Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V15_6/V15NO633.ZIP/V15NO633

Internet Message Format | 1993-07-13 | 33KB

Date: Tue,  5 Jan 93 05:14:40
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #633
To: Space Digest Readers
Precedence: bulk


Space Digest                Tue,  5 Jan 93       Volume 15 : Issue 633

Today's Topics:
                  *** BUSSARD RAMSCOOP *** (2 msgs)
                           Bussard ramscoop
                          Dante Advisory #5
                      Energy production on Earth
                Fabrication (was fast track failures)
                        Fiber optic umbilical
                         Latest Pegasus news?
       Let's be more specific (was: Stupid Shut Cost arguement
      Let's be more specific (was: Stupid Shut Cost arguements)
                          Moon Dust For Sale
           Overly "success" oriented program causes failure
                        Space List Flame Wars
                           SSTO vs 2 stage
        Stupid Shut Cost arguements (was Re: Terminal Velocity
         Who can launch antisats? (was Re: DoD launcher use)

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

Date: 4 Jan 93 20:59:16 GMT
From: Henry Spencer <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Jason Cooper) writes:
>> Building the ramscoop itself is the easy part (difficult though it is).
>> Getting the hydrogen to *do* something useful, once collected, is hard.
>> Using it as reaction mass for an antimatter-powered jet engine is going
>> to be much easier than trying to burn it raw.
>
>Ah, but that would defeat the entire purpose of the ramjet itself!

No, not really.  Getting reaction mass from the interstellar medium is
still a *lot* better than having to carry it yourself.  This is, after
all, how existing jet engines work.  It's not as good as the ideal of
cruising forever without a fuel tank, but it still could be very useful,
and it's much more practical.

>...carrying around a mass of fuel equal to what you are going to tak
>in in the scoop...

Nope, note that I said "reaction mass".  Until you start getting up to
relativistic speeds, much the most efficient way to use antimatter is
to heat a large quantity of reaction mass with a small quantity of
antimatter.

>... How's a carbon-catalyzed
>reaction sound for getting there (except at the lower end, where we'll
>have to use some conventional engine to attain a speed at which THAT
>reaction is possible)?

The problem with sneaky reactions to get around the glacially slow
fusion rate of ordinary hydrogen is "why doesn't that happen in stars?".
The mere fact that stars (which do contain carbon) are billions of years
old indicates that carbon alone is not going to solve your problems.  To
get a reaction many orders of magnitude faster than the natural ones,
you must use conditions or catalysts which do *not* occur in nature.

Incidentally, to avoid running into the fabled ramscoop speed limit,
you must *not* use an engine design that converts all the kinetic energy
of the incoming gas into heat.  Otherwise your thrust will drop to zero
when the incoming gas temperature reaches the exhaust temperature of
your fusion reaction.  As with chemical jet engines, kinetic heating
of the gas stream is your *enemy*, not your friend, because the reaction
you're using for power produces a fixed final temperature, not a fixed
temperature rise.  The simplest way around this is the Bussard equivalent
of the scramjet:  don't slow the gas down much, just heat it as it goes
past.  Alas, this has the same sort of problem that scramjets do:  to
make a relativistic-combustion ramjet work, whatever heating reaction you
use must be fast FAST *FAST*, because it must happen within microseconds
at the very most.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Mon, 4 Jan 1993 21:22:41 GMT
From: Dave Michelson <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Jason Cooper) writes:
>> Not good enough, alas.  The pressure at the *center of the Sun* produces
>> only the most sluggish hydrogen reaction -- one that will take billions
>> of years to consume the Sun's hydrogen supply.
>>
>> Ordinary hydrogen burns quickly in thermonuclear reactions only under
>> near-supernova conditions.  The heavier isotopes used in fusion bombs
>> burn like gasoline by comparison, to the point where they are distinctly
>> rare in the universe -- even the small supply existing on Earth requires
>> significant effort to explain.
>>
>> Building the ramscoop itself is the easy part (difficult though it is).
>> Getting the hydrogen to *do* something useful, once collected, is hard.
>> Using it as reaction mass for an antimatter-powered jet engine is going
>> to be much easier than trying to burn it raw.
>> --
>> "God willing... we shall return."       | Henry Spencer @ U of Toronto Zoolog
>>        -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry
>
>Ah, but that would defeat the entire purpose of the ramjet itself!  You
>are now carrying around a mass of fuel equal to what you are going to tak
>in in the scoop.  Now we get into all of the standard limitations, as the
>faster you want to go, the heavier the ship's going to get, the more fuel
>you'll have to carry, the heavier the ship's going to get, etc. ad
>infinitum.  The *REAL* advantage of the ramjet is that this is not
>happening.  The fuel is just waiting out there, and it just so happens
>that the faster you go, the more you're going to collect.
>
>Of course, I'm not using the p-p fusion until I'm into the speeds where
>the beta- decomposition involved is not a problem probability-wise, due
>to the large number of chances it will have.  How's a carbon-catalyzed
>reaction sound for getting there (except at the lower end, where we'll
>have to use some conventional engine to attain a speed at which THAT
>reaction is possible)?
>
>                                                Jason Cooper


Good grief, guys.  Since we're speculating all over the place here about
science-yet-to-come, why not build a quark-catalyzed ramscoop.  All the
advantages of muon-catalyzed fusion except that the Quark doesn't decay.
All you have to do is crack open a hadron!  If you want more details,
please let me know and I'll post them.  (I'm only half joking, by the way.
Quark-catalyzed fusion is a "serious" possibility if quarks can be unbound.
Emphasis on the if.)

--
Dave Michelson
[e-mail]

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

Date: Mon, 4 Jan 93 19:28:42 EST
From: John Roberts <[e-mail]>
Subject: Bussard ramscoop

-From: [e-mail] (Jason Cooper)
-Subject: Re: *** BUSSARD RAMSCOOP ***
-Date: 3 Jan 93 15:36:30 GMT
-Organization: TradeNET International Trade Corp.

-> Not good enough, alas.  The pressure at the *center of the Sun* produces
-> only the most sluggish hydrogen reaction -- one that will take billions
-> of years to consume the Sun's hydrogen supply.
->
-> Building the ramscoop itself is the easy part (difficult though it is).
-> Getting the hydrogen to *do* something useful, once collected, is hard.
-> Using it as reaction mass for an antimatter-powered jet engine is going
-> to be much easier than trying to burn it raw.
-> --
-> "God willing... we shall return."       | Henry Spencer @ U of Toronto Zoolog
->        -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

-Ah, but that would defeat the entire purpose of the ramjet itself!  You
-are now carrying around a mass of fuel equal to what you are going to tak
-in in the scoop.  Now we get into all of the standard limitations, as the
-faster you want to go, the heavier the ship's going to get, the more fuel
-you'll have to carry, the heavier the ship's going to get, etc. ad
-infinitum.  The *REAL* advantage of the ramjet is that this is not
-happening.  The fuel is just waiting out there, and it just so happens
-that the faster you go, the more you're going to collect.

A "conventional" antimatter drive uses millions of parts of ordinary matter
for each part of antimatter. Thus if the main thing you carry along is
the antimatter, you can still potentially benefit from gathering your
reaction mass as you go.

John Roberts
[e-mail]

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

Date: 4 Jan 93 20:21:04 GMT
From: Gil Nardo <wet!mcs>
Subject: Dante Advisory #5
Newsgroups: sci.space,comp.robotics

Looks like exploratory robots ought to travel at least in
groups of two.  One specialized for experiments, the other
for critical supplies and repair (the Maytag repair robot?).
--
Gil Nardo                  | [e-mail]
Migrant Computing Services | [phone]
1032 Irving Street, #435   |-----------------
San Francisco, 94122       | Supernova = *!

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

Date: Mon, 4 Jan 93 19:17:40 EST
From: John Roberts <[e-mail]>
Subject: Energy production on Earth

-From: [e-mail] (Woody Ligon)
-Subject: Re: Energy production on Earth
-Date: 4 Jan 93 19:30:26 GMT
-Organization: GE-CRD

-In article <[e-mail]>, [e-mail] (John
-Roberts) wrote:
-> A report on the radio this morning described a genetically engineered
-> bacterium, in which two genes were spliced in to allow it to do a very
-> good job of converting complex carbohydrates (including celluose) into
-> ethanol. Evidently the project is far enough along that there are plans
-> to build a plant in New York, to produce 15(?) million gallons of ethanol
-> per year from paper mill sludge.
->
-> Now, let's hope the bacterium doesn't get loose in the environment, or
-> that it requires something to live that's found only in the culture tanks. :-)

-Well yes I guess that could be a problem, but if most attempts to grow
-microorganisms in "megaculture" offer any lessons then just the opposite is
-more likely.

One method that's been proposed to reduce the risk of genetically modified
microorganisms getting out and causing trouble is to use as a base stock some
tailored or selected organism that in order to live requires trace amounts
of some organic nutrient that's cheap to produce but which isn't found in
nature. I don't know to what extent this has actually been implemented.
Bacteria sometimes exchange genetic information, so it requires some
cleverness to come up with a nutrient requirement that's very unlikely to
be circumvented by a simple genetic swap with a wild microorganism.

-Usually what happens is that the cultures become contaminated with
-something far more competitive than the "special bug"  and the special bug
-just gets killed off by the competition.  Alternatively the special bug may
-grow competitively only under very narrowly defined conditions. Such
-conditions are quite hard to maintain with a heterogenous feedstock like
-forest products.  Also variables as simple as temperature control are not
-always easy to maintain between for example--winter and summer.  I would
-like to hear comments from the people who make antibiotics by fermentation
-on the probability of success here.

Also relevant - bacterium-produced human insulin is now readily available.
I don't know the relative prices.

-It is a very long jump from the lab to tons and tons of paper pulp which
-may be none too sterile. This particular dream (cellulose ---> ethanol) has
-been around for a long time.  I, for one, will believe it when someone
-actually makes a buck on it.

I should have listened to the report more carefully - I was driving, and
couldn't really take notes. I believe one point that was emphasized was
the wide assortment of junk the bacterium will eat. (I don't know whether
the material has to be sterilized first.) The plans for building a conversion
plant seemed pretty definite.

I brought this up in reference to the discussion on Earth resources vs
space resources, but I suppose exotic genetically altered organisms could
be important in recycling and in setting up working ecosystems in space.

John Roberts
[e-mail]

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

Date: Mon, 4 Jan 1993 21:11:23 GMT
From: "John S. Neff" <[e-mail]>
Subject: Fabrication (was fast track failures)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas Clarke) writes:
>From: [e-mail] (Thomas Clarke)
>Subject: Fabrication (was fast track failures)
>Date: Mon, 4 Jan 1993 20:24:21 GMT
>In article <[e-mail]> [e-mail] (Gary Coffman)
>writes:
>> In article <[e-mail]> [e-mail] (Edward
>V. Wright) writes:
>> >
>> Most engineering *is* paperwork, or workstation work today. Otherwise
>> it's just tinkering on a wing and a prayer. You have to bend metal to
>> *test* your engineering, but bending metal *isn't* engineering. It's
>> fabrication done by tradesmen.
>
>I can't let this go by.  This is a common attitude in America.  It
>leads to low pay for production engineers and inefficient production
>methods etc. etc.  Result is the current economic morass with most
>production going overseas.
>
>I think engineering must consider how something is to be made.  The
>most elegant design is useless if it can't be manufactured.
>Knowledge of what can be made is obtained by bending metal, or
>at least by interacting with those who do.
>
>This probably has nothing to do with space.  But then maybe it
>has a lot to do with why no really new space rocket designs have
>come out in the last 30 years except for the star-crossed shuttle.
>--
>Thomas Clarke
>Institute for Simulation and Training, University of Central FL
>12424 Research Parkway, Suite 300, Orlando, FL 32826
>[phone], FAX: [phone], [e-mail]
It has a lot to do with the manufacture and launching of ELVs.
The FSU have a highly automated system for the checkout and launching
of ELVs that has been used, for example, to launch payloads for growing
crystals in a microgravity environment. This is probably the most cost
effective system for such research presently available.

Because the FSU planners knew they were going to launch a large number of
these vehicles it was worthwile for them to spend the time and money on
automation and reducing the cost of manufacture. When you have just a
few vehicles they can be built like Rolls Royces. Our problem is that
we do not have a consistent space policy with respect to the number
and types of launch vehicles.

During the Reagan administration space policy was formulated by an
Inter Agency Group which had almost the same membership as the
National Security Council. Under the Bush administration VP Quayle
was in charge of space policy, and under the Clinton administration
Gore may be in charge. There is no reason to believe that the Clinton
administration will follow the same policy as the Bush administration.

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

Date: 04 Jan 93  10:30:14
From: [e-mail]
Subject: Fiber optic umbilical
Newsgroups: sci.space

Putting a fiber optic umbilical on a remote sensing platform designed to
traverse rough terrain seems very odd to me.  Can someone explain to me why
this was done?  A few things come to mind such as eliminating the weight
required for a radio and associated power supply.  Also the fiber optic does
allow for high reliability and high speed data transfer.

I'm *not* throwing stones at the Dante folks.  I'm just doing some head
scratching and hoping someone will explain this to me.

Thanks.

--- Mark Perew  [e-mail]
--- Mark's Information Repository and Funtime Emporium (1:103/208.201)


--- Squish v1.00

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

Date: Mon, 4 Jan 1993 21:27:26 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Latest Pegasus news?
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>Yeah, I'm saying a factor of two isn't enough to cover the likely
>stretchout in the development timeline as problems appear. I said
>in the other post that realistic numbers based on other new spacecraft
>development programs would be a tripling of MacDD's projected base costs
>and a tripling of their projected development timeline. That would still
>be cheaper than the monsterous delays and costs of Shuttle development.

Oh?  What new spacecraft are you talking about?  Apollo came in on time
and under budget.  If the time line had been tripled, we wouldn't have
landed on the Moon until 1991.  (Assuming the project wasn't cancelled
in the interim, as it almost certainly would have been.)


>I think *everyone* agrees that the Shuttle development program was about
>as badly managed as is possible while still getting a working system in
>the end.

But, Gary, the Shuttle is the quintessential example of the engineering
management philosophy you espouse.  The ridiculous Rogers Commission
report to the contrary, the Shuttle program was not "success oriented."
It was a failure-seeking program if there ever was one.

As it turns out, both approaches work about equally well.  The success-
oriented approach generally produces success.  The failure-seeking
approach generally produces failure.  Not a bad result in the eyes of
government employees for whom failure and delay spell lifetime job
security.  The only thing is, some of us really prefer success.



>I think comparisons to new airliner construction, such as the references
>to the progression of the 7xx series, is bogus because SSTO is attempting
>something no other craft has ever done,

Bogus right back at you, dude.

Every aircraft is designed to do something no other aircraft has done
before.  If an existing aircraft could do the same job, no one would
bother designing a new one.

>with an engineering team that has no experience with similar reusable
>spacecraft to draw on.

Next to Boeing, McDonnell Douglas's engineering teams probably have
more experience designing commercial aerospace products than any
company in the world.  Practically all of them reuseable.

I can almost hear you sucking breath every time you type the phrase
"reuseable spacecraft."  Strangely enough, you don't have the same
reaction to the phrase "reuseable aircraft."  Perhaps because you
don't know enough history to realize how much engineering and development
the first commercial aircraft required.  Or perhaps you know how silly
you'd sound if you spoke about aircraft development in the same apocolyptic
terms.  But mainly, I think, it's just the technological superstition,
which NASA has helped to instill, about anything connected with "space."
After so many years of seeing the way NASA spends money, you believe
there's just *got* to be a good reason for it; anything connected with
space must be at least an order of magnitude more difficult to do.  When
you hear that a vehicle is going to operate in space, without any air
outside, the superstition takes over, and you believe that the principles
of engineering that govern other aerospace systems don't apply.

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

Date: 4 Jan 93 23:54:56 GMT
From: Pat <[e-mail]>
Subject: Let's be more specific (was: Stupid Shut Cost arguement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>
>>        Shuttle could have lower costs then  NASA currently has,
>>        but it still needs a tremendous infrastructure.  The OPF,
>>        the VAB, Tilting bay,  the crawler/transporter.  Launch towers.
>>
>
>         Pat, the SLC-6 facility at Vandenberg did not have a VAB,
>         "tilting bay" (that's ths same as the VAB, though) or a Crawler.
>         SLC-6 reversed the action at the Cape's Complex 39. At 39,
>

Of COurse,  given that SLC-6 cost about 5 billion dollars, and was unable
to fly shuttles,  i would call that tremendoous infrastructure.

SLC-6 should have had some people shot for that one.

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

Date: 4 Jan 93 21:48:19 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Let's be more specific (was: Stupid Shut Cost arguements)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>>Which is indeed half the battle. But since you back Shuttle no matter what
>>it costs, I don't see your point.

>I back Shuttle because it's flying *now* and nothing else flying *now*
>has it's capabilities at *any* price.

I say again, since you back Shuttle no matter what it costs what's your
point?

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------110 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 4 Jan 93 22:41:34 GMT
From: "Wailer at the Gates of Dawn" <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

    I think this is a GREAT idea and that NASA should market MORE space items
to help finance its budget.  Whats the approx cost per pound of moon rocks
anyhow?

--
The Wailer at the Gates of Dawn              | [e-mail]       |
Just who ARE you calling a FROOFROO Head?    |                             |
DoD#0667  "Just a friend of the beast."      | [e-mail]      |
2,3,5,7,13,17,19,31,61,89,107,127,521,607....| [e-mail]        |

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

Date: Mon, 4 Jan 1993 21:56:33 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Overly "success" oriented program causes failure
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>Since *your* failure oriented system is totally your own strawman invention
>out of whole cloth, I won't bother to address it further.

My own invention?  Really, Gary, you're being too modest.

Practically all government agencies are failure-seeking systems.
Remember when the US Government said, "Give us a billion dollars
and we'll solve all the problems in American education?"  They
didn't, of course, but that didn't stop them from getting another
billion dollars, and another after that, and more after that.

Government agencies grow -- "succeed" -- by failing to solve
the problem they were set up to solve.  The last thing any
bureaucrat wants is to *really* solve the problem and put
himself out of a job.

Although this behavior originated in the social programs
side of the Federal government, it has now penetrated to
other agencies as well.  It's no surprise that it now takes
20 years to procure a jet fighter -- that means that a military
procurement officer can spend his entire carreer at the Pentagon
and retire in the same program.  Most of that time (and money) is
not spent in actual development, but in paper studies,
evaluations, and reviews.

The Space Shuttle was another example of a failure-seeking program.
The budget grew to just the point where it equalled the number of
dollars NASA needed to keep all its labs and offices open.  When
that happened, the goal became to keep the Shuttle development
program going as long as possible.  Finishing the program would
have been a disaster.

Of course, the Rogers Commission, headed by a State Department
carreer bureaucrat with no knowledge of engineering or technology,
didn't say that.  Instead, they blamed NASA -- as you blame NASA --
for being too "success oriented" (!) because somewhere along the
line, someone, somewhere actually took a chance to get the thing
to work.



>I gave an example of a "success" oriented program that went sour
>for the typical reason. If you want a megaprogram that came in on
>schedule and on budget despite thousands of engineering change
>orders during development, I'll point you to GM's Saturn line
>of automobiles.

The Saturn project wasn't success-oriented?  That would sure
come as news to GM!


>That's because the most likely developmental bottlenecks
>were identified in the planning process and allowance made in
>the Pert charts for alternative workaround development time and
>money.

I've got news for you, Gary.  Those Pert charts that you are
so fond of were invented for (boo, hiss!) success-oriented
Polaris-missile program.  Good engineers always expect problems
to arise during a project.  If possible, they plan for them in
advance.  If not, they handle them when they crop up.  The difference
between you and your personal devil, Dr. Wernher von Braun, is
not that you are a better, more careful engineer, as the success
of Project Apollo and every other von Braun program demonstrates,
but that he had imagination and vision too.

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

Date: Mon, 4 Jan 1993 21:18:00 GMT
From: PETER YASUDA <peipyy@robots>
Subject: Space List Flame Wars
Newsgroups: sci.space

In article <[e-mail]>,
[e-mail] ("Phil G. Fraering") writes...

>\I subscribed to this list in order to try to inform myself about the latest
>/news about US and other coutnries' space programs.  I thought that this would
>\be a list of technical discussions, not a religious debate that has turned
>/into ad hominem attacks and flame wars as virulent as any I've seen in the
>\religious news groups.  Then I see things like this, from Herman Rubin:

(excerpts of rantings deleted)

>1. Henry Spencer's little excerpt isn't political ranting but a
>   good summary of the facts. If you don't think so, you need to
>   look at the background of the COPOUS Treaty.

Great!  Let's degenerate this thread into a flame war on what
constitutes ranting.


>2. Currently our space programs are run mainly by the government,
    ...(unrelated stuff deleted)
>   of the situation." The people trying to push this off into
>   other newsgroups, which are accesible neither for posting
>   nor reading purposes to much of the internet population, are
    ...(more deleted)

OK, if the problem is that some people don't have access to the other
newsgroups suggested by the originator of this thread, I suggest
either of the following solutions:

1.  Move the offending threads to a new newsgroup (sci.space.advocacy)
    or create a sci.space.news or sci.space.dispassionate.discussion.

2.  Use meaningful subject lines.

The latter would be good practice with or without the former.  It
would be a lot easier to sift through postings if the subject lines
reflected the actual topic.  For (just one) example, the "Re: Latest
Pegasus news?" thread managed to stay on the topic for about two
postings before turning into the same discussion that seems to occupy
half the threads in this newsgroup.

Would it be too much trouble to change the subject line once a thread
has moved off to an entirely new topic?

Changing "Terminal velocity of..." to "Stupid Shut Cost arguements..."
is an excellent example of what I'd like to see.

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

Date: 4 Jan 93 21:13:12 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: SSTO vs 2 stage
Newsgroups: sci.space

In <[e-mail]> Graydon <[e-mail]> writes:

>>I understood that too.  Perhaps you did not understand what I meant
>>when I said, if there are enough heavy cargoes to justify a new
>>vehicle, it would be more cost-effective to build a larger SSTO
>>than a two-stage kludge?

>Rather depends on how many heavy cargoes there are, doesn't it?

No, I don't think so.  Building and testing a new two-stage vehicle
would be more expensive than building and testing a new one-stage
vehicle.  So costs would be greater no matter how many, or how few,
payloads you spread them out over.


>As I understand it, the point to an SSTO is to make expendables
>non-cost effective.  So there *won't* be another vehicle fairly
>soon after DC-1's get flying in numbers if they work as advertised.

I don't think Boeing gave up when McDonnell Douglas introduced
the DC-3.  If one company demonstrates a successful space
transportation system that makes money, other companies
won't let them have the market all to themselves for long.


>If there's one or two heavy cargoes a year, Bruce's quick and simple
>second stage might make a great deal more sense than scaling up
>an SSTO design by a factor of five, which I would expect to be quite
>difficult, since it's a complete re-design and probably needs new
>engines.

Bruce's "quick and simple" concept requires *two* new designs.
You couldn't just put 5x the cargo into an existing DC-1.  Unless
it was unusually dense, it wouldn't fit into the cargo bay.  Even
if you could, the vehicle's balance would be off.  So you're talking
a major redesign, then component testing of both the first and second
stages, then testing both the first and second stages together....

And I can't understand why a larger SSTO would need new engines
while a TSTO with a comparable liftoff weight wouldn't.

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

Date: Mon, 04 Jan 93 23:23:11 GMT
From: Doug Mohney <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

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

>BTW, the team evaluating Soyuz has finished its work. They concluded that
>there is no reason Soyuz couldn't be used as ACRV.

> It should also be
>possible to use Soyuz on an Atlas or Titan for US manned space.

They didn't study the latter possibility.

And if you're going to be a tightwad, why don't we just contract out launch
services to the Russians, for that matter? It would save us all that money
for integrating Soyuz on an Atlas or Titan, and obviously would be much cheaper
to pay Russian engineers than American ones....


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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

Date: 4 Jan 93 22:25:41 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Who can launch antisats? (was Re: DoD launcher use)
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>Technically possible, but militarily dangerous. You've just escalated
>a brushfire conventional war into a nuclear exchange.

Oh?  So what are you going to do about it?  MAD -- the aptly named
legacy of Robert McNamara -- is still in effect.  If you retaliate
by launching a nuclear strike against your enemy's territory, he can
do the same to you. Are you prepared to sacrifice millions of your
citizens to avenge the loss of one spy satellite?

I didn't think so.

You might retaliate by attacking your enemy's satellites, but if
he started the ASAT battle, it's because he decided he has less
to lose than you do.  (And if you're the United States, he's almost
certainly right.)

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From: Henry Spencer <[e-mail]>
Newsgroups: sci.space
Subject: launcher costs by type of economy
Message-Id: <[e-mail]>
Date: 4 Jan 93 20:34:54 GMT
Article-I.D.: zoo.C0CJu8.6sr
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Organization: U of Toronto Zoology
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In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>Well, Gary, some of us have the theory that free societies are
>>more efficient than "command economies."
>
>Then our launchers should be cheaper than theirs...

Gary, are you really suggesting that "our" launchers are built by free
enterprise?  The Western launcher industry *is* a command economy!  Some
35 years after it began operation, the very first private-venture launchers
are just starting to appear... and they're not coming from the mainstream
launcher industry.

I agree that, other things being equal (an important precondition!), free
societies are more efficient than command economies.  Nobody has yet tried
building a space program on free enterprise.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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End of Space Digest Volume 15 : Issue 633
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