be nearly overhead during
totality, so  a useful accessory is a right-angle focussing magnifier. It
will make things easier on your neck.
   Above all, don't spend the whole time photographing; LOOK at it!  A
solar eclipse is an awsome sight that will live in your memory much more
vividly than your best photograph of it.
             Scott Young


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Reply to: [e-mail]

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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

Date: 7 Apr 91 00:10:13 GMT
From: fernwood!portal!cup.portal.com![e-mail]  (Mark Robert Thorson)
Subject: Re: Underground Nuclear Test in Nevada

Hema Murty says:

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

I agree that it's a disgrace that underground nuclear testing is allowed
to continue.  I've always wanted to see a nuclear explosion from the
closest possible safe distance, and underground testing has denied me
this chance.  Furthermore, the termination of open-air testing is what
really put the kabosh on nuclear-powered launch vehicles, which are vitally
important to the construction of large-scale space habitats and manned
exploration of the solar system.  What's really galling is that even our
smallest and cleanest bombs can't be used above-ground, which puts a severe
crimp in some of the most promising anti-missile technologies.
Let's join Hema Murty's call for an end to underground testing!

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

Date: 6 Apr 91 22:07:56 GMT
From: agate!bionet!uwm.edu!zaphod.mps.ohio-state.edu!rpi![e-mail]  (Michael V. Kent)
Subject: Re: HST in-orbit Maintenance

In article <[e-mail]> [e-mail] (George Muzyka) writes:
>Method:
>1. Assembly a large cubical frame structure made up of trusses and beams,
>   much like on one of the U.S. Shuttle missions; the Large Array. (?)
>2. Manouevering of this cubical frame so the target spacecraft/satellite
>   is within its centre. Need plenty of leeway space, but also some
>   beams with attachment arms to temporarily hold the target object
>   still in attitude relation to the frame.
>3. The covering of the cubical frame with a temporary skin, to hold
>   in any small or medium-sized items that may slip out of astronaut
>   gloves and drift away. Aid of a laser sensitive moving debris device
>   could show where a small item is heading. The skin/covering material
>   could be lined with a catchy texture (not a sticky adhesive!) to
>   prevent rebounds/deflections.
>4. The target spacecraft/satellite could now be opened and large
>   sections separated with the attachment arms keeping hold of each
>   section.
>5. After in-orbit repair, and reassembly, one side of the cubic frame's
>   covering could be removed and the whole framework carefully manoeuvered
>   away from the target, and the framework probably dismantled until
>   next time.
>

[Further info on in-orbit servicing deleted.]

>[e-mail]         |  /                  /~~
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Such a servicing bay was indeed planned for Freedom.  If you've seen any
pictures of Freedom Phase II you may have noticed a large white structure in
an upper corner of the rectangular frame.  This was to be a satellite serviceing
facility, and it was to be large enough to hold any of the Great Observatories.
Tools would be stored there to aid in refueling and refurbishing satellites.  I
believe it may have been pressurized too, but I'm not sure.  That eliminates
problems concerning the gloves and bulky suits.

These plans are a few years old and date back to the time when NASA planned to
have an Orbiting Maneuvering Vehicle parked at the Station and and Orbiting
Transfer Vehicle to ferry satellites to and from GEO for repair.

Michael Kent                                              [e-mail]

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

Date: 6 Apr 91 17:30:25 GMT
From: agate!bionet!uwm.edu!cs.utexas.edu!ut-emx!nowhere![e-mail]  (Steven King)
Subject: Re: NY Times Article: Nuclear rocket

In article <[e-mail]> [e-mail] (Raymond Lister) writes:
>
>    WASHINGTON (UPI) -- The Pentagon is trying to build a nuclear-powered
>rocket to boost huge payloads, satellites or weapons into space,
>scientists and government sources said Wednesday.
>    Rather than using conventional chemical rocket fuels to generate a
>blast of hot gases to propel a rocket into space, the project involves
>vaporizing liquid hyrdogen into a far stronger exhaust stream by passing
>it over a bed of nuclear fuel pellets generating heat as high as 3,000
>degrees.
>    Internal government documents, obtained on the condition that their
>source not be divulged, show the program is still young and years away
>from completion. The documents also say the government already has
>studied safety hazards that might be associated with a sub-orbital test
>flight that could pass over the Antarctic and New Zealand.


   Eh? This sounds like the old fashioned "project in search of a
 mission" combined with media hyperbola. The fluidized bed reactor
 project ( scandi ? ) has been around atleast since the mid eighty's.
 I first saw papers reguarding it as a part of an aero & astro class
 at the UW; it couldnt have been too highly classified, as it was
 availible to students. At that time it was being proposed a megawatt
 powersupply for space applications that would need lots of power very
 quickly and for a short period ( ie. SDI ). It would use the superheated
 hydrogen to drive turbines to drive the generators... I wouldnt be
 surprised if this wasnt more of the same; that is, proposals and
 funding to keep research ongoing as opposed to a "real" project.

   There were, as I remember, a few technical problems to be considered.
 Pump too much energy into diatomic hydrogen and it tends to disassociate,
 sucking up a substancial amount of energy, pump more energy into it
 and one gets a wild mixture of H-, H+, H2, etc., this both limits the
 specific impulse and produces a very reactive exhaust that needs to be
 considered in the design of the nozzle and even the fuel pellets.

   I can't, for the life of me, remember how it was to be moderated. But
 I do remember that if the vehicle was forced to undergo reentry, the
 proposal called for the fuel to be discharged at a high altitude so
 that the fuel pellets would be vaporized and any radioactive residue
 would be uniformly distributed...


--
If it don't stick, stink, or sting
It ain't from Texas.
                                        ..!cs.utexas.edu!ut-emx!nowhere!sking

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

Date: 7 Apr 91 03:57:10 GMT
From: [e-mail]  (William Dow Rieder)
Subject: Re: Nova: The Dark Side of the Moon

Henry Spencer writes:

>Don't know, I haven't seen the program. :-)  (I don't own a television set.)
                    ^^^^^^^^^^^^^^^^^^^^^^
You have my deepest respect :-)  I didn't used to have one, but my wife
did when we got married. Oh well.  Saves a lot of your time, I'll bet.

                    W. Dow Rieder

     When the only tool you have is a hammer, all your problems
start to look like nails...

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

Date: 6 Apr 91 22:23:33 GMT
From: dog.ee.lbl.gov!hellgate.utah.edu!caen!zaphod.mps.ohio-state.edu!rpi![e-mail]  (Michael V. Kent)
Subject: Re: Space Stations, Money, Startrek

In article <[e-mail]> [e-mail] (Steve Emmerson) writes:
>In <[e-mail]> [e-mail] (Michael V. Kent) writes:
>
>>...  The major
>>task for Freedom is to learn how to live and work in space.  Once we have
>>that we can work on expanding the facilities.
>
>Odd.  Don't we (i.e. the human species) already know how to live and
>work in space?  Haven't humans spent up to a year in space with no
>major problems?

No, WE don't.  WE have only been to space for brief visits, with the exception
of an 84 day mission in 1973.  While it did provide valuable data, it answered
only a few or our questions -- questions which need to be answered.

There are some humans which know more than we do, but since WE don't have
access to their data, we'll have to learn ourselves.  True, we will be
re-inventing the wheel, but the cart is our own invention.
>
>>..e  Fourth, astronauts will spend about 1.5 hours a day exer-
>>cising.  One of the things we need to know is what exercise is necessary
>>and why.  Freedom will help provide that answer.
>
>Odd.  Don't we already know the answer to these questions?  (And isn't the
>necessary amount of excercise closer to 4 hours per day?)

Obviously not.  :) From "Space Station Freedom: A Foothold on the Future"...
"To maintain physical fitness each crew member will go through two 45-minute,
individualized exercise programs a day using the treadmills and stationary
bicycles in the habitation module."  This is based on experience with Skylab
and the Space Shuttle.  Granted, this may turn out to be inadequate, but then
we will answer your other question with "No, we didn't know."

>
>Steve Emmerson        [e-mail]        ...!ncar!unidata!steve

Michael Kent                                      [e-mail]

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

Date: 6 Apr 91 18:28:40 GMT
From: groucho![e-mail]  (Steve Emmerson)
Subject: Re: Space Stations, Money, Startrek

In <[e-mail]> [e-mail] (Michael V. Kent) writes:

>...  The major
>task for Freedom is to learn how to live and work in space.  Once we have
>that we can work on expanding the facilities.

Odd.  Don't we (i.e. the human species) already know how to live and
work in space?  Haven't humans spent up to a year in space with no
major problems?

>...  Fourth, astronauts will spend about 1.5 hours a day exer-
>cising.  One of the things we need to know is what exercise is necessary
>and why.  Freedom will help provide that answer.

Odd.  Don't we already know the answer to these questions?  (And isn't the
necessary amount of excercise closer to 4 hours per day?)

Steve Emmerson        [e-mail]        ...!ncar!unidata!steve

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

Date: 5 Apr 91 04:32:00 GMT
From: sgi!cdp![e-mail]
Subject: Space-Investors List



Can anyone provide the Internet or Bitnet address for the space-investors
list?  I've shifted accounts and seem to have left that information
behind.

Thanks in advance.

Ken Donow
W.L. Pritchard & Co.
7315 Wisconsin Avenue
Suite 500E
Bethesda, MD  20814

Voice:    301-645-1144
Fax:    [phone]
Email:[  cdp![e-mail]

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

Date: 6 Apr 91 21:55:18 GMT
From: swrinde!zaphod.mps.ohio-state.edu!rpi![e-mail]  (Michael V. Kent)
Subject: Re: Commercial Space news (5 of 12)

In article <[e-mail]> [e-mail] (Charles Frank Radley) writes:
>Oh yes, when the ELV companies say they are not subsidized by the
>US govt, ask who owns their tooling.......
>   A paraphrasing of Art Dula quoted in the LA Times.

     Is this a trick question?  Who do you think owns their tooling?

Michael Kent                                               [e-mail]

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

Date: 7 Apr 91 00:10:02 GMT
From: usc!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Space Stations, Money, Startrek

In article <[e-mail]> [e-mail] (Steve Emmerson) writes:
>Odd.  Don't we (i.e. the human species) already know how to live and
>work in space?

Yes, in the sense that we know some approaches that work.  No, in the sense
of knowing all there is to be known about it, and being able to estimate
the effectiveness of new approaches before trying them.

>Haven't humans spent up to a year in space with no major problems?

Two humans have done this, without major problems.  More data would be
very welcome, since future efforts are unlikely to precisely duplicate
the exact set of conditions under which this was done.  We have an
existence proof, but not enough data to confidently draw graphs and
define the boundaries between acceptable and unacceptable conditions.

>>... One of the things we need to know is what exercise is necessary
>>and why...
>
>Odd.  Don't we already know the answer to these questions?

No.  We have vague notions at best.  What's wanted is enough detailed
knowledge to guide engineering design of future space activities.  That
we do not have.
--
"The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 are all true."  -D. Harrison|  [e-mail]  utzoo!henry

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

Date: 7 Apr 91 04:37:31 GMT
From: usc!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Timberwind fallout

In article <[e-mail]> [e-mail] (Jim McCauley) writes:
>I'm particularly interested in any connections that Tinberwind may
>have had with the old Dumbo high-thrust nuclear rocket program ...

If the descriptions of Timberwind's hardware -- a fluidized-bed pellet-fuel
reactor -- are correct, none whatsoever.

>all the nuclear rocket money was going to the high-impulse Rover/NERVA
>program.

Uh, we may have a slight misunderstanding here:  Dumbo had *both* higher
thrust and higher exhaust velocity (aka specific impulse) than NERVA.
The difference between the two was ambitious high-performance vs. cautious
low-performance, so it's no surprise which got canned when money was tight.
--
"The stories one hears about putting up | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 are all true."  -D. Harrison|  [e-mail]  utzoo!henry

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

Date: 6 Apr 91 18:53:34 GMT
From: agate!bionet!uwm.edu!zaphod.mps.ohio-state.edu!casbah.acns.nwu.edu!uicvm.uic.edu![e-mail]
Subject: mexico/eclipse:need info!

I am travelling down to Mexico this July to view/photograph
the eclipse. We are trying to arrane it so we will be in
Tuxpan on the day of the eclipse. There is also a chance
that we will be in Guadalajara (sp?) on that day. Does anyone
have the times that the eclipse is supposed to occur? We
need the info ASAP so we can make travel arrangements. Thanks
in advance.
                    Christina U29012@UICVM (bitnet)
                              [e-mail] (internet)

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

End of SPACE Digest V13 #374
*******************