Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO360.TXT

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Date: Thu, 25 Mar 93 05:06:35
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #360
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 25 Mar 93       Volume 16 : Issue 360

Today's Topics:
    Aluminum, James Burke, and The Lost Secrets of the Ancients...
                     Artificial Gravity (2 msgs)
                         Canada Space Program
                            CRAF's budget
                            DC-X (2 msgs)
                        Earth Stop Rotating!?
             Flight time comparison: Voyager vs. Gallileo
                           gravity (2 msgs)
                           Hello Goldstone!
            Looting in Baikonur & Ukrainian Space Program
                         Lunar ice transport
         Predicting gravity wave quantization & Cosmic Noise
          Rocket clones: reduce risk of introducing new tech
                           SSF Redesign....
            SSTO: A Spaceship for the rest of us (2 msgs)
                         waste management...

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
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    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: Wed, 24 Mar 1993 00:15:46 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Aluminum, James Burke, and The Lost Secrets of the Ancients...
Newsgroups: sci.space,sci.materials

[e-mail] (Pat) writes:

> If aluminum was noted during roman times, then it indicates it needed
>even less of a technology base to extract then I guessed.  I guess
>Bronze age technologies could reach it.

Maybe, maybe not. The technology _I_ suspect was used has
basically only been found in ruins from the iron age...

Let me Speculate wildly:

>Probably the Indians
>or Arabs also had identified aluminum.  IT probably wasn't
>useful though given it's nearly difficulty to work.
>Plus other metals were much cheaper toe xtract and much
>better in their character.

It's not a question of whether or not a certian civilization had
the process; sometimes professional guilds, like metalsmithing,
had traditions that breached the gap between say the Romans, the
Greeks, and the Persians... they were almost half mystery cult,
and they guarded their secrets within their craft even more
jealously.

Which is why the knowledge eventually died out. They didn't believe in
sharing it. We can't read about a device called a "battery" one of
them thought up, (we've found them in archaeological excavations,
though) because he only told his apprentice, who told maybe his
apprentice, who spread it word of mouth only to other metalsmiths, and
then only the ones they trusted, because they were practicing the
ultimate fraud, which would be regarded through the centuries as being
as unatainable as the philosopher's stone. The great lost
philosopher's stone itself.

Alchemy. Changing base metals into gold. Of course, through history,
it also had the second meaning of "making base metals indistinguishable
from gold currency."

(I guess I could also mention here that that's also the reason so many
of the early natural scientists studied alchemy and also were
involved, at the same time, in the regulation of currency: Archemides,
Newton and Halley, etc.)


Basically, the process the Roman smith had used to extract the lump
of "gray metal" from was the same one we used today: electrochemistry.
And the reason he had to die rather than reveal it was that a large number
of his colleagues were probably using it to make "solid" gold objects
out of base metals of the right density and electroplating them.

For all we know, he might have told the emperor, who then killed
him to keep his mouth shut and the economy stable...

>pat

Well, there you have it. I don't know if the above speculation (although
the part about the batteries is true) is correct, but it seems likely
to me. It seems even more likely if you imagine James Burke doing it,
flashing back and forth between Rome, Elizabethan England, Napoleon III,
and Ancient Babylon, where some unknown mythohistorical figure on the
--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: 24 Mar 93 03:05:29 GMT
From: Henry Spencer <[e-mail]>
Subject: Artificial Gravity
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (neil storey) writes:
>Since it seems inconceivable that no-one has thought of this
>idea before, it would seem obvious that there must be some reason why
>this approach to artificial gravity [tethers] is unusable! ...

You've missed a point:  where is the *requirement* for it?  No current
US missions are up long enough for lack of gravity to be a serious
problem; indeed, *absence* of gravity is a requirement for many of them.

(In fact, the astronauts like free fall and aren't particularly interested
in artificial gravity.)

The idea gets serious discussion for things like manned Mars missions,
where the crew would be spending long enough in free fall for the
physiological effects to be worrisome.  Hooking two ships together
with a tether is the obvious approach.  It would be nice if there was
some level of gravity well below 1G that would minimize the medical
effects of free fall; unfortunately, we have no idea whether there
is one or not.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Tue, 23 Mar 1993 23:24:00 GMT
From: neil storey <[e-mail]>
Subject: Artificial Gravity
Newsgroups: sci.space

Over the years there has been much discussion in
the media concerning the physiological problems associated with long periods of
weightlessness. Periodically this re-awakens my puzzlement
about this problem since for many years I have wondered why
little effort seems to have been directed at artificially
generating gravity in space.

Since the film "2001" every school-boy has known that the
solution to the problem is simple (at least in principle). One
simply constructs a space station in the form of a torus
and then spins it at an appropriate rate such that
the centrifugal force (caused by the centripetal acceleration)
is equivalent to the force of gravity on earth. The force
experienced is proportional to the product of the radius of
the toroid and the square of its angular velocity.

I am, however, aware that there are some problems associated
with this idea, mostly arising from the presence of Coriolis
forces when any object moves radially within the torus. The effect of
these forces would be that an astronaut moving about within
the space-station would experience disconcerting lateral
forces which could be very disorientating. The magnitudes of
these forces are proportional to the angular velocity of the
torus and to the radial velocity of the moving object.
In order to overcome these
problems the torus must rotate slowly, and I believe that a
rotation rate of the order of 2 minutes per revolution is the
maximum thought to be allowable to prevent the astronauts from
being aware of their own rotation.
If one accepts this rate of rotation it transpires that to
achieve full earth gravity a space-station would need a radius
of nearly 4km.

Many people have pointed out the
impracticability of attempting to build such a large torus in
space when every piece must be shuttled from earth. However
this argument overlooks two important points: firstly that it
is not necessary to recreate full earth gravity in space, even
a fraction of this value would be of great benefit; and
secondly, it is not necessary to construct the complete torus
to simulate gravity, two small spacecraft linked by a cable
would have the same effect. The planned Russian mission to
mars would/will consist of two spacecraft. If these where joined
together by a cable and the resultant binary spun, both craft would
experience artificial gravity.

Clearly one factor in the viability of this solution is the
weight and volume of the required cable. I am no expert in
this field but my "back of an envelope" calculations indicate
that even using hemp rope is would be possible to carry in a
single space shuttle sufficient rope to link two space shuttles such
as to generate more than half of normal earth gravity. (I am
not however suggesting that hemp would be an ideal material
for use in space). I am sure that with the budgets available
to the space agencies a cable with suitable strength,
weight and other physical properties could be produced.

Since it seems inconceivable that no-one has thought of this
idea before, it would seem obvious that there must be some reason why
this approach to artificial gravity is unusable! I would be
very grateful to any readers who could throw some light on
this problem.

Neil Storey
Dept of Engineering
University of Warwick, U.K.

e-mail: [e-mail]

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

Date: Tue, 23 Mar 93 00:30:36 CST
From: "Norman P. Paterson" <[e-mail]>
Subject: Canada Space Program
Newsgroups: sci.space

[e-mail] (Joel Semeniuk) writes:

> I need information about the Canadian Space program.  Does anybody know where
> I can obtain information pertaining to jobs in the space program.  If anyone
> has any information that they can give me about who or where I can contact I
> would really appreciate it.  Thanks.
>
> Joel Semeniuk
> Computer Science III
> University of Manitoba
> Winnipeg, MB.
>
>

Hello, my name is Mr. Norman Paterson, president of PATERSON AEROSPACE
CO. located here in Winnipeg.  I can get you all the addresses you would
ever need, please phone me at my residence to discuss how I might help
you, and perhaps what you may have to offer also.
Good day.
Norm.
ph [phone]

[e-mail]
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607

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

Date: Tue, 23 Mar 1993 23:41:37 GMT
From: Henry Spencer <[e-mail]>
Subject: CRAF's budget
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Tom) writes:
>>CRAF was cancelled because it had overrun its budget massively, and Congress
>>was giving clear signals that this would not be tolerated.  This had nothing
>>to do with the manned/unmanned wars.
>
>I have a quibble:  FRED has overrun it's budget, but it lives.  Why the
>'selective prosecution', if it's not about manned/unmanned, or at least
>an effect of un/manned?

Because Congress gave CRAF/Cassini an absolute total overall budget cap
(with the stipulation that CRAF died first if there were overruns),
something that has not been done for most other projects, including Fred.

Few NASA projects, manned or unmanned, would survive to fly if they had
firm budget limits.  Overruns are a way of life for NASA space projects.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 24 Mar 93 03:07:02 GMT
From: Henry Spencer <[e-mail]>
Subject: DC-X
Newsgroups: sci.space

In article <[e-mail]> John R. Manuel <[e-mail]> writes:
>... I still have my question about re-entry: how is DC-Y*
>going to be able to re-enter the atmosphere without experiencing engine
>damage? If it assumes an Apollo-like attitude on re-entry...

It doesn't; it reenters nose-first.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Tue, 23 Mar 93 00:27:54 CST
From: "Norman P. Paterson" <[e-mail]>
Subject: DC-X
Newsgroups: sci.space

[e-mail] (John R. Manuel) writes:

> Are there any articles in Aviation Week, or somewhere similar, about DC-X
> that someone can refer me to? I'm curious to see the design of the thing
> and in particular, how it will manage re-entry and still be re-usable.
>
> -----------------------------------------------------------------------
> ---
> John R. Manuel
> [e-mail]
> 64-4-570-4024 (office)                           NIWAR Atmospheric
> Division
> 64-4-566-6166 (fax)                                 Wellington, New
> Zealand
> -----------------------------------------------------------------------
> ---

Yes there is one detailed analysis of DC-X in an issue of AW&ST I believe
six to twelve months previous.  Consult a magazine index at a library.
Norm, CANADA

[e-mail]
The Inquiring Mind BBS, Winnipeg, Manitoba  204 488-1607

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

Date: Tue, 23 Mar 1993 23:57:52 GMT
From: Tom A Baker <[e-mail]>
Subject: Earth Stop Rotating!?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (David Lai) writes:
>    I'm faced with a strange question.  What will happen to the
>climate, magnetic field, plate tectonics, and us if this happened??
>Any comments or suggestins?

Comment: That *IS* a strange question.  I hope it's hypothetical.

Suggest you see the H.G.Wells short story "The Man Who Could Work Miracles".
The movie derived from it is lame, though accurate.

A totally different angle is described in Larry Niven's story "One Face".

-----

In Well's story, the Earth *STOPS* rotating.  Like that.

Well, remember that we travel eastward at a big clip, depending on your
latitude.  Here around forty degrees north, it's about the speed of sound.
When the Earth stops, little things like people, buildings, mountains,
oceans, and the atmosphere just keeps on going.  The main character managed to
stop hurling through the air and got down to the ground safely just in time
to see the whole Atlantic Ocean come crashing in from the west.

------

In Niven's story, it's so many billions of years before the Earth stops due
to tidal drag or some such reason.  I can't say more without ruining the
ending, but it seems scientifically plausible.

tombaker

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

Date: 23 Mar 93 15:23:28
From: Steinn Sigurdsson <[e-mail]>
Subject: Flight time comparison: Voyager vs. Gallileo
Newsgroups: sci.space

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


   The first mention of Titan-Centaur I can find is the 1968 debate over
   whether Viking should be an austere Titan mission or a more ambitious
   Titan-Centaur mission.

I thought the original Viking concept (then named Voyager!?)
was for a _Saturn_ launched mission, with a seriously massive
lander? Was the first of the big cutbacks to NASA in the 68 or
69 budget?

|  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: Tue, 23 Mar 1993 22:29:02 GMT
From: Gary Coffman <ke4zv!gary>
Subject: gravity
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Jim Baker) writes:
>
>Acknowledging the fact that the earth has enough gravity
>to hold an atmosphere in place, and the moon (with about 1/6
>of earth's gravity) does not, how much gravitiy does it take
>to hold an atmosphere?  This is realizing it depends on the
>type of atmosphere, but I am looking for a general answer.

The criteria for holding an atmosphere is simple. The mean
free speed of the atmospheric constituent molecules must be
below escape velocity. Lighter molecules, and hotter molecules,
have higher mean free speeds. And the converse is also true.
So for a given gravitational field, heavier, colder molecules
are more easily retained than lighter, hotter molecules.

Given atmospheric temperature, and given atmospheric molecular
mass, the necessary escape velocity is easily determined. Then
a planetary mass can be calculated to supply that field strength.
This is complicated somewhat by density considerations. The G
field gradient is different for a large diameter low density
world than for a smaller denser world.

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: 23 Mar 93 03:15:16 GMT
From: Jim Baker <[e-mail]>
Subject: gravity
Newsgroups: sci.space

Acknowledging the fact that the earth has enough gravity
to hold an atmosphere in place, and the moon (with about 1/6
of earth's gravity) does not, how much gravitiy does it take
to hold an atmosphere?  This is realizing it depends on the
type of atmosphere, but I am looking for a general answer.

Jim Baker <[e-mail]>

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

Date: 23 Mar 93 05:55:02 GMT
From: George Rachor <[e-mail]>
Subject: Hello Goldstone!
Newsgroups: sci.space

Well... As long as we are into Long shots....

Anybody remember Gentleman named Dave Teter who worked at Goldstone in Fire
suppression a few years back?  I'm trying to reach his son Cameron.

Thanks,

George Rachor Jr.
Aloha, OR

--
George Rachor Jr.    Aloha, OR

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

Date: 24 Mar 93 02:09:48 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Looting in Baikonur & Ukrainian Space Program
Newsgroups: sci.space,talk.politics.space

[e-mail] (Frank Crary) writes:

>In article <[e-mail]> [e-mail] (Brian Yamauchi) writes:
>>Does anyone have more details, either about the looting at Baikonur,
>>the seriousness of the "crippling" of the "launch pad", or about the
>>extent of the Ukrainian space program?

>The Ukrainian program can't be too extensive: The only launch complex
>they have access to is Kapustin Yar. While it is quite equitorial
>for a ex-Soviet site, it is currently only capable of launching
>sounding rockets and very small orbital launchers like the SL-8
>(1.25 tonnes to Low Earth Orbit.)

>                                                Frank Crary
>                                                CU Boulder

In the past, Kapustin Yar did see more use than that... I don't
think un-mothballing the pads would be that much of a problem,
especially considering that a lot of the important stuff was probably
rotated to the horizontal and wheeled into hangers, as the Soviets
were wont to do...
--
Phil Fraering         |"...drag them, kicking and screaming,

[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: Tue, 23 Mar 1993 22:03:28 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Lunar ice transport
Newsgroups: sci.space

In article <stephens.732823101@ngis> [e-mail] (Dave Stephenson) writes:
>Since everyone is now talking about pipelines, how about electrolysing
>the ice at the pole, after all the Sunlight is continuous up there, and
>then building two pipelines one for the OX the other for the H2 and
>down at lunar base the gases supply fuel cells to produce water and
>provide electrical power during the lunar night. During the lunar
>day the H2 and O2 supplies would come in very useful for fuel and LSS,
>and I guess a good proportion of any lunar ice if found will end up
>being electrolysed anyway.

This may, or may not, be the best way to go, but it wasn't allowed
as part of the original problem set. If compressed gas pipelines are
used, much more power is required to move the product gases than is
required to move the water, especially if the water can be self-pumped
to a large extent by solar heating to steam in the pipe itself.

To approach this systematically, we'd need to know the volume of
material expected to be moved, the rate at which it is required to
be moved, and the amount of time the ice mines would remain in operation.
It would also be useful to know why we're bothering with an equatorial
base at all instead of locating the base where the ice, and access to
perpetual sunshine, are. If we are going to refine in situ, it may make
sense to simply use the material as rocket fuel *from the site of production*.
We might come out best simply flying tanker loads of the stuff to wherever
it's needed on Luna.

Pipelines can be extremely efficient, but only if the requirement is to
move enough bulk product from point A to point B for a long enough time
interval to amortize the pipeline construction expense.

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: Tue, 23 Mar 1993 22:12:48 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Predicting gravity wave quantization & Cosmic Noise
Newsgroups: sci.space,sci.astro,sci.physics,alt.sci.planetary

In article <[e-mail]> [e-mail] (Cameron Randale Bass) writes:
>     So you increase the wavelength and decrease the frequency.
>     It would also seem to me that in such a situations clocks run slow
>     'within' the gravitational disturbance.  The two disturbances
>     (gravitational and electromagnetic) fly back to the detector,
>     and the gravitational disturbance slows the 'clocks' at
>     the receiver to effectively increase the frequency
>     and cancel the effect.

If we assume that the gravitational wave is a classical wavefront,
and we assume it travels at lightspeed, then your objection only
occurs when the Earth, satellite, and source of gravity waves are
all lined up. If the gravitational disturbance is arriving from
some angle off that line, the EM wave and the gravity wave will
only be coincident at one point along the line of sight.

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, 24 Mar 1993 00:01:03 GMT
From: Henry Spencer <[e-mail]>
Subject: Rocket clones: reduce risk of introducing new tech
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Szabo) writes:
>Thus the heart of my rocket clone proposal: when introducing new
>rocket technology, use it to launch current payloads.  When
>introducing new classes of payloads, use existing rocket technology.

This makes considerable sense for incremental improvements to existing
technology, especially if you insist that each step show a profit.  It
won't break us out of the nasty trap we're in, however, in which costly
launches drive costly payloads which drive costly launches.  Massive
cost reductions are of limited interest to the current major payload
suppliers, who consider current prices tolerable (unsurprisingly, since
the payloads cost much more than the launches already).  Oh, they like
the idea of reducing costs, but they don't care that much about it,
as witness the fact that Proton and Long March launch capacity is idle
while the more expensive Ariane has a long backlog.

As witness Pegasus, it *is* possible to create a new payload class with
a new launcher.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 24 Mar 93 06:27:10 GMT
From: Brian Yamauchi <[e-mail]>
Subject: SSF Redesign....
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Andy Cohen) writes:

>*** Forwarding note from HBAKER  --TMISMAIL 03/22/93 14:37 ***
>From: HUGH BAKER

>A note to try to keep you apprised of the happenings on redesign/cost
>reduction effort by the Program.

First of all, thanks for posting this update -- it's nice to be able
to get the inside information...

>The Goldin letter groundrules changed that had the most effect on the
>decisions here were the ones having to do with making the Station
>man-tended instead of permanently manned, slipping the man-tended date
>requirement about a year, and reducing the design-to life of the Station
>from 30 to 10 years.

Given that the station is going to be man-tended instead of
permanently manned, what is its mission?

    1) Microgravity materials science only
or    2) Microgravity materials science + life sciences

If (2), then are we talking about animal experiments only, or human
experiments as well (and if the latter, what is the maximum duration
stay that will be possible)?

>The result of the changes leave us with a Station with no port truss (may
>be scarred for growth option),

Does this mean there will be no truss at all in the baseline design?

>no HAB module, two IEA/PVAs for 37 KVA of
>total power (15 KVA to users), no ACRV, and one two-loop TCS radiator.

Is there going to be an American experiment module, or is the station
going to rely completely on the European/Japanese modules?

>The Internationals stated this
>morning that they will agree to participate in the Shea Team only is a list
>of conditions is met, among them that one of the three concepts to be
>considered is a SSF derivative, but not necessarily the one the Program has
>developed.

What other non-SSF-derived concepts are being considered?  Are
stations based on external tanks or inflatable structures being
considered as options?
--
_______________________________________________________________________________

Brian Yamauchi            Case Western Reserve University
[e-mail]    Department of Computer Engineering and Science
_______________________________________________________________________________

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

Date: 24 Mar 93 03:13:49 GMT
From: Henry Spencer <[e-mail]>
Subject: SSTO: A Spaceship for the rest of us
Newsgroups: sci.space

In article <1oo99v$[e-mail]> Dave Akin <[e-mail]> writes:
>... Why is it
>that an operational version of DC-X won't need
>refurbishment? ...  I have yet to hear any cogent explanation
>of what makes this vehicle so much robust than any other
>launch vehicle ever developed.

Just how many launch vehicles are you comparing it to?  There is only
one other data point -- the shuttle -- and although that data point is
not a favorable one, a single data point does not a graph make.

Why *should* it need major refurbishment?  How many aircraft do you
know of -- even high-performance ones that fly demanding missions --
that do?  There's very little in DC-Y, or in the shuttle, that sees
stresses greater than those of fighter aircraft.  About the only
issue is the engines... and long-life low-maintenance rocket engines
are far from unknown; the shuttle engines are the worst case, not
the typical one.  The RL-10, for example, is rated for over an hour
of firing, with up to ten restarts, without maintenance.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: 24 Mar 1993 00:17:03 GMT
From: Dave Akin <[e-mail]>
Subject: SSTO: A Spaceship for the rest of us
Newsgroups: sci.space

In article <[e-mail]> Allen W. Sherzer, [e-mail]
writes:
>In article <[e-mail]> [e-mail]
(Andy Cohen) writes:
>
>>My point is that there is no refurbishing....just refueling.... [for DC]
>
>Well that's not strictly true (you would need to repeal the second law
>of thermodynamics for that). It's just that DC souldn't need refurbishing
>after every flight (or at least not much).
Well, first of all, I was really talking more about the
downstream operational versions of DC-X, not the X-
vehicle itself (and by the way, I heard a rumor it's being
designated X-32???)

But I'm willing to learn, so please enlighten me. Why is it
that an operational version of DC-X won't need
refurbishment? It has multiple rocket engines with
turbopumps, it goes from launch through Mach 25 and back
through a full orbital entry, it has to do a powered pull-up
maneuver and land vertically, why is this vehicle magic
enough that it doesn't need refurbishment and/or checkout?
I understand about designing for abort or mission
continuation following a failure (like a turbopump failure)
and I think that's a great feature that will make the system
more resiliant, but I have yet to hear any cogent explanation
of what makes this vehicle so much robust than any other
launch vehicle ever developed.

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

Date: Tue, 23 Mar 1993 23:38:05 GMT
From: Henry Spencer <[e-mail]>
Subject: waste management...
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (IGOR) writes:
>Are those wastes processed ? ...

Solid wastes are stored on board for disposal on the ground.  Urine is
sometimes sampled for biomedical investigation, but most of it is dumped
overboard periodically.

It is not practical to recycle human wastes within the mass (etc.)
constraints of the shuttle.  The space-station people were looking at
water recycling, including urine recycling, although that may have
been canned as part of one of the cutbacks.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

End of Space Digest Volume 16 : Issue 360
------------------------------