Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_5/V13_529.TXT

Internet Message Format | 1991-06-28 | 15KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/Ac=BN7C00WBwQ5T05=>;
          Sun, 12 May 91 01:44:40 -0400 (EDT)
Message-ID: <Mc=[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sun, 12 May 91 01:44:34 -0400 (EDT)
Subject: SPACE Digest V13 #529

SPACE Digest                                     Volume 13 : Issue 529

Today's Topics:
             Re: Saturn V vs. ALS
               Re: Saturn V and the ALS
             Re:  Saturn V vs ALS
    Re: Saturn V DDT&E costs (was: SPACE Digest V13 #494)
       Re: Ethics of Terraforming (was Re: Terraforming Venus)
                Re: IT'S OVER
        Re: Hypersonics ... paritcularly Hotol
                Re: IT'S OVER

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 29 Apr 91 20:54:06 GMT
From: unisoft!hoptoad!pacbell!pacbell.com!mips!zaphod.mps.ohio-state.edu!ub!ubvmsb.cc.buffalo.edu![e-mail]  (Craig L Cole)
Subject: Re: Saturn V vs. ALS

In article <[e-mail]>, [e-mail] (Henry Spencer) writes...
>In article <[e-mail]> [e-mail] (Frank Crary) writes:
>>The following small launch vehicles are being designed by US firms, without
>>government support.
>>
>>Industrial Launch Vehicle, by American Rocket Company.
>
>Project dead.  Amroc is now marketing its hybrid-rocket technology to others
>rather than trying to build its own launcher.  It might have been different
>if George Koopman had lived... :-(

Is the ILV the same as the Aquila rocket that I read Amroc was pushing
for Iridium? It seemed Amroc might be making progress. (This was
only about 2 months ago that I read it. I think it was a short blurb
in Ad Astra.)

They DID have really interesting engines -- liquid/solid hybrid, safe
for the environment... I was kinda rooting for them.

Craig Cole
[e-mail]
[e-mail]

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

Date: 7 May 91 23:27:55 GMT
From: wuarchive!sdd.hp.com!caen!news.cs.indiana.edu!noose.ecn.purdue.edu!en.ecn.purdue.edu![e-mail]  (/dev/null)
Subject: Re: Saturn V and the ALS

In article <[e-mail]>, [e-mail] (Allen W. Sherzer) writes:
> In article <[e-mail]> [e-mail] (Paul Blase) writes:
>
> With all due respect I think it is you who are missing the point. Everything
> you say below about the design goals where said about the Shuttle as well.
But may not have accomplished, Allen!  The shuttle not accomplishing its goals
DOES NOT make another attempt doomed.  Please get this notion out of your
head! :)

> Why is it any different this time?
It not the Shuttle.  Why Should it be the same?

>
> >hauler.  The end goal is minimization of launch costs, NOT maximization
> >of performance.  To this end:
>
> Depends on who you ask. Several ALS people do indeed say that one ALS
Try ALS people - they are designing it!  It doesn't matter what
Joe Schmoe Government official *thinks* its going to be, what the
designers make it is what its going to be!

> follow-on which lifts 50K pounds. To NASA it lifts 150K pounds. They
> are so far apart that the Vice President recently put off any decision
> until 93.
>
Good 'ol Dan Quayle - that paragon of decision making competance - :)
And it sounds like

> So was the Shuttle. Why will this be any different?
It is not the Shuttle.  Why should it be the same?

> So was the Shuttle. Why will this be any different?
It is not the Shuttle. Why should it be the same?

> So was the Shuttle. Why will this be any different?
It is not the Shuttle. Why should it be the same?

>
> But this number is interesting. Two contractors have offered to build
> for a fixed price launchers which will launch 100K pound payloads. They
> will do it in half the time and 5% of the cost of ALS. Operational costs

You know, your estimate of costs keep dropping ....
(Last time I tuned in it was 20% of the cost :) )

>
> In this time of high taxes and deficits why do you insist on spending
> dollars on what we could have for pennies?

How do you know (other than hearsay) that we can?

--
+-----------------------------------------------------------------------+
| Society of Philosophers, Luminaries,           | Brent L. Irvine       |
| and Other Professional Thinking People.....   | Only my own ramblings |
+-----------------------------------------------------------------------+

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

Date: 8 May 91 17:11:20 GMT
From: snorkelwacker.mit.edu!think.com!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re:  Saturn V vs ALS

In article <[e-mail]> [e-mail] (Brett Vansteenwyk) writes:
>... what about spending some of this
>development money in a supersonic transport? ...
>The reasoning is thus:  to support a Pegasus type launcher, if not Pegasus
>itself...

It is unlikely to be help much unless you go hypersonic rather than
supersonic.  The major benefit of air launch for Pegasus is the higher
altitude rather than the speed, and Pegasus's launch altitude already
gives you most of the attainable altitude benefit.  The difference
between 250m/s (B-52) and 1000m/s (SR-71) speed at launch is not all that
significant when circa 8000m/s is needed for orbit.

A much simpler and cheaper way to get that extra speed and altitude, given
ample budget and an absence of other constraints, is just to put another
rocket stage under the thing.  It makes little sense to build an aircraft
capable of a wide variety of performances including sustained supersonic
cruise if all you want is one quick push to high speed and altitude.

The approach is potentially interesting *if* you are building a supersonic
transport for other reasons.  Debate is still open on whether that is a
reasonable thing to do, given concerns about economics, sonic boom, and
atmospheric effects (e.g. ozone layer).

>always been curious as to what difference using the XB-70 would have made to
>the X-15 or its successor.

In fact, the loss of the second XB-70 was a significant factor in the death
of the X-15-successor project.  (The first did not have the definitive control
systems and was not considered suitable as a carrier aircraft.)
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: 9 May 91 01:24:37 GMT
From: stanford.edu!agate!headcrash.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Saturn V DDT&E costs (was: SPACE Digest V13 #494)

In article <[e-mail]> [e-mail] (Mary Shafer) writes:
>Actually, being an engineer and being accustomed to _one_ answer, plus
>and minus some delta, I find the determination of costs to be irrational
>at best and downright silly at worse.  I suspect that the real cost is
>quite different from the apparent cost, by the time you add in the tax
>break for IR&D, the interest the gov't makes by paying late, the cost
>of money, etc.

"Costing is a BLACK ART" - Robert Zubrin, May 1990.

In fact, for his manned mars archetechure, Mars Direct, he got the costs
by showing his concept to groups of NASA engineers, saying "how much
could this possibly cost," and taking the highest answer as an upper
bound.

                  Frank Crary
                  UC Berkeley

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

Date: 9 May 91 02:29:58 GMT
From: snorkelwacker.mit.edu!think.com!zaphod.mps.ohio-state.edu!rpi![e-mail]  (Jim Kasprzak)
Subject: Re: Ethics of Terraforming (was Re: Terraforming Venus)

In article <[e-mail]> [e-mail] (Frank Crary) writes:
>In article <[e-mail]> [e-mail] (Lon Stowell) writes:
>>  Has anyone considered making a "planetary park" out of Mars to
>>  preserve Mt. Olympus and some of the other formations?  Just
>>  cause it is lifeless doesn't mean it is without beauty...and
>>  worth preserving.
>>
>>  Go terraform an ugly planet.
>
>Could you identify a "ugly planet" for me. I find parts of ALL the planets
>we have photographed quite wonderful. But it is not reasonable to say that
>terraforming Mars would destroy Mons Olympus. Even with running water,
>errosion would take longer than human history to remove Olympus. Also,
>while Olympus is beautiful, might it not be even more wonderful with trees
>growing on it?

 Even with an Earthlike atmosphere on Mars, most of Olympus would be
high above most of the sources of erosion. Remember it's, what, twice
the height of Everest? (Can't remember exact numbers, but anyhow) You
won't find trees anywhere near the summit, nor running water or winds
that would amount to much. A glacier might form, but I'd think that
would only add to the beauty of an already awe-inspiring mountain.
------------------------------------------------------------------
     __  Live from Capitaland, heart of the Empire State...
 ___/  | Jim Kasprzak, computer operator @ RPI, Troy, NY, USA
/____ *| Disclaimer: RPI pays me to work, not to think.
     \_| "A spirit with a vision is a dream with a mission" -Rush
      ====  e-mail: [e-mail] or [e-mail]

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

Date: 8 May 91 12:16:00 GMT
From: dev8a.mdcbbs.com![e-mail]
Subject: Re: IT'S OVER

In article <[e-mail]>, [e-mail] (John A. Weeks III) writes:
>
> Now what does any of this have to do with sci.space.  Will humans ever
> develop warp drive?  Are there any holes in the quantum theory and
> relativity that might allow warp drive?
>

Well now, I'll toss one out. If you caught the last installment of
"The Astronomers", you will know that there is a lot of interest in
studying gravitational waves, and an experiment is underway in
several countries called LIGO (Laser Interferometry Gravity Observatory)
to try and detect these waves.

During the making of the show, I got into a long discussion with one of
the consultants regarding the ins and outs of inescapable gravity
fields, gravity propagation possibly exceeding the speed of light, etc. I
wound up making a rather large cash bet that, once we are able to detect
gravity waves, we would discover that they make a far less cluttered
means of interplanatary communications ( and that we are more likely to
detect another civilization using gravity wave communications than radio).

Comments? Ideas? Speculations?

The chair hereby throws the floor open to inuendo and rumor!

Michael

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

Date: 10 May 91 04:43:50 GMT
From: stanford.edu!agate!lightning.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Hypersonics ... paritcularly Hotol

Last I heard, HOTOL was dead in the water, for political reasons:
British Aerospace has, as I understand it, exclusive rights to the
engine design, (called I think "sparrow"), so long as they pay to
develop it. They have no interest, costomers, or budget to develop
a real spaceplane, but they do not want to loose rights to the engine.
As a result, they budget a trivial amount to the HOTOL program, so that
they can claim to be "developing" the design.

                      Frank Crary
                      UC Berkeley

PS: This is a rumor... If there are any angry BA people out there,
correct me, try to sue me, or go away.

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

Date: 9 May 91 05:29:10 GMT
From: dog.ee.lbl.gov!hellgate.utah.edu!caen!zaphod.mps.ohio-state.edu!rpi!usc!jarthur!nntp-server.caltech.edu![e-mail]  (Steinn Sigurdsson)
Subject: Re: IT'S OVER

In article <[e-mail]>, ccoprmd@prism (Matthew DeLuca) writes:
>In article <[e-mail]> [e-mail] writes:
>
>>During the making of the show, I got into a long discussion with one of
>>the consultants regarding the ins and outs of inescapable gravity
>>fields, gravity propagation possibly exceeding the speed of light, etc. I
>>wound up making a rather large cash bet that, once we are able to detect
>>gravity waves, we would discover that they make a far less cluttered
>>means of interplanatary communications ( and that we are more likely to
>>detect another civilization using gravity wave communications than radio).
>
>One question...does the ability to *detect* gravity waves imply the ability
>to *generate* gravity waves?  From what little I know of the field, gravity

That depends, here at Caltech, in the room next door is a portable
gravitational wave (gravity waves conventionally refer to surface
waves in fluids) generator!!! It is a standard exercise for the GR
courses here to calculate the flux ;-) It is rather small.
(Hint, I feel in imminent danger of being shredded by the tidal
forces so generated)

>waves are thought to be generated primarily by supernovas...am I correct

The favoured sources at the moment are hard binaries spiralling in,
generating "chirps" of gravitational waves, estimates of detectable
signals are from one per year to one per day, depending some
assumptions made. The supernovae rate is more like 1 per 10 years
or maybe a bit better. See Thorne in "300 years of Gravitation"
for details.

>in this assumtion?  I'm not sure I see how we are going to generate something
>like that here on earth; if we have the ability to modulate gravity (which
>I assume we would have to do to make use of it as a communications medium,
>other than a Morse-like code) we're going to be able to do a heck of a lot
>more with it than communicate...
>

In principle there is no reason why detectable gravitational waves
cannot be modulated, although I think you'll find the bandwidth
reasonably available is less then wonderful. However, this would
require several orders of magnitude improvment in the technology of
generation and (to a lesser extent) detection. Or a _major_ scientific
breakthrough.

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

End of SPACE Digest V13 #529
*******************