Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_9/V16NO906.TXT

Text File | 1993-08-03 | 31KB | 700 lines

Space Digest                Thu, 22 Jul 93       Volume 16 : Issue 906

Today's Topics:
                             ACRV return
                        cheap space computers
                              Clementine
                      COOKIE CUUTTER PROBES (WA
            DC-X Prophets and associated problems (3 msgs)
                       DC-X thermal protection
                       EJASA Network Addresses
                  GPS in space (was Re: DC-1 & BDB)
     Head NASA Select Guy (was Re: NASA SELECT  and scrambling.)
              Hubble SOlar Arrays,  How'd they fould up.
              Hubble solar arrays:  how'd they foul up?
                    Info about old Diamant wanted
                          Perseid publicity
          Russian/French crew set to leave Mir space station
                Very basic questions about dark matter
              Waste Management aboard Skylab and Shuttle

    Welcome to the Space Digest!!  Please send your messages to
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 20 Jul 93 17:48:36 GMT
From: Ralph Buttigieg <[e-mail]>
Subject: ACRV return
Newsgroups: sci.space

Original to: [e-mail]
G'day [e-mail]

17 Jul 93 19:18, [e-mail] wrote to All:

 hte> Look at the parts of the globe within 28.5 degrees of the equator.
Lots
 hte> of ocean, lots of desert and jungle, lots of underdeveloped countries
 hte> with slightly-dubious governments.  You'd really like to aim an
emergency
 hte> return at somewhere like the great plains of North America or the
Russian


The primary return area for the ACRV is central Australia. Big, dry and
flat. With resonably non-dubious governments.There were NASA people out here
late last year checking the facilities out.

ta

Ralph

--- GoldED 2.41+
 * Origin: VULCAN'S WORLD: Astro/Space BBS [phone]  3:713/635
(3:713/635)

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

Date: 21 Jul 93 22:13:02 GMT
From: Henry Spencer <[e-mail]>
Subject: cheap space computers
Newsgroups: sci.space

In article <22k5aq$[e-mail]> [e-mail] (Pat) writes:
>>A much bigger practical problem is that the off-the-shelf hardware is
>>designed to be air-cooled...
>
>WOuldn't Mil-SPec Rad Hardened Commercial chips resolve this problem?
>I think a lot of USAF  and USN stuff have to either cool on a sealed
>system,  or use low pressure...

No, rad-hardened chips don't help this at all.  They have exactly the
same cooling problems as commercial chips.  The cooling problems for
military gear are solved at the board or box level, not at the chip
level.  It boils down to providing a flowing fluid to carry heat away,
providing sufficiently wide conductive paths to conduct it away, or
making sure that components can radiate well enough to keep their
temperatures within limits.  The reason why Earth-based systems all
use flowing-fluid cooling (with air, freon, whatever) is that it's
a whole lot easier than the alternatives.

It can be done, as witness the Apollo electronics -- all of it
vacuum-rated because the airlock was the whole capsule -- but it
requires very different design from run-of-the-mill commercial
hardware.
--
Altruism is a fine motive, but if you   | Henry Spencer @ U of Toronto Zoology
want results, greed works much better.  |  [e-mail]  utzoo!henry

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

Date: 22 Jul 93 00:33:23 GMT
From: Dan Durda <[e-mail]>
Subject: Clementine
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dan Durda) writes:
>
>I have seen photos of the LM's taken by panoramic cameras aboard the CM's.
>Particularly, the CMP on Apollo 15 observed the landing sight with 20x-30x
>gyro-mounted binoculars and I believe he was able to see the LM itself. He
>certainly noticed that there was a bright halo about 150 meters across,
>which was most likely material disturbed by the exhaust plume. This was
>discussed as a good indicator for helping to locate the position of the LM
>on future flights. The LM and LRV parked right next to it are visible as
>bright spots with shadows on a 50x enlargement of the panoramic camera
>photgraphs. Pretty interesting...
>
On the first pass over the Apollo 14 landing site the CMP noted a white spot
that was obviously foreign to the lunar surface. When he saw the shadow of
the LM he realized he had indeed identified the LM. The next day the shadow
had dimished quite a bit, but he could still identify the LM, and by that
time the ALSEP package had been deployed. He could easily see the glint
coming off the ALSEP!

--Dan

--
Daniel D. Durda
Department of Astronomy
University of Florida
[e-mail]

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

Date: Wed, 21 Jul 1993 21:21:04 GMT
From: Zvi Lev <[e-mail]>
Subject: COOKIE CUUTTER PROBES (WA
Newsgroups: sci.space

Steve Linton ([e-mail]) wrote:

: |> So back to my crazy idea - imagine an EISA compatible spacefhcraft bus,
: |> so that any existing card could be just plugged in.
: |> As pat says, sure, you have to check it for enviro etc, and probably
: |> some won't work. But I believe most will.

: I think you're wrong. I think roughly NONE will. The space environment,
: especially ine LEO (where you clip the Van Allan belts occasionally, let alone in
: Jupiter orbit or Mercury orbit, is incredibly hostile to electronics. Also
: they're way too heavy.

I do not agree. Space environment in LEo of below 1000 Km (where most interesting
things happen for Leo sats) is not very radiative ('hostile' sounds bad to me -
it meand one doesn't know what it does , which is not the case at all). For
orbits near Jupiter etc. you may be right. But let's concentrate on
the 'close by ' environment for now. Weight is of course not a problem , and
could not possibly be - today's electronics can do everything the electronics
in probes/sats did 5 years ago for a fraction of the weight/power consumption,
(and of course, power consumption IS WEIGHT). I'll bet any laptop size PC
nowadays has more power than the most powerful space computer flown
until 2 years from now. ANd of course it's weight (including power consumption)
is totally negligible in the weight of the sat. The weight added in
making the cards themselves stronger , and wiring for heat sinks, is also
not a major problem. On the other hand, there is the big weight saving
of having all your major instruments on a single bus, instead of having
for each of them all the communication circuitry, power supplies etc. This
part is the largest in any stand alone box.

Back to 'hostile environment' - cpu's etc do not get eaten alive in
space by green aliens. they get SEU'd (Single Event Upset), latch up etc.
Sometimes they can get out of their sockets if shaken badly, or
fouled up by excessive outgassing. Radiation effects one can predict
without testing (standard procedure for any sat). As to the rest - nothing
more than is required of any military/flight hardware. Again, I too
believe there are problems - such as taking out the massive amounts of
heat produced, and probably standard plugs are not all that good under
massive shaking/outgassing.

Again, this is of course not a simple way to go. Anyone who knows
about electronics and may enlighten me with facts about it?
Zvi ('honey, I flew my PC to satrun') Lev

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

Date: Wed, 21 Jul 1993 22:28:19 GMT
From: Edmund Hack <hack@l44c4-2>
Subject: DC-X Prophets and associated problems
Newsgroups: sci.space

Allen W. Sherzer ([e-mail]) wrote:
[regarding the "ease" of man-rating the DC-1]
: Your putting the cart before the horse. FAA certifies aircraft based on
: operational testing. Spacecraft are man rated largely based on paperwork.

I beg to take exception with you here. With the exception of Shuttle,
all US launchers and manned spacecraft had a fair amount of flight
and/or ground testing. As I recall, severe pogoing by at least one stage
of the Satrun V DQed it from being man-rated at first. Fortunately the problem
was diagnosed and fixed. The entire Apollo CSM stack was thermal vacuum
tested at JSC in week-long tests with a crew inside. Similar tests were
made on the LM. Practice shots of the Mercury and Gemini systems were
also made. The CSM gas mixture was change in life support.

Man-rating is not just adding a few escape and safety packages to a
booster. It includes g-level and jolt limits, acoustic load limits,
etc. Note also that the level of maturity in aircraft design and
spacecraft design are not anywhere near each other, so the FAA has a
much easier task to perform - the accumulated wisdom of the century is
available. Note also that despite the certification tests, engines fall
off of their mounts, hydro power is lost due to single point failures,
flaps deploy unexpectedly, the general aviation aircraft business is on
life support and slipping fast, etc.

: There is no reason a DC couldn't be certified just like any airliner.

As I stated above, that may or may not be true.

[stuff deleted]

: Sure
: it will be more dangerous than an airliner but so what? We will never get
: the experience you are talking about with Shuttle, there simply isn't
: enough money in the world.

Here is what the _real world_ test on "safety" will be:

Will my insurance policy pay off if I die in a DC-1 accident while
flying in one as a paying passenger?

BTW - I fully support the BMDO's SSRT project and have been sending
faxes and making calls as the calls for same have come.
--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"Everybody wants prosthetic foreheads on their real heads"
"I'm not an actor, but I play one on TV."

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

Date: 21 Jul 93 23:23:59 GMT
From: Paul Dietz <[e-mail]>
Subject: DC-X Prophets and associated problems
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dave Michelson) writes:

> I feel compelled to note that the Space Shuttle that NASA got is *NOT*
> what they wanted.  It wasn't even their second choice.  Or their third.
> When all the money was counted, and after the Air Force imposed its
> requirements, the shuttle we have now is all that was left.


This doesn't excuse NASA.  The fundamental problem was that it made no
sense to develop a reusable shuttle unless there was a lot of traffic
over which to amortize the development.  So NASA had to get customers
whereever it could, including from an ambivalent military.  If they
had not promised to meet the military requirements, the pretense that
the shuttle would pay for its development would have been
unsustainable, and it would have been cancelled.

Having prostituted itself, NASA can hardly complain about its virtue
being damaged, or about being made to keep its word about keeping
development cost low enough to be repaid by supposed cost savings.

What is most galling about all this is that cheaper, simpler
alternatives that could have reduced launch costs considerably were
under development in the 1960s.  For 1/2 the price of running the
shuttle for 1 year (in inflation-adjusted dollars) we could likely
have had a Big Dumb Booster that would launch shuttle-size payloads
for 1/10 to 1/20 the cost of the shuttle.  The development risk would
have been much lower.  It would not have been as much of a jobs
program for California, though.

    Paul F. Dietz
    [e-mail]

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

Date: 22 Jul 93 00:30:01 GMT
From: Dave Michelson <[e-mail]>
Subject: DC-X Prophets and associated problems
Newsgroups: sci.space

As a point of comparison, the Shuttle and the B-1/B-1B bomber were developed
in approximately the same time frame and somewhat similar circumstances.

While the Shuttle is disappointing for all the reasons previously noted,
the B-1B is arguably an outright failure.  Perhaps I'm being to lenient
on NASA but I figure they did rather well considering all the interference
and second guessing from without.  Hindsight is 20/20....

Having said that, DC is clearly being developed in a different time frame
and under a different set of circumstances.  Let's hope that it works out.
There are many reasons that it might.

--
Dave Michelson  --  [e-mail]  --  University of British Columbia

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

Date: 21 Jul 93 22:35:08 GMT
From: Henry Spencer <[e-mail]>
Subject: DC-X thermal protection
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>>It [crossrange] *is* a silly requirement, for an SSTO.
>
>Depends on how much it costs. I agree it was silly for Shuttle since it
>added so much cost and weight. But for DC it doesn't seem to be that big
>a problem due to the MDC MARV work.

This is a debatable point; the alternate view is that they had to design
their whole vehicle around achieving a relatively unimportant capability,
at the cost of compromising other characteristics.  (For example, much
of DC's skin is potentially in "windward" positions and requires good
thermal protection.  In an orthodox Bono SSTO, like the GD proposal,
most of the skin is in a "lee" position.  Thermally, DC is "all nose",
and the nose is the worst case for heating.)  (For another, the whole
tricky business of the flip maneuver is dictated by nose-first reentry.)

>>Making a landing after a
>>single polar orbit is no big deal, assuming you aren't stupid enough to
>>launch from the West Coast...
>
>... Consider two SSTO's one with crossrange and another
>without. Both have equal operational costs and both require 5 ground days
>of servicing to fly again. Both take off from White Sands Spaceport
>to polar orbits and return after ASAP to pick up another payload.
>
>The first SSTO is back at port 90 or so min. after launch and flys five
>days later for a total of 73 flights per year. The second SSTO because
>it lacks any crossrange takes maybe a day to get back to port so it
>only flies 61 times a year...

Why does it take a day to get back to port?  Land at a suitable port
1500km to the west and do a suborbital hop to get back.  The return
hop is short and flown at very light weight, so you don't need major
servicing before doing it.  The extra cost and delay should be slight.
Covering that 1500km as a low-speed suborbital ballistic hop is a whole
lot easier than doing it with lift at reentry speeds.

That's if you insist on flying the mission as one orbit.  In civilian
applications, you are probably better off waiting 12 hours for a pass
over White Sands.  Among other things, this will let you take your
time with orbital operations, instead of having to scramble through
them in 30-40 minutes (you need to make retrofire about half an orbit
before landing, remember).
--
Altruism is a fine motive, but if you   | Henry Spencer @ U of Toronto Zoology
want results, greed works much better.  |  [e-mail]  utzoo!henry

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

Date: Wed, 21 Jul 1993 21:55:11 GMT
From: Larry Klaes <[e-mail]>
Subject: EJASA Network Addresses
Newsgroups: sci.astro,sci.space,sci.misc

    There are two main network addresses for writing to the EJASA:
    Mine (see end of message) and a general ASA address - [e-mail]
    There is also an ASA BBS - [phone], 300/1200/2400 Baud

    If you want to send regular mail to the ASA:

        Astronomical Society of the Atlantic (ASA)
        P. O. Box 15038
        Atlanta, Georgia  30333-9998
        U.S.A.

        or telephone the Society Recording at [phone] to leave your
    address and/or receive the latest Society news.

        Larry Klaes  [e-mail]
             or - ...!decwrl!verga.enet.dec.com!klaes
                 or - [e-mail]
                     or - [e-mail]

             "All the Universe, or nothing!" - H. G. Wells

        EJASA Editor, Astronomical Society of the Atlantic

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

Date: 21 Jul 93 19:16:22 GMT
From: Gary Coffman <ke4zv!gary>
Subject: GPS in space (was Re: DC-1 & BDB)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <229kmb$[e-mail]> [e-mail] (Pat) writes:
>>Why is it, cheaper for me to drive to work in DC (Home to the best
>>public transit system in AMerica)  then to take metro.
>
>Bad management. :-)  I assume "AMerica" refers to the country, not the
>continent -- Toronto has the best public transit system on the continent,
>and it's certainly the cheapest way for me to get to work, if you exclude
>bicycling.  (Might be different if I needed a car for other things, but
>in Toronto you don't.)

Bad management is certainly true, fares don't pay a tenth of MT costs,
yet it's still expensive. Also bad routing, bad scheduling, no end to end
service for most trips, and the ever present bugaboo of crime and lack of
privacy and feeling of loss of control that mass transit engenders. Mayor
Maynard Jackson wants to make Atlanta's MARTA *free* to encourage use.
Ridership has been declining even as more of the system comes on line.
The MARTA board even decided not to open one recently completed section
because the ridership had disappeared in the period between start of
construction and completion. Where will the money come from to replace
the fares? Why from Uncle Sap of course, where 90% of MARTA funding
already originates. I'd like to say thank you to you folks in Iowa
for paying for our nice French built choo-choos. (Note: Rohr Industries,
the largest railcar manufacturer in the world, is 30 miles outside
Atlanta, but they didn't get the contract because Maynard wouldn't
get a trip to Paris out of that.)

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 21 Jul 1993 18:00:25 -0400
From: Pat <[e-mail]>
Subject: Head NASA Select Guy (was Re: NASA SELECT  and scrambling.)
Newsgroups: sci.space

 nothing prevents a local cable channel from shoving a commercial
in along the SELECT programming.  Select is free,  i don't believe
it forbids commercial activity.

pat
--

God put me on this Earth to accomplish certain things.  Right now,
I am so far behind, I will never die.

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

Date: 21 Jul 1993 18:05:35 -0400
From: Pat <[e-mail]>
Subject: Hubble SOlar Arrays,  How'd they fould up.
Newsgroups: sci.space

Everyone knows in aching detail  the who's  how's and whatfor's
of the Main mirror problem of the HST.  However a larger
problem  has received very little attention.   That is the
Solar Array vibration problem.  THese were fabricated  under
contract to ESA by British Aerospace?  and now  spend
about 20%  of the mission time shaking the damn thing
around enough that guidance is disrupted.

What i was wondering is how could this kind of design flaw
sneak past any sort of reasonable test procedure?  I would think
that thermal/vacuum testing  would show this kind of behavior
of the solar arrays?

what happened.   did NASA not spec out any testing?  or
did the ESA people bury the problem?

pat
--

God put me on this Earth to accomplish certain things.  Right now,
I am so far behind, I will never die.

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

Date: Wed, 21 Jul 1993 22:39:29 GMT
From: Leigh Palmer <[e-mail]>
Subject: Hubble solar arrays:  how'd they foul up?
Newsgroups: sci.space

In article <22kejf$[e-mail]> Pat, [e-mail] writes:

>What i was wondering is how could this kind of design flaw
>sneak past any sort of reasonable test procedure?

Good grief, man. How can you ask such a question, even
rhetorically, when the most conspicuous related example
of our time is the mirror on the same spacecraft?

The answer to your question is, no doubt, the same.
There was not a reasonable test procedure in place, or
if there was, some committee decided not to believe its
negative results, which amounts to the same thing.

Leigh

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

Date: 21 Jul 93 19:17:42 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Info about old Diamant wanted
Newsgroups: sci.space

In article <[e-mail]>, andreas@black_uster (Andreas Forrer) writes:
> I'm looking for ANY kind of information about a French rocket called
> "Diamant BP-4" from 1975. Any hint is welcome, including pointers to
> possible sources.

Hate to post this feeble hint, but Andreas's address seems un-reply-able.

I think there was a review of French launchers in one of the history
issues of *Journal of the British Interplanetary Society* within the
past two or three years.

In our town, the U. of Chicago and Northwestern University libraries
get *JBIS*.  Possibly the Adler Planetarium does too.  Don't have my
own collection organized well enough to find it-- sorry!

> ------------------------------------------------------------------------
> Andreas Forrer, Swiss Bank Corp., 141 W. Jackson Blvd., Chicago, IL 60604
> If you believe, I'm speaking for my company, then you really have no clue
> what a bank is all about.

Andreas, *please* put your Internet address in your signature.  Your
mailer is breaking the "From:" address in the headers.
--
     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     [e-mail]
   -   -       Internet:  [e-mail]
     ~         SPAN/Hepnet:      43011::HIGGINS

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

Date: 21 Jul 93 18:43:56 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Perseid publicity
Newsgroups: sci.astro,sci.space

In article <[e-mail]> Leigh Palmer <[e-mail]> writes:
>I do like to watch with other people, but there seems to be little
>point to assembling vast numbers, unless by so
>doing you can evengelize successfully about light polution. I have
>given up on this cause in cities like Vancouver. Too many of my congeners
>are Yahoos who will never care. I wish you success, Mr. Ryan. If you
>succeed in raising public support for, say, shielded outdoor lighting
>I'll be impressed. California's ruined. I've failed miserably here. Maybe
>I should emigrate to Ireland next.

So gather your astronomer buddies and buy a Pacific island. If Marlon
Brando can do it, so can you and a few of your friends. When your nearest
neighbor is a thousand miles away, it can get real dark. Dull, no night
life, you say? Well, them's the breaks, as the Yahoos say. A neon sky
is more to their liking. It makes it easier to see the mugger sneaking
up to rob you.

Gary

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Wed, 21 Jul 1993 17:08:44 -0700
From: Glenn Chapman <[e-mail]>
Subject: Russian/French crew set to leave Mir space station

    Onboard the Mir space station the Russian/French mission is preparing to
depart for a landing on July 22.  Long term cosmonauts Gennadiy Manakov and
Aleksandr Polishchuk, who arrived at Mir on Jan. 24th, will be flying French
Spationaut Jean-Pierre Haignere in the older Soyuz TM-16 capsule. Manakov and
Polishchuk will have spent 174 days in orbit during this mission, while
Haignere will have had 22 days in orbit.  Manning the Mir complex will be
cosmonauts Alexander Serebrov and Vasily Tsibliev (mission commander).   They
are slated to do several space walks in September to modify the power systems
on the Mir space station.

     The International French video station TV5 has shown several news
conferences with the combined Mir crew, including one with the French Prime
Minister.  Interestingly for most of these a huge French flag was in the
backdrop.  These appeared to be broadcast from one of the large Star modules
extending perpendicular from the front ball docking adaptor of Mir.  Views
were show of the Soyuz TM-17 during from a window during one of the
conferences.

     In other news according to a Radio Moscow report on July 19th the US and
Russia reached an agreement on the selling of Russian space hardware to other
countries.  The problem arose over the sale of liquid hydrogen/oxygen rocket
technology to India for use in an upper stage.  This was considered by some
to violate the missile control treaty which prevents the sale of ICBM
hardware.  Russia will be allowed to sell upper stages, but not the
technology to build them.  Another agreement was signed in Washington on July
20, for cooperation in manned space missions.  This calls for the flight of a
Russian cosmonaut on the space shuttle, and an 1995 visit to Mir by a US
astronaut.  This second agreement was being held up until the Indian export
problem could be solved. (Radio Moscow and French TV5)

                                                       Glenn Chapman
                                                       School Eng. Science
                                                       Simon Fraser Univ.
                                                       Burnaby, BC Canada

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

Date: 21 Jul 93 20:14:34 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Very basic questions about dark matter
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
>Just have enough "S"s in you TLA! I surmise a SSS would
>be pretty much guaranteed $100 billion+

It would have to be. The SuperSonic Subway project from NY to LA is
a monumental undertaking, but it can get you there faster than DC-XYZ.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: 21 Jul 93 19:53:37 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Waste Management aboard Skylab and Shuttle
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Kennelmeister) writes:
>
>Fred is big(ish). There's anough room (figuratively speaking) to swing a
>cat inside.
>
>How about a centrifuge based toilet compartment?
>
>It wouldn't have to spin very fast - just enough to provide
>"artifical gravity" for the occupant and his/her waste products.
>It could be spun up after the occupant enters, rather than trying to
>have some complicated entry procedure...
>
>This would enable the use of fairly basic chemical toilets,
>until the basic issue of real zero-g toilets has been solved.
>
>This wouldn't be a viable shuttle solution for obvious reasons,
>but is there any reason it can't be used for larger installations?

Er, ever ride a dryer? The centrifuge would have to have a short
enough moment arm to fit inside, and that's short enough to make
you very sick. Blowing chunks while doing number 2 could be unpleasant.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Newsgroups: sci.space

From: Dave Michelson <[e-mail]>
Subject: Re: DC-X Prophets and associated problems
Message-Id: <[e-mail]>
Organization: University of BC, Electrical Engineering
References: <22jbtb$[e-mail]>
Date: Wed, 21 Jul 1993 21:12:05 GMT
Lines: 22
Sender: [e-mail]
Source-Info:  Sender is really [e-mail]

In article <22jbtb$[e-mail]> [e-mail] (Michael C. Jensen) writes:
>I feel compelled to note a historical similarity in recent posting to an
>event in the recent past, and hopefully help aviod a repeat. Currently,
>those DC-X/1 Prohpets are fortelling of a glorious time when the DC
>is flying. Cost per pound will be unbeleivably low. Man-ratings will be
>simple and easy. The system will be so remarkable as to completely
>revolutionize the world and all we know.. or at least something roughtly
>along those lines.
>
>Those that can, think back to the post-apollo days. A great mythical
>project was underway to produce the world's first cargo truck to space.
>There'd be 80 launchs a year. Hundreds upon hundreds of people would be
>able to fly into space. Cost per pound would be very very low. Reliabiity
>would be immesurable. Well, we got the shuttle.

I feel compelled to note that the Space Shuttle that NASA got is *NOT*
what they wanted.  It wasn't even their second choice.  Or their third.
When all the money was counted, and after the Air Force imposed its
requirements, the shuttle we have now is all that was left.

--
Dave Michelson  --  [e-mail]  --  University of British Columbia

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End of Space Digest Volume 16 : Issue 906
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