Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO394.TXT

Internet Message Format | 1993-07-13 | 27KB

Date: Wed, 31 Mar 93 05:10:27
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #394
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 31 Mar 93       Volume 16 : Issue 394

Today's Topics:
                            >19 km tether
   Aerospace in Dallas (was Re: Why use AC at 20kHz for SSF power)
                  Alaska Pipeline and Space Station!
                    Atlas rocket question (3 msgs)
                 COPOUS & the privatization of space
             DC-X: Pratt Ships Final Test Engine (2 msgs)
   First Mission  of the Small Expendable Deployer System SUCCESS!
                Gemini 8 (was Re: Artificial Gravity)
               Mars Observer Update - 03/29/93 (2 msgs)
                            nuclear waste
                      Question on Cassini Radar
                             Sorry folks!
                     SSF Redesign (and Gimballs)
           the call to space (was Re: Clueless Szaboisms )
                    Why is Venus so bad? (2 msgs)
                  Why use AC at 20kHz for SSF power

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

Date: 30 Mar 93 23:05:00 GMT
From: [e-mail]
Subject: >19 km tether
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (CLAUDIO OLIVEIRA EGALON) writes...
>Few minutes ago I was at the canteen here in my building and someone
>posted a message in there commemorating a new world record on
>tether deployment (because of this record they would be paying today's
> coffee). They might be refering to SEDS and the distance claimed
> was more than 19 km. The date posted was today's 03-30-93.
>
>Does anyone in the NET have any further details on that???
>
>[e-mail]
>

What you heard is correct. Last night's Delta II/GPS/SEDS mission that
deployed the 20 km of tether is the new world record. TSS only deployed
681 feet (meters?) of tether during STS-46. This tether is made of spectra
1000, a long chain polymer that is stronger than kevlar in tension.  Also it
has very low friction, which has been the biggest bugabo of doing tether
deployments.

The end mass was built in house at Langely.  This is probably where you got
your information today. We here at UAH hope to get the data from the
end mass and the SEDS deployer soon for us to do an animation of the
deployment.

Congratulations to NASA Marshall and to Langley for pulling of a great mission.

Dennis, University of Alabama in Huntsville

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

Date: 30 Mar 93 20:52:19 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Aerospace in Dallas (was Re: Why use AC at 20kHz for SSF power)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:

>> [a lot of aircraft built in Dallas]

>Well, I'd agree with all but that last bit.  We don't do that many
>airplanes in Dallas, I don't think.  Now, if you want to go over by Ft
>Worth . . .

LTV Aircraft Products Group is in Dallas and they make large sections of
many commercial and military airliners. If you want to go into related
products you have your employer (TI) and Collins make avionics and radars
and E-Systems (along with a few smaller companies) making ECM and other
EW systems. There is also American Airlines providing extensive training
and simulation facilities. There are also a few small companies at
Love Field doing airliner maintenance and refurbishment.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------78 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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

Date: 30 Mar 1993 14:32:01 -0500
From: Pat <[e-mail]>
Subject: Alaska Pipeline and Space Station!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>The US government historically has been most unwilling to just set the
>performance specs and guarantee the market for spaceflight.  (It's been
>done with enormous success in other areas, notably aviation.)  NASA and


I can think of Airmail,  but what else?


pat

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

Date: 30 Mar 1993 13:58:00 -0500
From: Pat <[e-mail]>
Subject: Atlas rocket question
Newsgroups: sci.space

A question is asked about the configuration of an atlas.

Arentt those Boost engines?  THey  help at liftoff and get dropped?

I read in this weeks news, that the ATLAS-Centaur for UFO-NAVY
Dropped into a bad orbit due to a failure in these engines.

They apparently burned at only 65% power, consuming fuel at too high
a rate.   The centaur corrected some for the failure,  but UFO
is now sitting in an orbit with too low an apogee.

GD is apparently in some trouble given this is their third failure
in 1 year?

pat

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

Date: Tue, 30 Mar 1993 20:57:04 GMT
From: Glenn Serre <[e-mail]>
Subject: Atlas rocket question
Newsgroups: sci.space

   Arentt those Boost engines?  THey  help at liftoff and get dropped?

I think the question was actually about the vernier rockets (I don't know the
official Atlas terminology) used to provide stabilization.

--Glenn Serre
[e-mail]
--

--Glenn S. (gaserre)

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

Date: Tue, 30 Mar 1993 21:02:44 GMT
From: [e-mail]
Subject: Atlas rocket question
Newsgroups: sci.space

In article <1pa57o$[e-mail]>, [e-mail] (Pat) writes:
|>Path:
|
dbased.nuo.dec.com!news.crl.dec.com!deccrl!decwrl!ames!olivea!uunet!digex.com!
!digex.com!not-for-mail
|>From: [e-mail] (Pat)
|>Newsgroups: sci.space
|>Subject: Re: Atlas rocket question
|>Message-ID: <1pa57o$[e-mail]>
|>Date: 30 Mar 93 18:58:00 GMT
|>References: <[e-mail]>
|>Organization: Express Access Online Communications USA
|>Lines: 15
|>NNTP-Posting-Host: access.digex.com
|>
|>A question is asked about the configuration of an atlas.
|>
|>Arentt those Boost engines?  THey  help at liftoff and get dropped?

The question was about the little flames shooting out at an angle.  Those are
called "verniers" and are used to stabilize and stear.  They don't provide much
thrust as such things go.

|>I read in this weeks news, that the ATLAS-Centaur for UFO-NAVY
|>Dropped into a bad orbit due to a failure in these engines.
|>
|>They apparently burned at only 65% power, consuming fuel at too high
|>a rate.   The centaur corrected some for the failure,  but UFO
|>is now sitting in an orbit with too low an apogee.
|>

I never saw anything about what the problem was with the recent Atlas-Centaur
failure, but the Atlas is a rather odd beast in that it has a single engine in
the middle called a sustainer which starts before liftoff and runs all the way
to orbit (or till the end of Atlas-powered flight, anyway).  Then there is
an engine on either side of the sustainer which burns for only the beginning of
the flight.  Then these engines are jettisoned to save weight.  That may be
what
you are talking about.

Yes, I imagine McD-D is probably really concerned now, though the previous two
failures were in the Centaur, not the Atlas.

Burns

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

Date: 30 Mar 93 22:48:38 GMT
From: Nick Szabo <[e-mail]>
Subject: COPOUS & the privatization of space
Newsgroups: sci.space,talk.politics.space

[e-mail] (M. Sean Bennett) writes:

>The Moon, Mars, etc. are "claimed for all mankind".

COPOUS wording is a massive goldmine of silly platitudes such
as this.  The moon at that point was pretty worthless except
for the anti-communist PR stunt Apollo to shore up our
technological reputation (our == U.S.).  But we did have major
concerns elsewhere in space.

As Heinlein pointed out in "The Man Who Sold the Moon", written
in the 1940's, national and private real estate claims have always
theoretically extended upwards to infinity.  In Heinlein's story the
robber baron hero goes to great lengths to get the equatorial states
to claim the moon and sell him their claims.  In real life, the U.S.
couldn't just start launching satellites over Soviet territory to spy on
them -- a clear violation of airspace according to then existing
precedents.  The real point of all that "common heritage" stuff
was to get the U.N. to set up something like the freedom of the
seas, so we could fly our spysats over the U.S.S.R. without getting
them shot down at worst, or getting shouted down as an international
criminal at best.  For similar reasons, Eisenhower stopped Von Braun
from launching before Sputnik, something Von Braun fans have ignorantly
griped about ever since.  A military flight would given the Soviets
leverage to prevent deployment of the much-needed spysats, a "pure
science" flight or, even better, a Soviet first set a precedent that
air space & national claims stop above the stratosphere.

Nevertheless, our inferiority complex over Sputnik was severe enough it
probably cost the Republicans bigtime in elections throughout the 1960's.
Ike was a smart diplomat and a dumb politician, like Bush.

For industry, we need to make similarly creative if somewhat
different interpretations of the vague wording in COPOUS et. al.
Last I checked, U.S. & Europe had divied up (and spent the
$$$ to develop) most of Clarke orbit, real estate now worth over
$10 billion, with only trivial concessions to the equatorial countries,
despite all the "common heritage" pretensions.  The trick now is
to transition Clarke allocations, both orbit slots and
frequencies, from bureacratic regimes (Intelsat, WARC, etc.)
to private property.  Once we solve the Clarke orbit mess,
other space real estate issues look easy by comparison, though
there's still room for fun disputes & interesting new forms
of property (eg "the 2010 launch window to P/Encke").


--
Nick Szabo                     [e-mail]

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

Date: 30 Mar 93 20:04:11 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: DC-X: Pratt Ships Final Test Engine
Newsgroups: sci.space

In article <1pa6iu$[e-mail]> [e-mail] (Pat) writes:

>What I found interesting was how small the engines are.
>They are about man sized, which will certainly simplify
>handling procedures.

Note that the RL-10 is NOT what DC-Y will use. The DC-Y engines
(tenataively called the RL-200) will provide about 10 times as
much thrust.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------78 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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

Date: 30 Mar 1993 14:21:02 -0500
From: Pat <[e-mail]>
Subject: DC-X: Pratt Ships Final Test Engine
Newsgroups: sci.space

What I found interesting was how small the engines are.
They are about man sized, which will certainly simplify
handling procedures.

pat

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

Date: 30 Mar 93 09:19:46 GMT
From: Pat <[e-mail]>
Subject: First Mission  of the Small Expendable Deployer System SUCCESS!
Newsgroups: sci.space

Dennis

    What were the areas of Risk in SEDSat ?

The tether was pretty much well known material,  the deployyer you showed
me makes my fishing reel look complex.  I'd guess the control
and electronic sensors were mostly out of the box.

THe big risk factor to me was how the system would actually behave,
wether odd effects would show up.

Simplicity is a virtue.

pat

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

Date: 30 Mar 93 09:06:10 GMT
From: Pat <[e-mail]>
Subject: Gemini 8 (was Re: Artificial Gravity)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Chris Jones) writes:
>of fuel left when Armstrong set it down on the moon.  (What was it with
>Armstrong, anyway?  He also had to eject from an LLRV when rehearsing a lunar
>landing.)

From my understanding,  The LLRV had some sort of delay in the
control mechanism.  Armstrong found that out the hard way.

pat

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

Date: 30 Mar 1993 19:01 UT
From: Ron Baalke <[e-mail]>
Subject: Mars Observer Update - 03/29/93
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <1p7fqc$[e-mail]>, [e-mail] (Pat) writes...
>In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>|
>|     Surplus fuel reserves from good launch conditions will allow
>|ground controllers to use more propellent after Mars orbit
>|insertion (on Aug. 24, 1993) and drop the spacecraft more rapidly
>|into its low-altitude mapping orbit. Consequently, science
>|operations will start 21 days ahead of schedule, beginning on
>|Nov. 22, 1993, rather than Dec. 12, 1993.
>|
>MY understanding is the Power in is being done because they used less
>fuel then planned during the Mid course Burns.

The Power-In option is available because the launch trajectory was
so accurate, less fuel was used at the subsequent TCM's.  The next
TCM may even be cancelled.

>Now what SPace NEws said, is that they are concerned about instrument
>failure while waiting for the Dust to settle.   Is this true?
>Are they really concerned about instrument failure?

There is no concern for instrument failure, the science team just wants
to get started as soon as possible.  There are two periods next year where

science data collection will be suspended or minimal: during the solar
conjuction period in December/January, and during the Mars dust storm
season that runs roughly from February to August.

>And if that is the case, could they have planned the mission to avoid the
>dust season?

Predicting dust storms on Mars isn't an exact science.  The bigger
contraint is the launch window to Mars which occurs about every two years.

>ALso,  it seems to me, that fuel is a real precious
>resource.  After the mapping is done,  reserve fuel could
>be saved for  orbit changes,  or to improve mapping of the moons phobos
>and deimos.

There will still be enough fuel for an extended mission after the primary
mission ends in 1995.  This assumes though that the spacecraft won't be
turned off due to lack of funding.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Don't ever take a fence
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | down until you know the
|_____|/  |_|/       |_____|/                     | reason it was put up.

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

Date: 30 Mar 1993 13:52:58 -0500
From: Pat <[e-mail]>
Subject: Mars Observer Update - 03/29/93
Newsgroups: sci.space,sci.astro,alt.sci.planetary

It was in last weeks SPace News of AW&ST  that they talked about
reasons for speeding up "Power IN"  trajectory.

Look in the library.

I don't know the dates off hand.


Steve makes the point that even if you have spare fuel, it's
not much good, once the science booms are deployed.

Are the boom deployers,  just one way?  That is there is no way to pull the booms
back in after a  while to make a big burn on the bi-prop system?

Second once major science goals have been achieved, it may be worth
contaminating  a few instruments in favor  of a new orbit.

Now MO won't be dropping her orbit.  My understanding is Planetary
protection guidelines put her into ahigh orbit.  But If nothing else
the spare mass of fuel helps keep the bird stable and improve orbital lifetime.

pat

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

Date: 30 Mar 93 19:43:09 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: nuclear waste
Newsgroups: sci.space

[e-mail] (William Reiken) writes:

>In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
>>
>>(1) The total requirement for isotopes for those missions is measured
>>        in kilograms.  While the hazardous-waste output of nuclear power
>>        plants *is* miniscule compared to that from fossil-fuel plants,
>>        it's not *that* miniscule.
>>
>> (2) They need isotopes with relatively short half-lives and little or no
>>        gamma emission, so they get a lot of power output in a form that
>>        is easily converted to heat.
>>


>    It has been proposed that by using SDI designed particle accelerators
>that most of the waste could be tranmutated to more useable forms.  Why not
>build a few proccessing plants to do this?

Uh, maybe in Japan this would be feasible. You could buy the particle
accelerators from us, and the accelerator guys would have something to
do;

Will, it's been illegal since the '70's to reprocess/recycle nuclear
fuel in the US. You can't remove the fission fragments from the fuel
rods, so that they have to be thrown into a waste storage facility
while they're still 98% good. This way, there's a major waste problem,
that you can use as an excuse to shut the whole industry down.
(I mean, what sort of place is the US if it requires by law that
90+% of usable uranium be thrown away, and then declare that there
is no legal place to throw it away, and finally state that until there
is, no more nuclear plants!)

(NOW do you see what I meant when I said that Arab "economic conquest"
a much greater threat to the US and Japan than Japanese "economic
conquest" of the US?)

>    A Question:  Has oil been found anywhere eles in our Solar System
>        in the raw form that we dig it up in here on earth?

I think something shale-like has been found.

>    If not, we may be in for some problems later.

Why?

>                    Will...


--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: 30 Mar 93 19:53:47 GMT
From: David Seal <[e-mail]>
Subject: Question on Cassini Radar
Newsgroups: sci.space

[e-mail] (Bill Higgins-- Beam Jockey) writes:

>In article <[e-mail]>, [e-mail] (Schroder S) writes:
>> This is a request for more information about the Cassini radar.

>I wonder whether they have any plans to point it at Saturn.  Would it
>show anything?  And will they use the radar on other satellites which
>are not cloudy?

That's a neat question.  For now we are not planning to point it at anything
except Titan.  The orbit period(s) are designed to by synchronous with Titan's
(i.e. n orbits of the spacecraft with every m orbits of Titan, where n and m
are integers, usually) so targeted icy satellite flybys are much less numerous.
We have a requirement to provide at least four, and have a number of nontargeted
encounters, but those are easily too far away to provide good radar data.  And
since the targeted icy satellite flybys are so few, we will be doing remote
sensing during that period.

>You are correct.  The SAR will scan only a few skinny little strips of
>Titan's surface.  Cassini will not orbit Titan, so the radar can only
>be used on a few occasions when its Kronian orbit (I saw this word in an
>astronomy paper the other day, I couldn't wait to use it) brings it
>close to Titan.  It will still be better than pictures of a
>featureless orange tennis ball!

There's some speculation that we might be able to see down to Titan's surface
with the remote sensing instruments, as well as with radar.  The Voyager images
were confined to relatively narrow frequencies, and it's possible that the
surface might be visible at others.  We all hope we get a lot better than the
tennis ball we have now.

Dave Seal
Cassini Mission Design
--
-----------------------------------------------------------------------------
David Seal                 |  Jet Propulsion Laboratory  |     sunset: 7:54pm
[e-mail] |       Mission Design        |   temp: 82 degrees

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

Date: Sun, 28 Mar 1993 12:14:07 +0000
From: Paul Wilson <[e-mail]>
Subject: Sorry folks!
Newsgroups: sci.space

I'd like to apologise for posting my objection to the (in)famous Soviet
Starwars article.  I had intended to mail the damn thing,  but either
dyslexia or finger trouble hit me.

I'll try harder next time.

Paul

------------------------------< Who 'zat? >------------------------------
    Paul Wilson, P-and-S Ltd, P O Box 54, Macclesfield, SK10 5EH, UK
     [Email: [e-mail]]  [Phone: +44 (0) 625 - 503150]
-------------------------------------------------------------------------

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

Date: 30 Mar 1993 14:28:22 -0500
From: Pat <[e-mail]>
Subject: SSF Redesign (and Gimballs)
Newsgroups: sci.space

I figured you needed to keep the Beta gimbels,  and after all,
lots of spcecraft use them.

I just wasn't sure about the alpha gimbels.  AS you point out Gravity Gradient
mode  solves the earth point problem,  at a cost to  drag,  or Arrow mode
also  seems to work,  at a cost to increased roll requirements.Now would
this pitch come from  gyros  or would you also need to burn hydrazine.

My thinking was that without the alpha gimbels,  you have a lot more room
to work on the truss,  and  you simplify a lots of problems.
Scan platforms are more complex then gimbels,  but we know these problems.

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

Date: 30 Mar 1993 13:23:22 -0500
From: Pat <[e-mail]>
Subject: the call to space (was Re: Clueless Szaboisms )
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <1ot012$[e-mail]> [e-mail] (Pat) writes:
>
>Ask him about the lifetime of his power plants.  They don't last forever.
>They're all going to have to be replaced, many of them within our lifetimes.
>Reducing load helps, to be sure, but it has limits.

Well, Life extension programs are still  a growing area,  and it's
still cheaper to replace a wornout plant  with a new plant then to
build a bigger plant  to meet additional demand and then have 2 plants
to replace down the line.

I never said you don't ever have to invest in new plant,  but that
you can save a lot of money by deferring that cost through conservation.
pat

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

Date: Tue, 30 Mar 1993 19:20:40 GMT
From: Oivind Toien <[e-mail]>
Subject: Why is Venus so bad?
Newsgroups: sci.space,rec.scuba

In article <[e-mail]> [e-mail] (Anthony DeBoer) writes:
> Frank Crary <[e-mail]> writes:
> >The extremely deep dives don't use anything close to a "normal" air
> >mixture: Instead of 20% oxygen/80% nitrogen, they use something like
> >1% oxygen/99% helium. An inert gas like helium avoids alot of the
> >problems of very high pressures (if you don't mind working with
> >Mickey Mouse and Donald Duck...)

> I've also heard tell of them using "hydrox", a hydrogen-oxygen mixture
> with such a low oxygen percentage that allegedly it won't support
> combustion.  It still has a high enough partial pressure of oxygen to
> support life, at those high pressures.  Apparently, even helium is too
> dense for those dives into the four-digit-depths.  There comes a point,
> however, when I must admit that anyone diving with this stuff is a braver
> man than me.
> --
> Anthony DeBoer  < [e-mail] | uunet!geac!herboid!adb | [e-mail] >
>  NAUI # Z8800, D5482

In a previous record dive (dry) at NUTEC, Bergen, Norway to about 500
m they used a Heliox mixture most of the time except during the descent
were the gas mixture contained some nitrogen. The idea was the the
effect of N2 narcosis should reduce the effect of high pressure nerve
syndrome.
Several of the divers suffered serious injury. Although technology
seems to develop infinitely, physiology sets certain limits...

In a program on the Norwegian channel 2 yesterday it was said that 1
of 7 divers are injured (per dive...) in dive operations in the North
Sea occuring at more than 300 m.

--
Oivind Toien  <[e-mail]>
Dept. of Arctic Biology, Institute of Medical Biology, University of Tromso
---------------------------------------------------------------------------
9037 Tromso, NORWAY                     Phone[phone]   Fax[phone]

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

Date: 30 Mar 93 21:01:21 GMT
From: "David (Duis" <[e-mail]>
Subject: Why is Venus so bad?
Newsgroups: sci.space,rec.scuba

In article <[e-mail]> [e-mail] (Anthony DeBoer) writes:
>
>Divers have been down to the vicinity of 2000' (approx. 60 atms, although
>my copy of Guiness with the exact number as of a few years ago is in a
>box packed away somewhere; I do remember that it was French
>commercial/military divers who set the record), though, which isn't quite
>100 atms, but is within an order of magnitude, so eventually I'm sure
>we'll see it done.

The latest world record was a dive to ~1100m done by a French
commercial diving company.  This was reported in the latest UHMS
Pressure.

Cheers,

David Story                        NAUI AI Z9588, PADI DM 43922, EMT
[e-mail]            Better diving through lithium.

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

Date: Tue, 30 Mar 1993 18:19:13 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: Why use AC at 20kHz for SSF power
Newsgroups: sci.space

In <[e-mail]> [e-mail] ("RWTMS2::MUNIZB") writes:

>On 23 Mar 1993 15:25:37 -0500, Pat <[e-mail]> writes:

>/PS.  Aviation is a fairly large segment of the US economy.  Larger
>/then you think.   Dallas, Wichita, Seattle and St Louis make
>/aircraft a substantial part of their business.

>Agreed.

Well, I'd agree with all but that last bit.  We don't do that many
airplanes in Dallas, I don't think.  Now, if you want to go over by Ft
Worth . . .

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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End of Space Digest Volume 16 : Issue 394
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