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Subject: SPACE Digest V11 #99

SPACE Digest                                      Volume 11 : Issue 99

Today's Topics:
Funding is not the Problem (was: Re: Fun Space Fact #1: Launcher Development Costs)
        Re: LDEF - Protection from atmosphere?
            Re: What happened to Pegasus?
                SLC-6
            Re: Voyager Update - 02/23/90
             Re: Experimentation
              Pegasus Update - 02/26/90
         Re: Geosync DSN (was Re: Cheap DSN?)
               Any news on a new comet?
          Re: Spacecraft drives and fuel efficiency
       Re: Did SEASAT See More Than It Was Supposed To?
                 Re: Beanpole
----------------------------------------------------------------------

Date: 28 Feb 90 06:36:59 GMT
From: agate![e-mail]  (William Baxter)
Subject: Funding is not the Problem (was: Re: Fun Space Fact #1: Launcher Development Costs)

In article <[e-mail]>, mccall@skvax1 writes:
>>> is "agate![e-mail] (William Baxter)"

>Yes, and if one really looks one can also find things about what
>NASA originally wanted to build, which has been mentioned by both
>Henry Spencer and myself.  Why do you suppose that that original
>system wasn't built, Mr. Baxter?  Because NASA is a bunch of evil
>people who just want to rip off the American taxpayer?  Hardly seems
>credible, to me.

Development contracts are much more lucrative than research contracts.
There is strong pressure for bureaucracies like NASA or DoD and their
contractors to push into development prematurely, rather than doing the
necessary research.  The shuttle is a perfect example of just this
tendency.  One original goal for the STS was a $100/lb cost to LEO.  The
shuttle is a spectacular failure in this respect.  The NASA officials
who made these wildly optimistic claims of launch cost did not have any
basis for them other than their 'expertise.'  Looking back, it is clear
that they didn't know how much it was going to cost.

The current NASA budget is $12,323 million.  That's plenty of money to
run a government space program.  It may not be enough to run THE space
program, but it shouldn't have to be.

A more fundamental problem is the lack of policy.  There is almost total
confusion between 'research' and 'development.'  There is also no clear
definition of the appropriate roles of government and private industry.
I think that government should support basic research and keep out of
development, leaving the risks and rewards of development to commercial
industry which is much better suited to it.

>It will also not be solved by just 'bashing' them for it.  If you
>want to do something to correct it, start at the top where such
>attitudes are engendered, and that means starting with the Congress
>and the way the budgetary process is run (or not run) from the top.

That is why I am working with my congressman to pass HR2674, and to
terminate development boondoggles like Space Station, ALS and NASP in
favor of basic research projects.

William Baxter

ARPA: web@{garnet,brahms,math}.Berkeley.EDU
UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web

P.S.
Is this a sentence? -->                          As is, it would
>appear, assuming that any disagreement with their opinions
>automatically means that the person disagreeing must have whatever
>their particular generalized stereotype for the attitudes of 'the
>enemy' is.

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

Date: 28 Feb 90 17:19:55 GMT
From: usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: LDEF - Protection from atmosphere?

In article <[e-mail]> [e-mail] (Will Martin) writes:
>... I would have thought that the LDEF is being so contaminated
>by exposure to Earth's atmosphere that a lot of the information that could
>have been obtained from it has been lost...

It would have been nice to keep it in vacuum, but the fact is, it's
very difficult.  The most fundamental problem is simply that the shuttle
cargo bay can't do that.  There are a host of subsidiary problems with
handling and so forth.  Exposing it to air is less than ideal but would
be very hard to avoid.  That's one of the reasons why the crew spent
several hours photographing it in space before reeling it in.

>By the way, during the retrieval, at least several of the thin-film panels
>were fluttering, as if in a breeze. What was causing that? Thruster exhaust
>from the shuttle? If so, didn't THAT contaminate and ruin some of the test
>panels?

I haven't seen footage of the retrieval, but the obvious possible causes
are shuttle thrusters and movement of LDEF itself.  Yes, thruster exhaust
is a concern, to the point that some designs for future spacecraft have
included a second low-contamination thruster system for maneuvering close
to space stations etc.  Again, I think it's a nuisance but hard to avoid
with current equipment.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: 26 Feb 90 18:27:58 GMT
From: cs.utexas.edu!hellgate.utah.edu!uplherc!esunix!bambam![e-mail]  (Bob Pendleton)
Subject: Re: What happened to Pegasus?

From article <[e-mail]>, by [e-mail]:
> Does anyone know what's been going on with the Pegasus launcher
> by Orbital Sciences Corp. lately? Were'nt they supposed to launch
> soon?

Please, don't forget that Hercules has a big part in Pegasus. I've
heard a rumor that electrical problems were discovered during captive
carry tests. It can't fly until those are fixed. OSC did the
electronics.

There was also a problem with insulation blowing off of the wing.

On the other hand, OSC/Hercules has signed up a couple of more customers.

            Bob P.
--
              Bob Pendleton, speaking only for myself.
UUCP Address:  decwrl!esunix!bpendlet or utah-cs!esunix!bpendlet

                      X: Tools, not rules.

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

Date: Thu,  1 Mar 90 13:14:23 PST
From: Peter Scott <[e-mail]>
Subject: SLC-6
X-Vms-Mail-To: EXOS%"[e-mail]"

Has anyone heard of any plans for de-mothballing the Shuttle Launch
Complex at Vandenburg?  BTW, what happened to SLC-1 thru -5?

Peter Scott ([e-mail])

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

Date: 28 Feb 90 21:10:12 GMT
From: psivax![e-mail]  (Torkil Hammer)
Subject: Re: Voyager Update - 02/23/90

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
#     On February 14, an RFSCMD (threshold) test was executed by the DSN station
#in Goldstone, California. Due to procedural errors during the test, the test
#was not completely successful. Procedural changes will be made before the next

  Is this the same as an (inadvertent) RTFM test? :-)

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

Date: 28 Feb 90 16:30:48 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Experimentation

In article <[e-mail]> [e-mail] (Joel Lessenberry) writes:
>        I understand that these days the world would rather simulate
>        than experiment, but... has anyone even worked in planning
>        simple missions to actually demonstrate new propulsion
>        technologies?  Surely this type of experimentation could be
>        done by *someone* without the 20 year, multi billion dollar
>        design cycles which are so prevalent.

It could be done, yes, and there have been various proposals to do it,
e.g. the Lunar Getaway Special proposal which would (finally!) space-test
ion propulsion.  The problem is that nobody is funding such things.  NASA
basically gave up on advanced technology work in the post-Apollo crunch.
They've been talking about getting back into it in a serious way, but so
far it's been mostly talk.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: 27 Feb 90 01:43:07 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Pegasus Update - 02/26/90


                      Pegagus Update
                    February 26, 1990

     The launch of the Pegasus satellite (Pegsat) is
now scheduled for March 13, according to project officials.  The
satellite will be carried aloft by a NASA B-52, from which it will
be launched at 40,000 feet altitude about 50 miles west of
Vandenberg Air Force Base, CA.  Project Manager Bob Pincus and
other members of the project are in California this week readying
the 422-pound satellite for the flight.  Yesterday, they conducted
a simulated flight.  Today and tomorrow, they will conduct
spacecraft checks.  Thursday, they will install the thermal
blankets, and on Friday they will load the unarmed chemical
canisters.  The three-function payload, developed at Goddard, will
carry instrumentation to measure variations in launch vehicle and
spacecraft attitude, temperature, pressure, structural loading and
vibrations.  It also will dispense a small, experimental
communications satellite for the Navy.  Once those two operations
are complete, NASA will use Pegsat to conduct two barium chemical
releases.  The discharges will be made between March 15 and March
30 over central Canada.

 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 1 Mar 90 06:00:31 GMT
From: sco![e-mail]  (Nathaniel Ingersoll)
Subject: Re: Geosync DSN (was Re: Cheap DSN?)

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
:BIG guidable antenna arrays are not feasible for earth orbit. A 70 meter
:antenna on the earth weighs 8 million pounds. The cost of placing such
:an antenna into orbit would be astronomcal. And this is before the antenna

The antenna on Earth weighs 8 million pounds because earch has a lot
of gravity that the antenna has to avoid folding due to.
I'm sure you could build a much lighter antenna if you don't have
to worry about supporting it.


:
: Ron Baalke                       |    [e-mail]
--
________________________________________________________________________________
  I told the police that I was not injured,
  but on removing my hat, I found that I
  had a skull fracture.                     -- from an insurance accident form

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

Date: 27 Feb 90 13:36:58 GMT
From: usna![e-mail]  (LT Peter A. Nardi)
Subject: Any news on a new comet?

Sender:
Reply-To: [e-mail] (Peter A. Nardi (CompSci) <nardi@usna>)
Followup-To:
Distribution:
Organization: U.S. Naval Academy, Annapolis
Keywords: comet

   I read in a recent newspaper article that there is a new comet
approaching the Sun.  It's called Comet Austin, and was discovered
by an amatuer astronomer in Australia (I think).  The article said
if the comet tracks as predicted that it could prove to be a pretty
spectacular event. (Around magnitude zero in the early morning hours
near the end of April.)  The article was quick to point out that
comets as a rule are VERY fickle and it's too soon to tell exactly
what it will do.
  Has anyone else heard anything about this?


-=<Pete>=-
pete nardi
[e-mail]

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

Date: 28 Feb 90 07:29:02 GMT
From: unisoft!hoptoad![e-mail]  (Tim Maroney)
Subject: Re: Spacecraft drives and fuel efficiency

In article <[e-mail]> [e-mail] (David Schneider)
writes:
>>...an academic advisor (back when I was a physicist-to-be) showing me
>>his back-of-the-envelope calculations that showed an matter-anitmatter
>>reaction for 1G acceleration (producing gamma rays as a matter of efficiency)
>>would fry the departure site...

Unless there is no "departure site".  An antimatter spacecraft would
probably be built in orbit or on the moon, but even if not there's no
good reason to run the drive in the atmosphere.  It can be lifted into
space by "conventional" means, and it would probably use chemical
propellants to take it a good distance from the Earth before firing up.

I think the antimatter should be produced in lunar factories and should
never enter the atmosphere regardless.  It's just too dangerous to the
ecosystem, and the containment is intrinsically iffy.  But the basic
craft could be built on the Earth if that was cheaper.

In article <[e-mail]> [e-mail] (Henry Spencer)
writes:
>It all ends up as gamma rays (or stray
>electrons and positrons) eventually, but you want that happening as far
>away as possible, a kilometer or so back in the exhaust jet when the muons
>decay.  There *are* a lot of gamma rays even so, enough to be a problem.

Yeah, and it's a little tricky to outrun them... :-)

>You may not have noticed :-), but all existing space propulsion systems
>fry the immediate vicinity when they take off...

Hmm.  How much antimatter would you have to annihilate to escape the
gravity well?  Micrograms per launch?  I tend to think it would "fry"
the immediate vicinity a little worse than extreme heat does.  Wouldn't
there be a good deal of residual radiation, especially after multiple
launches of large craft?  Current launch pads are reusable pretty
quickly, and the atmospheric pollution is insignificant.
--
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, [e-mail]

"Starting in a hollowed log of wood -- some thousand miles up a river, with an
 infinitesimal prospect of returning!  I ask myself 'Why?' and the only echo
 is 'damned fool! ... the Devil drives!"
    -- Sir Richard Francis Burton in correspondence to Monckton Miles, 1863

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

Date: 26 Feb 90 17:17:43 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Subject: Re: Did SEASAT See More Than It Was Supposed To?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Nick Watkins) writes:
>as implausible that it could stay secret for over a decade, especially
>since I don't think DoD has any "prerogative" over civilian research
>satellites.
Jonathan McDowell has pointed out to me that the DoD sponsored the Geosat ERM
(exact repeat mission) which repeated some of the measurements, so the
"murder" theory seems pretty unlikely.

Nick


--
Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]

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

Date: 28 Feb 90 07:26:04 GMT
From: mailrus!b-tech!kitenet![e-mail]  (Russ Cage)
Subject: Re: Beanpole

In article <[e-mail]> [e-mail] (Richard Johnson) writes:
>>  An interesting idea I heard about but have no references for.
>>A sat is placed in LEO with a long, conducting tether extending upwards
>>from it.  A current is run through the tether, the Earth's magnetic
>>field interacts with it, and the sat raised into a higher orbit.
>>Cheap and efficient, but very slow.
>
>That idea showed up as a plot device in a SF story in Analog a few years
>back.  I think the author picked it up from a Space Studies Institute report
>on Space Shuttle External Tanks, which probably picked it up from somewhere
>else.

The story is "Tank Farm Dynamo", by David Brin.  It also appears
in the collection "The River of Time".  I recommend it.

The idea of an electrodynamic tether (using a tide-locked conductor
as the armature of a homopolar motor, with the earth providing the
stator field and the near-earth plasma the return path) is about 15
years old.  I own (but do not have handy, it's on loan) the
proceedings of the 1986 conference on tethers in space, which has
lots of neat details of the research done so far.  In short, it
appears that tethers system can provide:

1.)    Energy storage (motor/generator much more powerful than batteries)
2.)    Orbital reboost (byproduct of energy storage operation)
3.)    Emergency power generation (tap orbital motion for power)
4.)    Momentum/energy loans or transfers (not an electrodynamic effect)

all of which can be very useful to a space station or LEO habitat,
or the experiments done from one.  For example, dropping a Shuttle
orbiter on a tether from a space station raises the orbit of the
station, giving it angular momentum and energy.  This can extend
the interval between reboosts, provide energy to be tapped with
the tether-generator, allow satellites to be launched to higher
orbits via tether without dropping too far, etc. etc.
--
  I am paid to write all of RSI's opinions.  Want me to write some for you?
[phone]        Forewarned is half an octopus.
Russ Cage, Robust Software Inc.            [e-mail]

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

End of SPACE Digest V11 #99
*******************