Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_2/v16no222.txt

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Date: Wed, 24 Feb 93 05:32:27
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #222
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 24 Feb 93       Volume 16 : Issue 222

Today's Topics:
                       >>>>>Question about FRED
                      A response from Anonymous
             EVA time (was Re: Nobody cares about Fred? )
                  Getting people into Space Program!
                               ICE Ship
                        McElwaine disciplined!
                McElwaine disciplined! (somewhat long)
                           PEGASUS QUESTION
       Reliable Source says Freedom Dead, Freedom II to be dev
    Reliable Source says Freedom Dead, Freedom II to be developed
        Wouldn't an earth to moon shuttle be better than fred?

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

Date: Sat, 20 Feb 1993 23:38:31 GMT
From: Henry Spencer <[e-mail]>
Subject: >>>>>Question about FRED
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mark Smilor) writes:
>    2) My second question is could a private US corporation do a similar
>space station (ie. size, mass, functions, power level, etc) for a significantly
>smaller price, like $4 billion ?

Space Commerce Corp., a few years ago, estimated $500 million, although I
think that was for a somewhat more modest station.  That assumed launch by
the lowest bidder (that is, on Proton) and hardware built by construction
companies (who build things heavier but much much cheaper than aerospace
companies).

Double it for greater capabilities, double it again for use of US launchers
(real competitive bidding would keep costs down, but not to Proton levels),
and you've still got a factor of two in hand for overruns.  Sounds feasible.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: 23 Feb 1993 05:26:12 GMT
From: Shari L Brooks <[e-mail]>
Subject: A response from Anonymous
Newsgroups: news.admin.policy,alt.privacy,comp.org.eff.talk,sci.space,sci.astro

In article <[e-mail]> [e-mail] (Michael Parks Swaim)
writes:

>  Call me stupid, but I think that a plainly visible notice that says
>"Don't peek" should be enough. (No, I don't think that the SRI notice was
>plainly visible.)

Just like a "no Trespassing" sign on someone's property edge is enough?
Get real.  These signs don't work unless accompanied by a threat of violence
or prosecution and/or barbed wire, and likewise a "don't peek" notice
won't work unless it is accompanied by the lack of perms to look in
forbidden directories at forbidden files.


--
If you blow fire against the wind, take care to not get the smoke in your eyes.
      Big & Growly Dragon-monster        |        [e-mail]
   --------> shari brooks <--------      |    [e-mail]
                      The above opinions are solely my own.

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

Date: 20 Feb 93 19:52:59 GMT
From: CLAUDIO OLIVEIRA EGALON <[e-mail]>
Subject: EVA time (was Re: Nobody cares about Fred? )
Newsgroups: sci.space

> And maybe I'm wrong, I don't have the figures handy, but didn't the
>   U.S. log more EVA time in 1992 than did Russia?

I remember that sometime ago I read that Americans had more EVA time than
Russians (Soviets??). Is it still true???

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

Date: Tue, 23 Feb 1993 05:43:28 GMT
From: Dave Michelson <[e-mail]>
Subject: Getting people into Space Program!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>   There were 99 X-15 missions, far fewer that qualified as spaceflight.

There were *199* X-15 missions....

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

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

Date: Mon, 22 Feb 1993 22:34:43 GMT
From: Nick Szabo <[e-mail]>
Subject: ICE Ship
Newsgroups: sci.space

[e-mail] (Gary Coffman) writes:

>I don't think this could be called an ice spaceship. That has conotations
>of a vessel carrying a cargo, not of the vessel *being* the cargo.

It can work either way.  The cargo can be more ice, or organics, or
anything else found on the comet.  The ice rocket can also transfer
to an asteroid and pick up cargo (eg metal regolith), return astronauts
or samples from Mars orbit to Earth orbit, etc.

>What you're doing is changing the orbit of an existing ice planetoid
>using native reaction materials. If the materials are sufficiently pure,
>it would be reasonable to use a steam rocket. If they aren't, a mass
>driver would be better...

We can get over an order of magnitude more power per unit mass with
a thermal system (microgravity mirrors and heat exchangers) than with
an electric system (solar cells, magnets and armatures).  The processing
equipment, which should operate for about a year and produce 10,000
times its own mass in ice, purifies the water via centrifuge, or alternately
distills out ammonia or methane (which are better thermal propellants
than water, chemically and Isp-wise).  It deposits ice to form a dynamically
balanced cylinder.  So, the ice rocket doesn't much resemble the original
comet or asteroid ice deposit.  Indeed, we can mass produce ice rockets
the size of a Delta rocket or redwood tree trunk, small enough be safely
gravity assisted at Earth.

>If orbital transfer time is long, as would be expected in the general
>case, you might be able to do processing in flight and wind up delivering
>*only* processed material at destination. This would likely be the most
>efficient case.

This is a possibility, but in most scenarios I think it is more economical
to take the 10-40% interest cost hit and do the end-user processing in
high Earth orbit instead of hauling more equipment all the way out to the
comet.  For the first mission, this has the advantage that we don't
have to launch most of the equipment until the ice is already in
earth orbit (if the mission fails, we can cut our losses).  As ice
propellant becomes cheap from bootstrapping, it becomes much
cheaper to transfer equipment around the solar system than to launch
it in the first place, so these economies may change as the system
matures.


--
Nick Szabo                     [e-mail]

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

Date: 23 Feb 93 03:44:58 GMT
From: Sea Wasp <[e-mail]>
Subject: McElwaine disciplined!
Newsgroups: sci.skeptic,sci.space,sci.astro,sci.space.shuttle

In article <[e-mail]> [e-mail] () writes:
>It always worries me when someone is stomped on because of what he says,
>even if what he says is unadulturated gibberish.  Are we so thin-skinned
>that we can't just ignore stuff we don't want to see?

    He's  not being stomped on because of WHAT he says (PARDON my
MCELWAININAN descent into CAPS), but because he doesn't have the basic
decency to post his stuff, BS or not, ONCE, or maybe TWICE, but instead
chooses to automatically post it  all over the freaking place, and
he also never responds to anything sent to him (I've sent him almost
a dozen letters). In  short, he's being stomped on because  he's a
deliberate nuisance.

    Remember: "Posting this will cost hundreds if not thousands of
dollars". Considering  that I've seen this loon on the nets for over a
year and he posts at least three times a week,

    3*52 [automated posts take no holidays] = 156

    156 * 200 (most conservative interpretation of "hundreds if not
thousands) = 31,200

    Since his posts are very  long, it might be more proper to assume
a figure of 1,000 instead of 200 -- in either case, he's eating up an awful
lot of other  people's money for no purpose.


                                 Sea Wasp
                                   /^\
                                   ;;;

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

Date: 20 Feb 93 19:53:34 GMT
From: "Russell J. Pagenkopf" <[e-mail]>
Subject: McElwaine disciplined! (somewhat long)
Newsgroups: sci.skeptic,sci.space,sci.astro,sci.space.shuttle

In article <[e-mail]> [e-mail] () writes:
>It always worries me when someone is stomped on because of what he says,
>even if what he says is unadulturated gibberish.  Are we so thin-skinned
>that we can't just ignore stuff we don't want to see?

* SOAPBOX ON *

I must agree with you Andrew.  Just because *you* (newsgroups in
general) don't agree with what someone has to say doesn't mean you have the
right to CENSOR him/her.  Yes, I agree that sometimes some of the posts can be
downright outrageous/annoying, and yes, you might think that this one is
too, but just because you don't agree with what I or McElwaine have to say
doesn't give you the right to tell me that I can't post this.  The
newsgroups are really just a reflection of the world around us, and in
some ways they are a little more anarchic, but just like the real world
you DO have the option to turn away.  You *can* press C or N or K if you
find the post offensive or tiresome.

Should McElwaine have his Internet privileges taken away?  I don't believe
so.  You may disagree with what he has to say, you may be able to prove
him absolutely wrong, you may feel offended by what he posts, but he has
the right to say what he wants just like you.  I grant you that there are
limits, but those deal with appropriateness of the newsgroups you post to
and the number of groups you post to.

These newsgroups are bastions of free speech (free typing ;-) ) and I
treasure that immensely.  I do not subscribe to all of the newsgroups,
simply because there is not enough time in a day to read it all, but if
there was I would.  I learn more everyday from reading these newsgroups
than if I were to attempt to find the information myself.  They help me form
opinions about issues and I believe they help to make me a better, and more
educated person, and THAT is probably the best praise of all for the
newsgroups.  Yes, even posts like McElwaines' are a part of this.

One final note, and this is personal, I felt that some of the replies to
what was posted were both rude and obnoxiuos.  IMHO, if you're want to
flame someone like that e-mail them instead of posting to the net in
general, or post information that *shows* us why he is wrong, flaming
turns almost everyone off (unless you read *.flame ;-) ).

* SOAPBOX OFF *

I apologize for the length for the length of this post, but I felt I
couldn't stay silent.  If you disagree with what I have to say, that's ok
you've got your opinions I've got mine, and if you'd like to *discuss* this
further lets do it through e-mail.  If you vehemently disagree and want to
send flames that's ok too, I'll read them and throw them away.  If you've read
this far, thank-you for listening.

--
Russ Pagenkopf                    "Heading, Sir?"
[e-mail]                 "Out there. Thataway."
[e-mail]         "A most logical choice, Captain."

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

Date: Sat, 20 Feb 1993 23:32:21 GMT
From: Henry Spencer <[e-mail]>
Subject: PEGASUS QUESTION
Newsgroups: sci.space

Organization: U of Toronto Zoology
Lines: 14
Sender: [e-mail]
Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]> [e-mail] (Bob McGwier) writes:
>It is MUCH easier to maintain the stability of a vehicle that is already
>moving and is effectively gliding that it is to stabilize a rocket in
>vertical takeoff from a standing start.  This is intuitively obvious to
>me at any rate.

Only if you're using aerodynamic stabilization (which presumes an
aerodynamically stable vehicle -- not all rockets are).  Note that two
out of three Pegasus stages are essentially non-aerodynamic.  If your
stabilization is being done by something like engine gimballing, initial
velocity or lack thereof is entirely irrelevant.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

Date: 20 Feb 93 23:03:23 GMT
From: "Phil G. Fraering" <[e-mail]>
Subject: Reliable Source says Freedom Dead, Freedom II to be dev
Newsgroups: sci.space

[e-mail] (Brian Stuart Thorn) writes:

>    Oh well, I guess our youth can look forward to building nice
>    highways in the future, not much else.

As someone in the _only_ industry (the energy industry) being targeted
with a new tax increace (as if it were immoral, or as if we were doing
well during the Reagan/Bush era instead of slowly going out of
business), I'd like to say that the highways will be nice, but that's
besides the point if all you can drive on them are nice little golf
carts....

>-------------------------------------------------------------------------
>Brian S. Thorn                                    "If ignorance is bliss,
>[e-mail]                               this must be heaven."
>                                                -Diane Chambers, "Cheers"
>-------------------------------------------------------------------------

One good thing for all the ignerant people, who can at least drive:

At least they'll all be able to register at the driver's registration
place, or by mail if your car burned oil, natural gas, or coal.

Of course, given the stuff I've heard out of Nevada, registration
(quote unquote) will be simply another way of enthroning the
democrats permanently...
--
Phil Fraering         |"...drag them, kicking and screaming,
[e-mail]|into the Century of the Fruitbat." - Terry Pratchett,
                       _Reaper Man_

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

Date: Sat, 20 Feb 1993 18:54:53 GMT
From: Frank Crary <[e-mail]>
Subject: Reliable Source says Freedom Dead, Freedom II to be developed
Newsgroups: sci.space

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

>SO if we re-do SSF , how should we do it.

>Are trusses inherently more costly and problematic?
>certainly it allows larger growth.

They also permit more effecient use of solar panels and radiators.
However, it isn't clear how necessary this hightened efficiency is
to the station as a whole. The truss certainly increases cost and
causes stability/dynamic problems. Worse, it substantially increases
construction and maintaince cost/effort/time.

>Should we look at something made from ETclusters along
>with Pre-built modules and inflatable zones?

We should certainly _look_ at such a design. I'm not sure if it's the
best choice, but it might be. (Skylab was essentially a modified
fuel tank, so the idea has been tried sucessfully.)

>Should we look at higher altitudes and and steeper inclination orbits?

Unless you have some unusual purpose for the station (or want to
use Russian/Kazak launch facilities, I'd say no. A higher inclination
would substantially increase launch costs, so it would be a bad idea
without some substantial benefits to compensate. As for a higher
orbit, while it would decrease station keeping fuel costs, it also
makes access to the station more difficult. Remember, _something_
has to launch the station, and something will have to regularly
transport supplies there and rotate crews. A station in a higher
orbit would be far less accessable to the space shuttle. Perhaps
the best solution would be that used by the Soviets (and still
used by the Russians): Allow the station's orbit to gradually
decay, using the station keeping rockets to re-boots the station
only once every few months (I.e. so that the station's altitude
varies over a substantial range.) Resupply launches and crew
rotations can be times to occur when the station is at it's
minimum altitude, and therefore most accessable. But since the
station does not remain at this accessable altitude, it experiences
(on average) far less atmospheric drag, and requires far less
station keeping fuel.

But the real vital (and politically impossible) part of designing
a new station isn't any particular technical detail: The purpose
of the station must be clearly defined from the start, and the
available funding must be known and remain unchanged. That's
really the key to all the technical choices: The advantages
and disadvantages of any particular design depend on the
intended use of the station, and the moeny available (spending
alot of money to make a construction shack/on-orbit repair
facility completely vibration free would be a waste, but it
would be vital for a micro-gravity materials lab.) If there is/was
any single problem with Freedom that stands out, it was the
lack of a clear purpose. The design tried to do everything, and
satisfy every purpose. As a result, it was very expensive and
complex. Later (too late), the design requirments were narrowed
to save money, but the basic design was left unchanged. The result
is a design that isn't optimized for it's purpose...

                                                Frank Crary
                                                CU Boulder

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

Date: Sat, 20 Feb 1993 21:43:05 GMT
From: Joe Cain <[e-mail]>
Subject: Wouldn't an earth to moon shuttle be better than fred?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>In article <[e-mail]>, [e-mail] (Robert Ivan) writes:
>|>
>|>   It seems to me that having a earth to moon shuttle would be a far more
>|> suitable use of resources. Something that could take a few people and cargo
>|> out to the moon and back to earth orbit.  Okay, I know that somebody will
>|> argue that a space station is needed in between.

    NASA an most others agree that a space station is virtually
useless as a staging point between the Earth and Moon or Mars. I
brought this point up with one of the people in Goldin's entourage in
Tampa in December. He told me that getting them in the proper position
on a return is almost impossible. They thus have no plans to use a
space station as an intermediate stop to or from any planet.

Joseph Cain        [e-mail]
[e-mail]        scri::cain
[phone]        FAX [phone] or -0098

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

End of Space Digest Volume 16 : Issue 222
------------------------------