Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_4/V15NO441.TXT

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Date: Fri, 20 Nov 92 05:04:12
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #441
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri, 20 Nov 92       Volume 15 : Issue 441

Today's Topics:
                FREE-ENERGY TECHNOLOGY For Spacecraft
                   Galileo HGA: Hypothesis (4 msgs)
                     Lunar "colony" reality check
                 Lunar "colony" reality check, part 2
   opening of the first self-sufficient solar house, Press Release
                    ROTATION OF THE MOON (2 msgs)
                          Scientific method
                     Scientific method (followup)
                     Shuttle replacement (4 msgs)
                         Space suit research?
              SSTO Viability (was: Shuttle replacement)

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

Date: Thu, 19 Nov 1992 16:20:18 GMT
From: George Noyes <[e-mail]>
Subject: FREE-ENERGY TECHNOLOGY For Spacecraft
Newsgroups: sci.space

>In article <[e-mail]> [e-mail] writes:
Note: the following comments plagerized......
>        [vague generalities removed]
>        [folklore removed]
>        [political dogma removed]
>>                                   Robert E. McElwaine
>>                                   B.S., Physics, UW-EC
>

        What has this McElwaine been smoking?  It must be pretty good!

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

Date: Thu, 19 Nov 1992 23:29:23 GMT
From: Henry Spencer <[e-mail]>
Subject: Galileo HGA: Hypothesis
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>        Another naive query about Galileo's HGA problem.
>        Can it send data at a high rate but with little power?

The HGA is useless in its current state.  The low-gain antennas can send
high-rate data, if a receiver is relatively close.

>        If so, what if a relay craft were sent after it to gather and
>        send information back at the intended rate?

This was the most technically-feasible way to salvage the complete mission.
Put the relay craft in high orbit around Jupiter, and the Galileo LGAs
can get the high data rate that far.  A light relay craft could be
launched on a more direct trajectory to reach Jupiter in time.  It hasn't
been done, basically because it required commitment to a modest but
substantial expenditure very quickly, and NASA can't *do* that nowadays.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Fri, 20 Nov 1992 00:09:16 GMT
From: Leigh Palmer <[e-mail]>
Subject: Galileo HGA: Hypothesis
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>
>
>
>        Another naive query about Galileo's HGA problem.
>
>        Can it send data at a high rate but with little power?
>
>        If so, what if a relay craft were sent after it to gather and
>        send information back at the intended rate?
>
>        Would this work?
>
>
>      o < < < < < < < < < < < <  )-x  . . . . )-G
>
>      earth                     relay       Galileo
>

Sure, but how are you going to *keep* the relay at that point between Earth and
Galileo? You'd pretty much have to put it in orbit around Jupiter or place it
in the inner Lagrangian point. In any smaller orbit it'd orbit faster than
Jupiter, and thus spend most of its time at least as far from Galileo as Earth
is now.

Another idea: Put a really large radiotelescope in Earth orbit and hook it to
the Deep Space Network. I saw a marvelous scheme for doing this once in a story
about nitinol, the memory alloy. One makes a flimsy lacework paraboloidal
antenna which has a conductive path arranged such that applied current flows
through all the nitinol wires in the structure. It is fabricated at high
temperature and then cooled off, wadded into a much smaller package, and
shipped to orbit. Once there a large current throgh the wires restores the
paraboloid to its original shape!

Oh well, so much for the science fiction writing today. I'll go finish marking
exams.

Leigh

Leigh

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

Date: Thu, 19 Nov 1992 23:22:55 GMT
From: David Knapp <[e-mail]>
Subject: Galileo HGA: Hypothesis
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>
>
>
>        Another naive query about Galileo's HGA problem.
>
>        Can it send data at a high rate but with little power?
>
>        If so, what if a relay craft were sent after it to gather and
>        send information back at the intended rate?
>
>        Would this work?
>
>
>      o < < < < < < < < < < < <  )-x  . . . . )-G
>
>      earth                     relay       Galileo
>
>

It's not a naive query at all since it was already considered by NASA.
The problem is getting the major funding this would require, and
getting things designed, built and launched in time.  There might
Not even be a window left for a rendezvous.
--
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   [e-mail]

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

Date: Fri, 20 Nov 1992 00:54:26 GMT
From: Henry Spencer <[e-mail]>
Subject: Galileo HGA: Hypothesis
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Leigh Palmer) writes:
>... how are you going to *keep* the relay at that point between Earth and
>Galileo? You'd pretty much have to put it in orbit around Jupiter...

You *have* to put it in orbit around Jupiter.  Putting a relay halfway
between Earth and Jupiter is utterly useless; it has to be practically
in Galileo's back pocket for it to receive high-rate transmissions from
the low-gain antennas.

>Another idea: Put a really large radiotelescope in Earth orbit and hook it to
>the Deep Space Network...

There really is very little advantage to doing this in orbit.  Lighter
construction, yes, but much higher costs and no maintenance access.
With the current state of space transportation, you're better off building
it on Earth.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 22:31:16 GMT
From: Henry Spencer <[e-mail]>
Subject: Lunar "colony" reality check
Newsgroups: sci.space,alt.sci.planetary

In article <[e-mail]> [e-mail] (Wayne Harvey) writes:
>I seem to remember some theory a while back that the moon was actually
>*captured* by Earth at some stage (I think it was about 800 million
>years ago)...

The three classical theories of lunar formation -- fission from Earth,
formation in orbit around Earth, and capture -- were all pretty much
destroyed by analysis of the Apollo samples.  Earth and Moon are too
similar to have formed far apart, and too different to have formed
together unless you add some extra factor to give them very different
histories.  The giant-impact theory fits the bill, and the facts.

>... when you assume that the only mineral explorations done on
>the lunar surface were conducted in the equivalent of the Sahara.

Not a very tenable assumption.  For one thing, those explorations got
samples from a much wider range of locations, courtesy of splashes
from meteorite impacts.  For another, even the "local" rocks differed
a great deal between sites.  (The lunar scientists were against landing
Apollo 12 at a site that looked so similar to the Apollo 11 site, but
they shut up when they saw the preliminary results from the Apollo 12
samples.)  There's no doubt that we've sampled only a little of the Moon's
geological diversity -- and useful ore bodies are often very localized
things, the results of extreme conditions -- but we do have enough data
to be fairly confident of the average composition.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 21:58:50 GMT
From: Edmund Hack <arabia!hack>
Subject: Lunar "colony" reality check, part 2
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
> [regarding the need for spares for a lunar base]
>What can be done to help
>alleviate the problem? Breaking designs up into smaller modules, and having
>as many identical modules as possible might help. Using initially identical
>but reconfigurable modules could also be useful. (Earthbound example: I just
>finished a circuit design in which a high percentage of the logic is in
>identical reprogrammable logic devices, each one programmed differently.
>By keeping a relatively small number of spares on hand, I could replace
>any of these devices that might fail. If for some reason I had no spares
>and really needed to use the circuit, I could cannibalize a component from
>a less-critical area, and use it to replace a failed device in a more-critical
>area.)

This is one idea that the NASA First Lunar Outpost has proposed. Even
Freedom has (partly) endorsed this, with only a few types of circuit
boards for the onboard computers. Having the ability to do sub-board
level repairs could greatly improve availability of the systems and
reduce the logistics burden, IMHO.  We are attempting to quantify this
in the future.
>
>As I posted long ago, I suspect a first mission would be likely to choose to
>start with a minimal set of spares, and hope to later build up a stock by
>periodic resupply. (Or they might send supplies ahead of them, by unmanned
>vehicle.)

Both are being looked at.  Also, most scenarios have the base landing
and auto-deploying a few months before the crew so that a couple of
night/day sequences happen, shaking early failures out.  Massis
allocated in the crew lander for last-minute spares to be included.


--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

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

Date: Thu, 19 Nov 1992 23:01:24 GMT
From: Henry Spencer <[e-mail]>
Subject: opening of the first self-sufficient solar house, Press Release
Newsgroups: sci.energy,sci.space

In article <[e-mail]> [e-mail] (Jonathan Bayer) writes:
>The Appollo 13 failure was due to an oxygen tank being dropped during
>assembly into the service module.  The drop was about three inches, and
>the tank was throughly test after it was dropped.  However, a small tube
>apparently had been dislodged, and it wasn't detected during the
>testing.  It was only functional in weightlessness.  The tube was some
>sort of relief tube.  When they turned on the internal mixers in flight
>(the mixers kept the O2 from clumping in one area) there was an
>explosion...

This actually leaves out an important intermediate step.  The (probable)
drop damage to the tank wasn't directly responsible for the accident.
Its main effect was to make it difficult to empty the tank after ground
tests.  And that is where the real problem crept in.  When the tank
wouldn't empty after a test, the tank's heaters were used to boil it
dry... and thanks to another error or two along the way, the tank was
drastically overheated and nobody realized it.  This roasted the Teflon
insulation on the in-tank wiring.  In flight, when the tank stirrer
was turned on, shorts through the ruined insulation produced sparks,
the insulation ignited, and things went downhill quickly from there.

References:

Cooper, "Thirteen:  The Flight That Failed".
Murray&Cox, "Apollo:  The Race To The Moon".
NASA SP-350, "Apollo Expeditions To The Moon".
NASA SP-4204, "Moonport".
NASA SP-4214, "Where No Man Has Gone Before".

>... When they released the
>service module they were able to see where the explosion had occurred.

Actually, not true except in a very general sense.  They didn't have a
very good view and that bay of the Service Module was quite a mess.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 22:02:46 GMT
From: Michael Andersson <[e-mail]>
Subject: ROTATION OF THE MOON
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (David Geiser) writes:
>> The same thing is happening, much more slowly, to the earth --
>> friction with the tides and within the "solid" earth is slowing the
>> rotation rate by something on the order of 1 sec every century. We can
>> actually measure it (the slowdown) nowadays. Love those atomic clocks!
>
>Do you know if that rate is constant?  Say around 63M years ago,
>around the time of the end of the dinosaurs, the day would have
>been 175 hrs longer!


No.  If the rotation is slowing, then days used to be shorter.

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

Date: Thu, 19 Nov 1992 23:16:13 GMT
From: David Knapp <[e-mail]>
Subject: ROTATION OF THE MOON
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Matthew Sheppard) writes:
>
>Question:
>    Why is the moon orbiting the earth at the same rate it rotates?  It
>can't be pure luck that the same side of the moon is always facing us.

It's not pure luck. In fact, this phenomenon, called 'tidal locking' is
almost the rule in the solar system.

Tidal forces from the Earth and Sun cause a 'bulge' in the moon. On earth,
you can literally see the bulge effect in the tides. On the moon (and
on the earth too, actaually) the body *itself* is bulged out. As the
moon rotates through this bulge, the flexing causes the moon to warm up
and dissipate the rotational energy.  After a while, the moon has
'despun' and no longer rotates through the bulge. That's how it is now.


>Perhaps someone already tried to send us a message and we just haven't
>read it yet.


I won't touch that one.
--
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   [e-mail]

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

Date: Fri, 20 Nov 92 01:29:11 EST
From: John Roberts <[e-mail]>
Subject: Scientific method

-From: [e-mail] (fred j mccall 575-3539)
-Subject: Re: NASA Coverup
-Date: 18 Nov 92 21:38:47 GMT
-Organization: Texas Instruments Inc

->]No, what you have is necessary, but not sufficient.  It must also be
->]testable and make some predictions about the universe to be as viable as
->]relativity (General or Special). (This is true to first order.  I am
->]aware that there is some discussion in philosophy of science about
->]falsifiability, as well as other nits.)

-This is pretty much REQUIRED for a scientific 'theory' -- it must
-exhibit sufficient predictive power to be falsifiable.  In other
-words, it must predict things that we can go look at that we don't
-know the answers to yet, so that we can then go and see if the things
-that it predicts are true.

[e-mail] - I don't speak for others and they don't speak for me.

For better or worse, that's what the "scientific method" is today, but it
was not always thus. Gregor Mendel, pioneer geneticist, used a somewhat
different method. I'm not sure exactly what he did, but I believe that in
essence, he developed his theory and ran his experiments more as "parallel
processes" than what would be considered acceptable today.

I've sometimes wondered whether there's a lesson to be learned in the
alternative techniques used in the past. Others may be thinking along similar
lines - for instance, for instance, the Earth-impact model of the formation
of the moon has risen from obscurity to the "most favored model", with
(as far as I know) little or no new input of information - it's based on
mathematical models and old Apollo and Voyager data. (Eventually, of course,
somebody will try to come up with new experiments to "test" the model, but I
consider the fact that it seems to have effectively achieved the status of
"theory" without the traditional requirement of further testing to be
significant.)

Does anybody recall the details of the technique Mendel used?

John Roberts
[e-mail]

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

Date: Fri, 20 Nov 92 01:44:43 EST
From: John Roberts <[e-mail]>
Subject: Scientific method (followup)

For those who *insist* on the classical method of development of theory
followed by testing for previously unobserved supporting phenomena, the
current condition of HST offers a priceless opportunity. They can develop
their hypotheses now, then after the installation of WF/PC II and COSTAR,
they can look again in more detail. (This was discussed on Thursday with
respect to the discovery of the accretion disk.)

John Roberts
[e-mail]

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

Date: Thu, 19 Nov 1992 23:09:04 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Hugh Emberson) writes:
>Henry> Gary Hudson claims that you could put six SSMEs on a shuttle external
>Henry> tank, without SRBs, and get it into orbit carrying a payload about 50%
>Henry> greater than the shuttle's...
>
>This sounds a lot like Shuttle-C...

Not very closely related, actually, since Hudson's design deletes the SRBs
and doesn't put engines+payload in a mock-orbiter.

>...whatever happened to that idea?

Too little demand and too much politics.  It quietly died.

>...idea was to take a normal stack (an ET and 2 SRBs) and bolt on a
>fairing containing the payload and some SSMEs in place of the shuttle.

That's right.  The fairing started out to be a stripped-down orbiter,
but it didn't take long to figure out that if you're throwing it away,
there are cheaper ways to build it.

>... Some of the pictures I saw had 4 SRBs.

There have been a wide variety of shuttle-derived heavylift-booster
designs over the years.  It looks like a sensible thing to do if you've
got a few heavy payloads to lift and don't want to invest in developing
a whole new launch system (including new pads etc.) just for them.  The
idea has been revived once again by Griffin's how-to-launch-the-space-
station "red team".
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 23:23:00 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Carl Hage) writes:
>: This BTW is a source of trouble for SSTO.
>
>A source of trouble? HL20 won't win any arguments claiming to be better
>because it's more expensive...

Remember that money = jobs; being a lot cheaper is *not* an unmixed political
blessing.

The big problem HL20 presents for SSTO is that a lot of NASA people see
HL20 as work for them and SSTO as work for somebody else... and NASA is
the established source of expertise on spaceflight, so any space project
that NASA dislikes has an uphill battle ahead of it.  (This isn't a new
problem, by the way.)  All the more so because SSTO challenges NASA's
credibility, not just its turf, by being (if it works) a vastly-superior
system built at low cost with off-the-shelf technology.  This is bad news
if you've spent your career defending very expensive projects as "the only
way it can be done".

>Claims of $1M or even $10M launch costs seem too low to be believable.
>... Does your info kit offer clear and complete
>information that will convince a skeptic?

Nothing short of a flight demonstration will convince really skeptical
observers.  A successful on-budget DC-X, especially with a demonstration
of rapid reflight with minimal refurbishing, will help a lot.

>It seems like it is a matter of a few simple calculations to show that
>it is theoretically possible/impossible given some basic assumptions
>about current rocket technology like, weight, engine efficiency, fuel
>weight, etc. Presumably you have shown that it is possible.

It's been (theoretically) possible at least since the 60s, perhaps earlier.
(Ed Heinemann, Douglas's military-aircraft miracle-worker, sketched an
expendable SSTO launcher in the late 40s...  Pity he never got the chance
to build it.)
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 23:37:24 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
>... the operation costs do seem quite optimistic, in
>particular I'd have thought the early years operation would be higher
>while ground support learned some maintenance procedures and
>operational experience was developed on what needs inspection and
>refurbishing between flights? I just don't see any way around that,
>are the DCs really that much simpler?

Wrong question.  There are two ways to go about this.  One is to assume
that between-flights turnaround will be very complex, but it will get
better if we look for ways to improve it.  The other is to assume that
it will be simple, although a few complications may be found.  Oddly
enough, only the second approach ever results in something simple and
cheap.  You can always come up with reasons why complexity is needed,
especially after you've already written the manuals and hired the staff.
Simple systems do not evolve from complex ones.

The right question is:  why should the DCs be much more complex than
high-performance aircraft?
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: 20 Nov 92 01:44:36 GMT
From: Steinn Sigurdsson <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

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


   In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
   >... the operation costs do seem quite optimistic, in
   >particular I'd have thought the early years operation would be higher
   >while ground support learned some maintenance procedures and
   >operational experience was developed on what needs inspection and
   >refurbishing between flights? I just don't see any way around that,
   >are the DCs really that much simpler?

   Wrong question.  There are two ways to go about this.  One is to assume
   that between-flights turnaround will be very complex, but it will get
   better if we look for ways to improve it.  The other is to assume that
   it will be simple, although a few complications may be found.  Oddly
   enough, only the second approach ever results in something simple and
   cheap.  You can always come up with reasons why complexity is needed,
   especially after you've already written the manuals and hired the staff.
   Simple systems do not evolve from complex ones.

   The right question is:  why should the DCs be much more complex than
   high-performance aircraft?

Intrinsically I see no reason why an orbital launcher should be
more complex than that - as a matter of practicality though there is the
fact that you have a lot of energy to be controlled in a very short
time - the SSME's power rating is a respectible fraction of US
capacity! Now, the DCs are not being designed on the margin,
they have to be robust if they are not to be stripped down and
inspected every time. I guess my question really is whether they've
succeeded in reducing the number of parts _and_ gotten the reliability
of each part to the point where maintenance will be as low as claimed.
There is no intrinsic reason why it can't be done, but it is not clear
that the knowledge base to decide what is necessary refurbishment and
what is waste is there yet. Of course the only way to find out
is to fly the thing :-)

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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

Date: Thu, 19 Nov 1992 22:40:31 GMT
From: Henry Spencer <[e-mail]>
Subject: Space suit research?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>Okay.  I know commercial jets routinely push 40,000 ft, maybe a bit more.
>the cabins are usually only pressurised to 10 PSI. and they use air cooling
>on lots of stuff.  they also have gear in unpressurised bays that seem
>to cope...

I don't know for sure, but I believe almost all of their avionics are in
pressurized bays.  There isn't much unpressurized space in a pressurized
airliner, except at the extreme nose and tail.

>Military jets run up to 70,000 ft and over 100,000 on special
>trajectories, but if they dont use air cooling then that would explain it.

Very few military jets ever get up to 70,000ft.  50,000 is a more typical
ceiling for reasonable configurations.  Only the specialized ones can even
reach 70,000 except in a ballistic trajectory.

>I think the blackbirds cruise at 100,000 ...

This is popular mythology, but so far as I know it has never been confirmed.
The openly-admitted Blackbird altitude records are in the 70-80 range.

>Actually could a blackbird pilot get astronauts wings?  on some sort of ballistic shot????

It's most unlikely.  All of the altitudes we're talking about are *way*
below "astronaut wings" altitude.  And the Blackbird is not particularly
well-suited to ballistic trajectories; the ballistic-trajectory altitude
record is held by the F-15, not the Blackbird, and it's only about
100,000ft.

>>>ALSO in apollo were EVA's part of the planned mission?
>>Yes, both on early flights for testing, and on the later lunar missions
>>for recovery of film canisters from the SM survey-equipment bay...
>
>i thought they needed to get something out of the SM on the trip home.

Please read what I wrote, Pat!  On the later lunar missions the SM had one
bay full of remote-sensing equipment, and they needed to recover film from
it.  There were no such EVAs on the earlier lunar missions.
--
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  [e-mail]  utzoo!henry

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

Date: Thu, 19 Nov 1992 22:52:13 GMT
From: Bill Goffe <[e-mail]>
Subject: SSTO Viability (was: Shuttle replacement)
Newsgroups: sci.space.shuttle,sci.space

[e-mail] (Allen W. Sherzer) writes:

[material deleted]

>>When a project goes from zero visibility to the network news, it makes
>>all the difference in the world because most politicians (and most
>>Americans) don't care about anything that doesn't make the network
>>news.  (Let's just hope the launch happens on a slow news day.)

>We need to do other things as well. There was an article on this in
>a recent issue of Design News and the British newspaper The Guardian
>is also working on an article.

I understand that there will be an article in the British newspaper
The Daily Telegraph on Nov. 20.

Bill Goffe
[e-mail]

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

From: Steinn Sigurdsson <[e-mail]>

Newsgroups: sci.space.shuttle,sci.space
Subject: Re: Shuttle replacement
Message-Id: <[e-mail]>
Date: 19 Nov 92 21:50:44 GMT
References: <[e-mail]> <[e-mail]>
    <[e-mail]>
Organization: Lick Observatory/UCO
Lines: 60
Nntp-Posting-Host: topaz.ucsc.edu
In-Reply-To: [e-mail]'s message of 19 Nov 92 20:23:02 GMT
Sender: [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:


   In article <[e-mail]> [e-mail] (Carl Hage) writes:

   >Although Gore was flamed here for this speech, it would seem to me that he
   >could be a very strong supporter of SSTO.

   Let's hope so.

   >Development of DC-X has been relatively low cost, but can you convince
   >everyone that DC-1 will be cheap? Are the cost predictions realistic?

   No, you can never convince everybody. However, the cost predictions are
   the best available. If nothing else the fact that the design and construction
   of DC-X is on time and on budget gives a good indication that their cost
   estimators know what they are talking about.

 ...

   >Claims of $1M or even $10M launch costs seem too low to be believable.

   Only circumstantial. If the models are correct than DC will fly for
   $1 to $10M per flight. However we need DC-X to verify the models.

   However the circumstantial evidence supports it. After all, the cost and
   part count of a launcher is about the same as a commercial airliner. The
   rest is up to the technology and to date nobody questions that it can
   be done as far as the technology is concerned.

While I'm strongly in favour of the DC-X/Y/1(-2-3!) this causes me
a little concern. I'm willing to believe that the DCs can be developed
and constructed on budget as long as they can avoid some appropriations
nightmare, but the operation costs do seem quite optimistic, in
particular I'd have thought the early years operation would be higher
while ground support learned some maintenance procedures and
operational experience was developed on what needs inspection and
refurbishing between flights? I just don't see any way around that,
are the DCs really that much simpler?

   >For point 3, there seems to be a particular timetable in mind for
   >producing DC-X/Y/1. How does that timetable compare with the alternatives?

   An operational DC-1 should be flying in 97 IF (this is a big if) we can
   get Congress to fund it properly. BTW, since we are only looking at $1B
   per year over about four years this is an achieveable goal provided
   supporters put and keep pressure on Congress.

Hmm, didn't you just say that Congress should just fund the DC-X,Y?
I thought after prototyping McD would pay for construction of the
production models! ;-)

   +---------------------------------------------------------------------------+
   |  [e-mail]     |  nothing undone"                                       |
   +----------------------156 DAYS TO FIRST FLIGHT OF DCX----------------------+

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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End of Space Digest Volume 15 : Issue 441
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