Message-ID: <UcAqoG600WBw1D=05e@andrew.cmu.edu>
Precedence: junk
Reply-To: space+@Andrew.CMU.EDU
From: space-request+@Andrew.CMU.EDU
To: space+@Andrew.CMU.EDU
Date: Fri, 17 May 91 01:41:38 -0400 (EDT)
Subject: SPACE Digest V13 #563

SPACE Digest                                     Volume 13 : Issue 563

Today's Topics:
		       Re: Saturn V and the ALS
		       Re: Saturn V and the ALS
		       Space Station Cancelled
		     Should Galileo be rerouted?
		      Re: SPACE Digest V13 #533
		      Re: Why the space station?

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  space+@andrew.cmu.edu.  Other mail, esp. [un]subscription requests,
  should be sent to space-request+@andrew.cmu.edu, or, if urgent, to
			 tm2b+@andrew.cmu.edu

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

Date: 15 May 91 20:46:33 GMT
From: usc!zaphod.mps.ohio-state.edu!sdd.hp.com!news.cs.indiana.edu!widener!hela!aws@ucsd.edu  (Allen W. Sherzer)
Subject: Re: Saturn V and the ALS

In article <00948991.E9BFC720@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:

>Duh, huhhhh? We're going to build *TWO* new, improved lift vehicles, buy and
>Americanize a Soyuz and mount it on top of a U.S. booster (either? Both? You
>don't say up there) OR rebuild a CSM and certify it atop New, Improved
>boosters (two separate steps there), and then put up an Econo-lodge space
>"station" for the low-low-low price of one year's Shuttle costs? 

Yep. Costs are:

1. Develop two HLV's:                $1 billion
2. Integrate Soyuz with new
   vehicle:                          $1 billion (should be less than this)
3. Build econo-lodge station:        $2 billion (I'm splurging here as well)
                              total: $4 billion

Which is a lot less than a years Shuttle costs.

>You forgot the Ginzu steak knives. 

Fine. I'll toss in another billion for Ginzu steak knives and I'm still
spending less than a years Shuttle costs.

>Oh? So how do you fit SpaceLab modules on top of a Titan V and then bring them
>back in 7, 10, or 30 days? 

Titan IV is compatable with the Shuttle so it should go up with no problems.
As to bringing it back down, let's not. Let's keep it up there so it can do
more experiments.

>What do you propose to tell the European Community?
>"Sorry, folks, redesign again because we are..." How do you bring back
>satellites and haul around 7 people at once? How do you provide a robot arm and
>experiments in tethered satellites? 

At the moment there is no need to bring back satellites. Any satellite
you can name should be either repaired in space or tossed. None are worth
bringing back and relaunching at Shuttle costs.

As to transport to Freedom, you just use multiple Soyuz and on the HLV
and launch as needed. Still a lot cheaper than the Shuttle.

>How do you tell all the poor bastards who have based their graduate research
>work to fit into a Shuttle bay that they have to rework their experiements Yet
>Again? 

I will say: Good news! Your experiments will still work since the Titan
fairing is compatable with the Shuttle. Not only that, you will have an
order of magnitude more chances to do experiments since we now have a
station.

I think they can live with that.

    Allen
-- 
+---------------------------------------------------------------------------+
|Allen W. Sherzer |        Allen's tactics are too tricky to deal with      |
|   aws@iti.org   |             -- Harel Barzilai                           |
+---------------------------------------------------------------------------+

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

Date: 15 May 91 20:59:30 GMT
From: iggy.GW.Vitalink.COM!widener!hela!aws@lll-winken.llnl.gov  (Allen W. Sherzer)
Subject: Re: Saturn V and the ALS

In article <1991May15.203356.3913@agate.berkeley.edu> fcrary@lightning.Berkeley.EDU (Frank Crary) writes:

>>go to McDonnell Douglas and Martin and tell them: "OK, go ahead". We
>>could end up saving 90+% of the NLDP development costs. On the downside,
>>we will add maybe 5% to NLDP cost if it fails. Isn't that worth the
>>risk?

>I'm not sure that Martin or Douglas could come through... My point was
>that neither company expected the governemt to give an "OK, go ahead" sort
>of answer. 

I disagree. The effort began as a need to solve a very real and pressing
problem. SDIO had a 100K pound payload which they HAD to get to LEO to
test.

If this was a case where SDIO was blue skying and just asked for ideas
then you might be correct. However, they had a billion dollar program
which literally couldn't get off the ground. There was a genuine
mission which had to be met.

>But, hell, we might as well
>see if they could... If their numbers ARE right, it would be worth it.
>And if their price is off (and they know it) they get to look stupid.

That's all I am asking. Write your congresscritter and tell him/her.

  Allen
-- 
+---------------------------------------------------------------------------+
|Allen W. Sherzer |        Allen's tactics are too tricky to deal with      |
|   aws@iti.org   |             -- Harel Barzilai                           |
+---------------------------------------------------------------------------+

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

Date: Wed, 15 May 91 15:56:43 PDT
From: jim@pnet01.cts.com (Jim Bowery)
To: crash!space+@andrew.cmu.edu
Subject: Space Station Cancelled

The VA, HUD and Independent Agencies Subcommittee of the House
Appropriations Committee canceled Space Station Freedom at around
the end of business (4pm or so) today (5/15/91).
-----------------------------------------------------------------------------
Jim Bowery      619/295-3164               The Coalition for
PO Box 1981                                   Science and
La Jolla, CA 92038                             Commerce
-----------------------------------------------------------------------------

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

Date: 16 May 91 00:14:20 GMT
From: swrinde!sdd.hp.com!wuarchive!rex!uflorida!mailer.cc.fsu.edu!prism!ccoprmd@ucsd.edu  (Matthew DeLuca)
Subject: Should Galileo be rerouted?

In article <9105152035.AA25978@ucbvax.Berkeley.EDU> space+%ANDREW.CMU.EDU@msu.edu writes:
(In reply to me, ccoprmd@prism.gatech.edu:)

>Yes, more flybys would give us more information.  Galileo is currently slated
>to take a look at TWO big rocks.  What if they happen to be just rock?  No
>volatiles, no metals, mo water, etc.

What if the dozen or so rocks that Galileo could attempt to peer at were  
also just rocks?  If the first two are useless rocks, what makes you think
the next dozen are going to be any better?  Instead of gambling that later
rocks will be better than the first couple, why not see the first couple, 
go on to Jupiter, and get all the knowledge we can find there?  There's 
dozens of different things going on at Jupiter that we got glimpses of 
with the Voyager spacecraft...why throw all that knowledge away for a mission
that will result in almost zero net knowledge?

>So NASA decides that the 'stroids are worthless, while hundreds of 'stroids,
>none of which we look at, are just aching to be mined?  Sure, we don't know.
>My point is that we may never know!

What do you think CRAF (Comet Rendezvous and Asteroid Flyby) is for?  CRAF 
will be optimized for the task of looking at asteroids, as opposed to 
Galileo, which is going to turn instruments designed for other purposes 
to the task of looking at rocks as a sideshow?

>Galileo could easily look at THOUSANDS of rocks.  All different sizes, and
>compositions.  Much better data for making any decision.

I wouldn't bet on more than a dozen asteroid flybys, tops.  Remember, 
the asteroid belt isn't a flying ring of packed rocks...the individual
asteroids are separated by thousands and hundreds of thousands of miles, 
over millions and millions of cubic miles of space.  Add to that the 
fact that you are pretty much going to be flying simple elliptical orbits
with only minor nudges from the rockets on board, and you are looking
at months between asteroid encounters...and Galileo won't live forever.

>If galieo is broke, then it already has been diverted from the mission it was
>designed to do.  Why not change the mission?

Because the mission can likely be salvaged.  The antenna may yet deploy, 
or they can send the relay satellite out to Jupiter on a fast orbit.  The 
knowledge waiting for us at Jupiter is worth it.

>>You will *still* have to have an analysis done by a penetrator
>>mission before you send anyone or anything out there to exploit them, so
>>why waste our time now?  Do it right.

>But, we would still need someone with some kind of power to want to send that
>penetrator mission.  Galileo could convince that person/agency to do it!

Assuming CRAF still has its penetrator on board, (I heard it was having 
budgetary problems a while back) CRAF will do exactly what is needed to
help us start understanding what resources are out there.  Galileo will
not.

>Seriously, here's my perspective;
>Given:  We don't know what's at either place.

Not exactly.  We suspect liquid water on one Jovian moon, we know extensive
vulcanism is occurring on another, the two other Galilean moons are also
somewhat interesting, there's nifty tidal and plasma interactions going on 
out there, there's the whole atmosphere of Jupiter to think about, plus 
whatever else we can find.

We have some idea of what asteroids are composed of, from spectral data
and pieces that have come to earth.  Galileo can add some more spectral 
data, perhaps slightly better than what we have now.  CRAF will (likely)
render that data obsolete in a few more years.

>Given:  If there were equal resource abundances at both places, the 'stroids
>        would be better.  (delta-vee, travel time, gravity well, etc)

Probably so.  Too bad we're nowhere near the ability to exploit asteroids.

>MY conclusion;  Blow Jupiter 'till we know what's at the 'stroids;  I think
>at this point in time, science for it's own sake should take a back seat to
>science for maximization of resources.

Again, we aren't in a position to exploit asteroids in the interval between
Galileo and CRAF, so why are you wanting to abandon all the knowledge we
can gain at Jupiter for obsolescent data on asteroids?

>I'm not suggesting setting up multi-$$ operations.  I'm suggesting that IF
>Galileo is broken, It's value could be increased by altering it's goals.

But the goal you are thinking of won't do that...
-- 
Matthew DeLuca                   
Georgia Institute of Technology      "I'd hire the Dorsai, if I knew their
Office of Information Technology      P.O. box."  - Zebadiah Carter,
Internet: ccoprmd@prism.gatech.edu    _The Number of the Beast_

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

Date: 15 May 91 04:52:20 GMT
From: elroy.jpl.nasa.gov!swrinde!zaphod.mps.ohio-state.edu!wuarchive!emory!wa4mei!ke4zv!gary@lll-winken.llnl.gov  (Gary Coffman)
Subject: Re: SPACE Digest V13 #533

In article <9105140151.AA14702@ucbvax.Berkeley.EDU> space+%ANDREW.CMU.EDU@msu.edu writes:
>Subject: Re: SPACE Digest V13 #486
>
>>In article <9105012254.AA13665@ucbvax.Berkeley.EDU>
>> space+%ANDREW.CMU.EDU@msu.edu (someone who hides his name behind
>> a gateway) apologizes for Coffman's errors:
>
>>reference work, nor address all the physical and engineering
>>problems of laser-launch systems.  If you demand that I do,
>>I will politely tell you to get lost.
>
>You are doing much better here!  You actually gave some useful information!
>Good.
>Unfortunatley, I did not stress that the information I was seeking was the
>solution to the blooming problem.  This was one of the things you originally
>blasted me (and coffman) for suggesting exists.  The answer had NOT been posted
>to this group many times (I've never seem it anyway.)
>
>That you so easily brush it off (get lost?) suggests that your initial
>assertion that it's easily solvable or non-existent is either too obvious to
>mention (doubtable) or you don't know.  Should I blast YOU for being ignorant?

Exactly my point. Blooming, actually opaque plasma blocking, *seems* to be
a stopper for laser launchers. I've seen nothing to suggest that the problem
has been addressed or solved at the power levels required. Sure, I've seen
demonstrations of CO2 lasers burning holes in steel plates, but that's orders
of magnitude less energy than would be needed at the rear of a laser launched
vehicle. When the beam power density gets high enough, the air breaks down
into a plasma causing opaque plasma blocking. This wasn't appreciated until
really high beam densities became available with the advent of actual laser
fusion experiments. This knowledge seems to have percolated over into the
SDI field since I've seen an apparant abandonment of ground based lasers
as part of the missile defense proposals. At least it has dropped from the
open literature. If laser launchers were really viable, that same energy
density laser would seem to be a cost effective missile defense. That it
has apparantly been abandoned, says a lot to me.

>point shows how useless tactlessness is in 'educating' someone.  I'm sure that
>your snide comments to Coffman brought him no closer to learning about either
>rocketry or laser-launch (which, it seems to me, you would like people to
>learn about, since it seems promising).  Similalry, my snide comments to you
>will probably bring you no closer to a professional manner, though your
>previous paragraph containing actual math suggests that you have the ability
>to learn, though I wouldn't have the patience, either.

Actually, his snide comments caused me to go do some reading, prompted some
kind people to email me some useful material, and actually solidified my
previous belief that laser launching faces some daunting problems.

>Back to the original point regarding rocketry and 'efficiency':  When Coffman
>suggested that the advantage to a rocket is that more of it's fuel goes into
>lifting payload, rather than fuel, as time goes on, why didn't you point out
>that a Laser Launcher gets the same advantage, since more of it's energy goes
>into lifting payload rather than reaction mass as the flight progresses?

Yeah, I really blew this one. It's obvious when you point it out. It doesn't
seem to effect my main point that delivering energy from a distance rather
than deriving it directly from the reaction mass (fuel) pays an energy 
efficiency penalty. That the penalty may be offset by using a block of
ice to make up the bulk of the vehicle, a kind of caseless cartridge, hadn't
been brought out at that point either. That's very ingenious. Whether
guidance could really be done by precise off center heating, or whether
laser pulses of sufficient power to cause explosive vaporization can be
delivered to the target vehicle still seems the sticking point. As Orion
showed, explosions can power a vehicle, but their design carried the 
explosives with them rather than attempting to push the energy through
the atmosphere from the ground with a beam of light.

Gary

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

Date: 15 May 91 16:32:23 GMT
From: swrinde!cs.utexas.edu!news-server.csri.toronto.edu!utzoo!henry@ucsd.edu  (Henry Spencer)
Subject: Re: Why the space station?

In article <1991May15.043205.20590@sequent.com> szabo@sequent.com writes:
>Returning Martian polar samples wouldn't require any sort of assembly.
>You would land a small drilling rig on the pole...  return to earth
>via rendesvous and sample transfer in Martian orbit.  The lander/drilling
>rig is all one piece, the orbiter is a separate peice.  There is no
>benefit from assembly...

Except that the mission is too big for existing boosters.  Especially if
you exclude all the untried technologies involved in that "rendezvous and
sample transfer in Martian orbit".  And especially if you remember that
you're never going to get funding to fly more than one of these, so it
has to include some way of getting samples from all the *other* places
people want samples from.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry

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

End of SPACE Digest V13 #563
*******************