Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V13_3/V13_370.ZIP/V13_370

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Subject: SPACE Digest V13 #370

SPACE Digest                                     Volume 13 : Issue 370

Today's Topics:
            SPACE Digest V13 #358
            SPACE Digest V13 #364
             RE: Nuclear Rockets
        Re: comsat cancellations and lawsuits
 Re: New Improved Rail-Gun, now with Hotol for Added Pep and Verve...
        Re: comsat cancellations and lawsuits
           Galileo Status for 04/04/91 (Forwarded)
       Re: ESA's space science dept participates in GRO
     Re: Chemical rocket complexities (was Re: "Follies")
             Re: Laser launchers
            SPACE Digest V13 #362

Administrivia:

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ReSent-Message-ID: <[e-mail]>
Resent-Date:  Fri, 05 Apr 91 13:35:40 EST
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Resent-To: [e-mail]
Date:         Fri, 5 Apr 91 01:53:58 EST
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #358
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>


>HUGHES SUIT:
>It is about TIME someone sued the pants of NASA for breech of contract. They
>deserve to learn, just like anyone else, that when you sign a contract, you
>deliver. One of the reasons I would not deal with the US government (or any oth
  (short paragraph about the basics of contract law, which NASA has such a
   hard time following)

>As far as I'm concerned, NASA signed contracts and was bound to perform or
>pay. I agree that NASA should not have been in the business to start with, and
>that they should certainly have taken no new contracts after Challenger. But
>a professional would have realized that terminating existing contracts means
>you give the customer satisfaction for losses you cause him by reneging.

>I think it is just fine for them to be taught a good solid whacking EXPENSIVE
>lesson about business law.

I certainly agree that NASA should keep up their end of a contract.  But it
won't really teach them a lesson to take money from you and me, which is what
this plan would really mean.  Maybe if they were taught a JOB_COSTING lesson.

Of course, the advantage to the current system is that NASA will be out of the
launch business sooner, if no customers are willing to risk the costs  of a
scrub...

Tommy Mac
18084tm@msu
Acknowledge-To: <18084TM@MSU>

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Resent-Date:  Fri, 05 Apr 91 15:11:15 EST
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Date:         Fri, 5 Apr 91 02:50:59 EST
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #364
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

Re: E.T.'s

>> If you want to look for non-terrestrial life, current thought holds that the
>>most likely place to find it will be floating high in the atmosphere of
>>Jupiter.

>        Wonder what is going on in SETI right now?

Not looking at Jupiter.  They want Intelligent life, not the gas-bags, hawky-
like creatures or microbes that are thought could be in Jove's atmosphere.

Actually, I think they're trying to cope with three facts that make their task
almost intractable:

1) They don't know where a signal might come from, or where to send it to
2) They don't know what frequency it will be carried on (EM waves)
   Or whether it's AM or FM (or who knows what)
3) They have about .01% of the telescopes and antennas needed to overcome
   the first two problems, assuming they were all used for SETI, which they
   aren't.

My biggest problem with getting into SETI would be;  Suppose you find evidence
that there is life 3.5 million light years away;  So what?  What do you do now?

Another problem is;  What if the guys you find don't think of us as enemies, or
even potential slaves, but FOOD?  No thanks!

There is the argument, tho, that since we have now advertised our presence to
the surrounding 60 ly sphere in space (TV started in 1936), we should at least
find out if we are attracting unwanted attention that we should prepare for.

Tommy Mac
18084tm@msu
Acknowledge-To: <18084TM@MSU>

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

Date: 5 Apr 91 21:10:25 GMT
From: virga.rap.ucar.edu![e-mail]  (Frank Hage)
Subject: RE: Nuclear Rockets


    A naive question:

    If a nuclear rocket develops thrust by vaporizing liquid hydrogen
passing over (through?) the reactor core, and the hydrogen acts
as the coolant, what keeps the reactor from melting "before ignition"
and after the LH fuel has run out?

-Frank Hage.     National Center for Atmospheric Research.
[e-mail]

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

Date: 6 Apr 91 03:16:54 GMT
From: usc!rpi![e-mail]  (Michael V. Kent)
Subject: Re: comsat cancellations and lawsuits

In article <[e-mail]> [e-mail] writes:
>Considering passed performances and some questionable over charging, I'm
>not sure that Hughes or any other aerospace firm has a "right" to be ticked
>off.  Call it poetic justice.  This law suit, no matter who wins, is going to
>cost the U.S. taxpayer.  Since Henry is Canadian he doesn't have to worry,
>though. :-)

Hughes -- and any other firm for that matter -- has a right to be ticked off
anytime they are given a raw deal, whether it is by the U. S. government or
another private organization.  Although I would not like to see space
exploration reduced because of such a lawsuit, it might be worth it if the
U. S. government starts respecting its own law.

Michael Kent                                         [e-mail]

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

Date: 5 Apr 91 20:05:34 GMT
From: swrinde!cs.utexas.edu!titan![e-mail]  (Donald Heskett)
Subject: Re: New Improved Rail-Gun, now with Hotol for Added Pep and Verve...


>Out of interest, what size of craft (shell/bullet/blob) are rail-guns being
>designed for firing? What's the chance of being able to track them accurately
>enough to combine rail & laser/ice propulsion?
>_________________________________________________________________
>Mike Salmon, Climatic Research Unit    | "Spin, spin, spin the
>Univ. of East Anglia, Norwich, England |  Wheel of Justice..."
>[e-mail]   [phone] |

What is "laser/ice propulsion"?

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

Date: 5 Apr 91 21:06:36 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!uupsi!pbs.org![e-mail]
Subject: Re: comsat cancellations and lawsuits

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:

> Hughes is not suing over the decision to take comsats off the shuttle; it
> is suing over the government's refusal to compensate innocent customers for
> the financial losses they incurred when the government broke its promises.

By the way, just what financial losses are we talking about?  Sure it cost more
to launch aboard the Arianes than Hughes had been promised for the shuttle, but
if Hughes did not have customers lined up, it wouldn't have launched the birds
period.  I suspect they have made up any "losses" by passing them on to the end
users.

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

Date: 6 Apr 91 00:28:20 GMT
From: [e-mail]  (Peter E. Yee)
Subject: Galileo Status for 04/04/91 (Forwarded)


                      GALILEO STATUS REPORT
                          April 4, 1991

          Operations are proceeding smoothly to bring Galileo out
of safing mode, flight controllers report.

          The spacecraft entered safing mode Tuesday, March 26,
after an unexpected transient signal caused one of Galileo's two
redundant Command & Data Subsystem computers to detect an error
in itself.  In safing mode, Galileo turns off science
instruments, changes its spin configuration, slows the bit rate
of data it sends to Earth and automatically performs maneuvers on
a regular basis to orient itself to the Sun.  The spacecraft
responded exactly as intended, the flight team noted.

          Project officials said they plan to bring the
spacecraft out of safing mode gradually so that it is ready to
execute the next major sequence of commands to be sent to Galileo
on April 25.

          Current plans call for Galileo to unfurl its high-gain
antenna on Thursday, April 11.

          Today Galileo is 37 million miles from Earth and 119
million miles from the Sun, traveling at a heliocentric speed of
64,400 miles per hour.  Round-time communication time is 6
minutes, 33 seconds.

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

Date: 5 Apr 91 16:07:37 GMT
From: usc!sdd.hp.com!spool.mu.edu!cs.umn.edu!ariel.unm.edu!nmsu!charon![e-mail]  (Bill Webber)
Subject: Re: ESA's space science dept participates in GRO


      I just came from a conference room at UNH where all the GRO staff
not down at the cape watched the launch of Atlantis (on time!).    It was really
beautiful to finally see it go up, its been in the works since 78 I think.
The original investigator for UNH, Dr. Jack Lockwood is in semi-retirement,
but was on hand down in Fla.  for the launch.   Data my actually come in soon,
which will make lots of people on the 3rd floor of UNH's Science and Engineering
Research Building here really busy and happy to be so.


                Korac MacArthur (not working for GRO, but doing
                    cosmic ray stuff next door)

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

Date: 5 Apr 91 16:43:13 GMT
From: usc!sdd.hp.com!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Chemical rocket complexities (was Re: "Follies")

In article <[e-mail]> [e-mail] (Glenn A. Serre) writes:
>Rocket development should be made more commercial, as opposed to
>governmental.  Anyone out there disagree?
>Government-sponsored development should concentrate on exotic technologies
>like gas-guns, EML, tethers, etc.  Anyone out there disagree?

Agreed on both.  However, government-sponsored *research*, as opposed to
development, should cover both, in the same way that NASA's aeronautics
research covers both incremental improvements of existing technology and
exploration of new technology.
--
"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: 5 Apr 91 18:08:07 GMT
From: agate!bionet!uwm.edu!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Laser launchers

In article <[e-mail]> Ian Stirling <[e-mail]> writes:
>                                             what is a laser
>launcher? I have heard some references to it,Is it using a ground
>based laser to heat fuel on-board a vehicle so that the fuel boils
>violently,propelling the vehicle.

That's roughly the idea, except one wants to produce high-temperature
gas, not just boil the stuff.  The purest design just attaches a slab
of propellant to the back of the payload, with a small laser pulse
vaporizing a thin layer of the propellant slab and a much larger
pulse superheating the vapor, at a repetition rate of a few hundred Hz.

>Is this a current technology or does
>it still need massive advances in laser technology?

It depends on the size of your payload.  A system to lift manned spacecraft
would require gigawatt lasers, well beyond the current state of the art.
If you're willing to settle for 20kg per shot, the laser is still big but
is the sort of thing that could reasonably be built as a custom job today.
Funding is a much bigger problem than technology.
--
"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

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

ReSent-Message-ID: <[e-mail]>
Resent-Date:  Fri, 05 Apr 91 13:53:33 EST
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Date:         Fri, 5 Apr 91 02:26:00 EST
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #362
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

Re:  Launch Technology:

   From April 4:

>How about those Dinosaurs (oops, I mean Titans)?  Yes, $300+ million in a
>ball of smoke sure looks pretty, if you are into expensive fireworks
>shows, and don't care too much about reliable transporation.  Titan IV
>costs will now rise to Shuttle levels, and we will be lucky if Titan
>IV can catch up to Shuttle's reliability %.  So much for the "expendable
>vs. reusable" debate.  In the long run, they are both losers, and those
>of us who want to get our payloads into orbit are the biggest losers of
>all.

>It's time for USAF to go to smaller, more redundant payloads and launchers,
>and start looking at the alternatives to chem rockets.  These dinosaurs
>are history.

Well, Supposedly, the Shuttle would make Expendables history,  too.
So much for the unproven,cool-sounding-stuff-is-better-than-rockets line.

>Wound casing or metal, they both fail far too frequently for reliable
>transportation.  No, I'm blaming $tens of billions down the tubes for
>chemical rocket research, money that could have been much better spent on
>the basic science behind superconductors, gas guns, lasers, et. al.  Well,
>that's all water under the bridge, but the future lies ahead -- let's
>do it right this time!

1)  The basic science IS being done.  It's the engineering that's not, mainly
    becuase of cost.  Maaybe the science will come through for us.

2)  If we were to put all rocket $$ into new technologies, what would we launch
    with in the interim?

(later comment about the insurance cost for an EM gun being indeterminable):

>Not necessarily.  Insurance costs are based on reliability, which
>in guns is typically 2-3 orders of magnitude greater than for rockets.

HUH?
On what data is this conclusion founded?  I haven't seen or heard of any EM
launches that actually put something into orbit.

 >EML's should be designed, owned and operated privately.  Therefore, we
 >will avoid aerospace/chem rocket world concepts of launch cost and
 >operation.

This argument has been posted countless times with regard to chems, too. ANY
technology will be cheaper if the gov doesn't have a hand in.

>The choice is between large ($4-5 billion) chemical rocket
>projects, which are proven incapable of significantly lowering launch
>costs, or smaller ($100-$500 million) R&D/prototyping projects to
>demonstrate a whole suite of new technologies (gas gun, EML, laser
>launch, etc.).  If EML passes this phase, we would go to a $1 billion
>first-generation system, which would dramatically and quickly lower launch
>costs.  We can introduce a greatly superior technology for less than
>the cost of building yet another chemical rocket.  This is a whole new
>ballgame.

Point:  It has not been *proven* that chems can't lower lauch costs.  For
        example, cost's may fall as more private companies launch, or as
        market demand rises.  Proof requires testing of hypotheses.

Point:  No other system HAS PROVEN capable of the basic goal: Launching a
        payload.  Only chems have even actually put something in orbit.
        ( ESPECIALLY for a lower cost, to boot.)

Point:  There is still the question of whether or not you could actually
        produce the speed necessary  to punch out of the atmosphere with a EM
        gun.  "If we had a globe-encircling  accelerator..." (Which seems the
        most practical right now, from what I've seen)

Point:  R&D IS BEING DONE on this stuff.  You seem to be saying we should scrap
        all chemical based rockets right now.

I can imagine you back in the 1900's  arguing that since cars are so slow and
noisy, pollution-ridden, and unrealiable that we should move on to the
hovecraft or the monorail.  Both of these, BTW, were supposed to transform our
'basic transportation' too.

Please don't mis-interpret me.  There's nothing wrong with exploring options.
But theres miles between that decision and the all-out condemnation of a
systtem based on speculation, or initial ccalculation, of something better.

Final point:  If we want to build that Ifrastructure, the REAL question is not
how much each pound will cost  to launch, but whether we can get back more $$
than we launch.  Chemical rockets could be 10 times worse, and still be a valid
system, based on this criteria.

Tommy Mac
18084tm@msu
Acknowledge-To: <18084TM@MSU>

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

End of SPACE Digest V13 #370
*******************