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Subject: SPACE Digest V10 #404

SPACE Digest                                     Volume 10 : Issue 404

Today's Topics:
               Re: Simpler space suits?
            Re: Nuclear Reactors in Space
       Re: March 1990 ANALOG article on self-refueling vehicles
            Treaties and reactors
            Re: Nuclear Reactors in Space
           Re: March 1990 ANALOG article on self-r
         NASA Headline News for 01/08/90 (Forwarded)
               Re: Reactors in space II
            Re: Nuclear Reactors in Space
               Re: Space Suits
              Outer Space Treaty
----------------------------------------------------------------------

Date: 9 Jan 90 05:22:00 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Simpler space suits?

In article <[e-mail]> [e-mail] (John Sahr) writes:
>>The real problem is arms and legs, and they are just too useful to
>>replace with something mechanical.
>
>One does not obviously preclude the other.  It is not clear to me why
>a suit must be strictly anthropomorphic.  Why not have a suit which is
>more like a walking glovebox rather than a walking glove?

The thing is, *the torso is not the problem*.  Current suit designs tend
to have rigid or semi-rigid torsos already.  It would not be difficult
to make the torsos larger, except that it would make the suits clumsier.
So far it doesn't seem worth it; nobody *wants* to stay in a suit for days.
--
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry [e-mail]

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

Date: 9 Jan 90 05:43:33 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Nuclear Reactors in Space

In article <[e-mail]> [e-mail] (SERRE GLENN) writes:
>... Henry (if I may be so familiar), why would one want to
>produce Pu-238 instead of Pu-239 in a breeder reactor?  I thought the whole
>idea was to use the Pu-239 that is easy to generate from U-238 to power the
>reactor (this is in reference to reactors on the moon).

The motive for this particular suggestion was to use the reactor to breed
Pu238 for RTGs.  Pu239 is fine for applications that can lug a whole
reactor along, but many of the smaller ones can't (or don't want the
radiation background that it produces -- Pu238 is unusual in that its
decay produces only the barest hint of gamma rays).

>1) Fuel for these proposed systems.  A recent poster mentioned that nuclear
>and electo-arc rockets wanted hydrazine as a propellent.  What he probably
>meant was that they want hydrogen, because of its low molecular/atomic weight.
>The extra energy you might get from breaking down the hydrazine isn't worth
>the effort when you have all that nuclear energy.

Hydrogen is a better fuel for them, for sure.  However, it is a colossal
pain to store for long periods in space (well, anywhere, actually), and
things like electric rockets tend to want to run for months or years to
make up for their really tiny thrust.
--
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry [e-mail]

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

Date: 9 Jan 90 07:02:35 GMT
From: [e-mail]  (Dean F. Kling)
Subject: Re: March 1990 ANALOG article on self-refueling vehicles

> >No treaty in existence bans space-based
> >reactors, and the Soviets are the only ones operating them at present.
>
> I thought that one of the objections to several of the SDI proposals
> was that they would require orbiting nuclear reactors to power them
> and such stuff was prohibited by the ABM treaty (which, of course, the
> US never ratified, but which we pretty much observe).  Perhaps
> the ABM treaty applied only to nuclear reactors used in conjunction
> with weapons systems.
>
> Anyone have better information or a better memory on this?

[Hazy recollections supplemented by World Almanac for 1990]
    The only limitation of space-borne nuclear material is the
prohibition on "weapons of mass-destruction" in orbit from the Outer
Space Treaty, Jan 1967.  (I believe this was aimed at the FOBS; fractional
orbit bombardment system, which would allow missile attact from the south).

    The ABM treaty (which technically was a protocol that grew out
of SALT-I WAS signed by both the US and USSR (July 3, 1974) and I believe
was ratified by the senate.  The ABM treaty has nothing to do with nuclear
material in space, but limited both the US and USSR to 2 ABM systems, one
for the capital and one for a missile field.  {The Russians chose to
protect Moscow, we chose to defend North Dakota} (I think this was later
mutually amended to one system each, either formally or informally).
      What the ABM Treaty DOES affect is the deployment of the SDI.  No
matter what song and dance you try with semantics, SDI is exactly the system
prohibited by the ABM Treaty (although when the ABM Treaty was signed
all expected systems were basically ground-based missile systems).  In order
to deploy SDI we will have to abrogate the ABM Treaty.

                Dean F. Kling
                [e-mail]

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

Date: 9 Jan 90 13:47:02 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca![e-mail]  (Christopher Neufeld)
Subject: Treaties and reactors

In article <[e-mail]> [e-mail] (Doug Borsom) writes:
>In article <[e-mail]>
>[e-mail] (John Hogg) writes:
>
>>No treaty in existence bans space-based
>>reactors, and the Soviets are the only ones operating them at present.
>
>I thought that one of the objections to several of the SDI proposals
>was that they would require orbiting nuclear reactors to power them
>and such stuff was prohibited by the ABM treaty (which, of course, the
>US never ratified, but which we pretty much observe).  Perhaps
>the ABM treaty applied only to nuclear reactors used in conjunction
>with weapons systems.
>
>Anyone have better information or a better memory on this?

   Well, I seem to remember that the "weapons of mass destruction"
proscription means that the only x-ray lasers possible with today's
technology are forbidden from space. SDI put a lot of faith in these
devices, which are essentially independently targeted laser tubes stuck
inside a nuclear explosive. When the bomb detonates the lasers fire briefly
before being destroyed, and it was hoped that a single detonation could
fire lasers to destroy tens of rockets.
   The stumbling block seemed to be that a nuclear explosive could be
considered a "weapon of mass destruction".

--
 Christopher Neufeld....Just a graduate student  |
 [e-mail]              | The meek can have the
 [e-mail]                    | earth, I want the stars.
 "Don't edit reality for the sake of simplicity" |

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

Date: 8 Jan 90 21:10:37 GMT
From: concertina![e-mail]  (Steve Hix)
Subject: Re: Nuclear Reactors in Space

In article <[e-mail]>, [e-mail] (Tom Neff) writes:
> In article <[e-mail]> [e-mail] (Terry Conklin) writes:
> >There's _no_ way solar cells could generate that kind of power. In the
> >same vein, nuclear power will remain strong and reliable regardless of
> >distance from the sun.
>
> Well, reactors don't care how far from the sun they are per se (as long
> as you don't get too close!), but they do need fuel, and when that runs
> out you have a lot of complicated hardware doing nothing.  Solar arrays
> diminish in effectiveness as distance from the sun increases, but while
> they are effective at all they are just about *permanently* effective.
> And simple, where reactors are complex.  Radioisotope thermal generators

Don't forget that solar arrays (photovoltaics, anyway.  I suppose you could
make a solar thermal-dynamic array...) degrade over time, what with various
energetic particles zipping in.

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

"...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_ 275d

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

Date: 9 Jan 90 13:08:00 GMT
From: [e-mail]
Subject: Re: March 1990 ANALOG article on self-r


A minor quibble: Fractional Orbital Bombardment System (FOBS)
was a way around the space treaty -- fractional orbit being
less than a full orbit was legal.  FOBS was abandoned by the
Soviets for the practical reason of lowered payload and
lessened accuracy.

--paul hager        [e-mail]

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

Date: 8 Jan 90 18:46:58 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 01/08/90 (Forwarded)

-----------------------------------------------------------------
Monday, January 8, 1990                       Audio: 202/755-1788
-----------------------------------------------------------------


This is NASA Headline News for Monday, January 8....



Poor weather scrubbed the launch of the STS-32 mission today.
Launch Director Bob Seick made the decision at 8:56 A.M., Eastern
time, having waited through nearly the entire launch window for
the weather to clear.

Immediately following the scrub order the STS-32 crew began
shutting down orbiter sytems.  Pad crews then began procedures to
drain the propellants from the external tank and ready the
Columbia for launch tomorrow.

The Tuesday launch window opens at 7:35 A.M., Eastern time, and
remains open until 8:33 A.M.  A minor change may be made after
assessment of the LDEF orbital elements this evening.

Weather for Tuesday is much more favorable.



In other launch news...a Delta II rocket is scheduled to launch a
Navstar Global Positioning System satellite into orbit Thursday
from Cape Canaveral.  NASA Select TV will provide coverage of the
launch now scheduled for between 3:50 and 4:11 P.M.



A problem aboard an Ariane 40 booster has delayed the launch of a
Spot 2 Earth resources satellite from Kourou, French Guiana.  It
was schedule for Wednesday, a new launch date has yet to be
announced.


Thomas Utsman has been named Deputy Associate Administrator for
Space Flight.  In his new capacity, Utsman will have
responsibility for the day-to-day management of procurement
activities, assessing program management performance and long
range operational planning under Associate Administrator for
Space Flight William Lenoir.  Utsman has been Deputy Director at
Kennedy Space Center.  Replacing Utsman as Deputy Director of KSC
will be James A. "Gene" Thomas.


            *            *             *            *





-----------------------------------------------------------------
Here's the broadcast schedule for public affairs events on NASA
Select TV.   All times are Eastern.


Tuesday, January 9....

      3:00 A.M.      Near continuous coverage of the STS-32 space
                     shuttle mission begins.  Launch window opens
                     at 7:35 A.M.


Several TV presentations had been scheduled for this week during
the STS-32 mission.  They include an ASTRO-1 mission
presentation,  a quality management presentation and the
Delta/Navstar launch.  Because of the STS-32 launch delay the
schedule is being reassessed.  In addition...numerous STS-32
mission highlights will change.  A revised schedule will be filed
Tuesday.
-----------------------------------------------------------------
These reports are filed daily, Monday through Friday, at 12 noon,
Eastern time.
-----------------------------------------------------------------
A service of the Internal Communications Branch (LPC), NASA
Headquarters, Washington, D.C.

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

Date: 8 Jan 90 21:04:09 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Reactors in space II

It won't make sense to mine fissionable in space anytime soon -- the
cost of mining and enriching it would be large.  Instead, you'd ship
up highly enriched uranium from earth.  Not much is required -- one
tonne of U-235, fully fissioned, yields about 2.5 gigawatt-years of
heat.  It might make sense to reprocess spent U-235 so it can be fully
fissioned, probably by electrorefining of partially burned metallic
fuel elements.

    Paul F. Dietz
    [e-mail]

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

Date: 8 Jan 90 15:18:37 GMT
From: jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Kieran A. Carroll)
Subject: Re: Nuclear Reactors in Space

> From: [e-mail] (Tim Maroney)

> .... If we had sunk one-tenth the money into
> light-weight electrical batteries that we have sunk into fission and
> fusion research, space vehicles would be able to generate all the power
> they would need for outer-solar-system missions while still in the
> inner system and store it....
>
> >RTGs would be useful for medium to long range lunar rovers which
> >have to drive through a two week night.
>
> So would light-weight long-duration electrical batteries.  Just think,
> if we'd started sinking in billions of dollars a year several decades
> ago, as we have for fission and fusion research, we'd have had them
> long hence.

Tim, your statements here assume that such high specific-energy-
capacity batteries are physically possible to produce. If there's a
physical principle waiting to be exploited that could result in such
a thing, then billions of dollars of research would likely be
justified. If there's >no< such principle, however, then no amount
of research spending will result in such batteries. Right?

Now, have you any reason to believe that it is possible to produce
batteries with much higher specific energy capacity (i.e. energy
capacity divided by mass) than those currently available? Say, two
orders of magnitude better than NiCd batteries? I know that a >lot<
of money has been spent on battery research in the last decade (by
NASA, by spacecraft battery manufacturers, by the DOE, by electric-
car proponents; even some by the electric utility companies, who
would love to have cheaper load-leveling devices), and as far as I
have heard that research has not turned up any physical principles
that could be exploited to produce the sort of improvements that you
suggest.

A question: if it turns out to be impossible to produce batteries
significantly better than those currently available, would you still
object to the use of RTGs on spacecraft?

--

     Kieran A. Carroll @ U of Toronto Aerospace Institute
     uunet!attcan!utzoo!kcarroll [e-mail]

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

Date: 9 Jan 90 17:37:46 GMT
From: pioneer.arc.nasa.gov![e-mail]  (Keith Wandry- RCE)
Subject: Re: Space Suits

The September/October issue of AIR & SPACE SMITHSONIAN has an
excellent article on space suits and where the design is headed.

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

Date: 9 Jan 90 16:47:57 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Outer Space Treaty

In article <[e-mail]> [e-mail] (Dean F. Kling) writes:
>    The only limitation of space-borne nuclear material is the
>prohibition on "weapons of mass-destruction" in orbit from the Outer
>Space Treaty, Jan 1967.  (I believe this was aimed at the FOBS; fractional
>orbit bombardment system, which would allow missile attact from the south).

Actually, vice-versa:  FOBS was an evasion of the treaty.  The treaty bans
things like bombs in orbit, but there was a problem with defining "in orbit"
in such a way as not to ban ICBMs, and the solution was that "in orbit" means
at least one complete orbit.  An FOBS only makes about 3/4 of an orbit.
--
1972: Saturn V #15 flight-ready|     Henry Spencer at U of Toronto Zoology
1990: birds nesting in engines | uunet!attcan!utzoo!henry [e-mail]

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

End of SPACE Digest V10 #404
*******************