Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V11_0/V11_040.ZIP/V11_040

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Subject: SPACE Digest V11 #40

SPACE Digest                                      Volume 11 : Issue 40

Today's Topics:
              Re:  SPACE Digest V11 #39
            Subscription addition/removal
    Energy (was Re: Spacecraft drives and fuel efficiency)
        Fun Space Fact #1:  Launcher Development Costs
            Re: metric vs. imperial units
               Re: Space Station Costs
            Re: metric vs. imperial units
            Re: Kepler fudged the Numbers?
        Soyuz TM-9 docks with Soviet Mir Space Station
               Re: Recreation in Space
            Re: Kepler fudged the Numbers?
              SPACE Digest Subscription
              ESA Publications Division
----------------------------------------------------------------------

Date:     Tue, 13 Feb 90 8:20:43 EST
From: Jerry <[e-mail]>
Subject:  Re:  SPACE Digest V11 #39

Please remove me from your mailing list.

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

Date: Tue, 13 Feb 90 16:15:10 -0500 (EST)
From: Kevin William Ryan <[e-mail]>
To: [e-mail], Space <[e-mail]>
Subject: Subscription addition/removal

   Send to space-request, not to space.  Most of the digests are prepared
by automated digest software, and the moderator might miss such requests.
The [e-mail] address goes directly to the moderator.

                                                 kwr

   "Jest so ya know..."

P.S.  Again - all requests for addition/deletion on the space digest
      mailing list should be directed to [e-mail]
      in order to reach the moderator.

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

Date: 13 Feb 90 19:38:50 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Energy (was Re: Spacecraft drives and fuel efficiency)

A couple of minor corrections:

4e26 watts is enough power to launch a 30 million ton spacecraft
to .5 c once per second, not 15 million tons.  Also, the kinetic
energy of a 10 km asteroid going at 20 km/s is about 80 teratons,
not 20.

Exercise for the day: if you wanted to blast the atmosphere off
Venus in preparation for terraforming, how much antimatter would you
need?  If you use fusion bombs, how much deuterium?

    Paul F. Dietz
    [e-mail]

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

Date: Tue, 13 Feb 90 14:24:02 PST
From: mordor!lll-tis!ames!ucsd!pnet01.cts.com![e-mail] (Jim Bowery)
To: crash![e-mail]
Subject: Fun Space Fact #1:  Launcher Development Costs


The Shuttle cost around $(1990)30 Billion to develop and it
doesn't work very well.

The American Rocket Company (AMROC) cost about $(1990)30 Million
to start up and it developed a launcher that is likely to work
very well.

That's a factor of ONE THOUSAND less.

I wonder what would happen if you just passed out one thousand
chunks of money at $30 million a crack to anyone who looked
vaguely like they had an idea about how to build a better launcher
(and, of course, kept them away from metropolitan areas :-).
---
Typical RESEARCH grant:
$
Typical DEVELOPMENT contract:
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

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

Date: 13 Feb 90 16:56:29 GMT
From: snorkelwacker!usc!jarthur![e-mail]  (John H. Kim)
Subject: Re: metric vs. imperial units

In article <[e-mail]> [e-mail] (Greg Wilkins) writes:
>
>The whole point is that metric has many big points in its favour:
>
> - To some extent, when designing physical systems, recurring decimal
>   places can be avoided, hence round off errors can be reduced.

Gee.  Why don't we just switch to Gaussian units then? :-)
--
John H. Kim                 | (This space to be filled when I
[e-mail] | think of something very clever
uunet!muddcs!jarthur!jokim  | to use as a disclaimer)

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

Date: 13 Feb 90 16:48:05 GMT
From: zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Space Station Costs

In article <[e-mail]> [e-mail] (Free speech is a sound investment) writes:
>[Following along on the thread about the cost of LLNL's space station
>    (and lunar base)]
>
>What about LLNL's idea?  Is it plausible?  Cost effective?

The jury is still out on it.  NASA claims the technology is decidedly
optimistic; LLNL counterclaims that virtually all the technology is from
NASA's own past efforts.  (The figures on inflatable structures come from
the folks who make NASA spacesuits, for example.)  The cost figures are
probably over-optimistic -- cost estimates at this stage always are -- but
it does seem like it would be worth a try.  It's not likely that it will
get a chance unless it is rammed down NASA's throat by higher management.
Just going ahead and *doing the job*, forgetting all the crap about new
technology and advanced robotics and 57 unmanned preliminary missions,
may sound attractive to space enthusiasts, but the reaction from the NASA
facilities and contractors -- who together have a lot of political clout --
will be basically "sounds like less money for us -- we're against it".

>Didn't the VP meet with those folks awhile back?  What was the outcome?

So far the only real outcome has been some ringing speeches about the
need to give more attention to outside ideas, with veiled hints that NASA
may not have the final say quite as often as it would like.  Nothing very
concrete yet.

>Should we develop the idea in paralell (sp?) and let the best proposal win??

That would be a great idea except that Congress doesn't especially like
funding parallel efforts and all the Space Authorities (i.e. NASA) will
be against it on the off-chance that LLNL might win.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: 13 Feb 90 08:51:15 GMT
From: eru!luth!sunic!mcsun!ukc!acorn!ixi![e-mail]  (Clive Feather)
Subject: Re: metric vs. imperial units

In article <[e-mail]> [e-mail] (Per Danielsson) writes:
>I'm quite sure that aviation in Australia uses feet for altitudes and
>nautical miles for distances, just as the rest of civilian aviation in
>the world (with a few exceptions: the USSR being the one really
>important one, but Russian pilots have to use feet and nm when they
>fly outside the USSR ...).

Equally, British Airways pilots have to use metres when flying trans-Soviet
sectors (London-Hong Kong, London-Moscow, Moscow-Tokyo, etc.). The
flight-engineer has a little card with three columns on it:

      m              feet
    305     1000     3281
    610     2000     6562

etc.
--
Clive D.W. Feather  | IXI Limited           | [phone] (v)
[e-mail]     | 62-74 Burleigh Street | [phone] (fax)
...!uunet!ixi!clive | Cambridge  U.K.       |-----------------------------
                    | CB1  1OJ              | Silly quote being thought up

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

Date: 13 Feb 90 16:47:35 GMT
From: brutus.cs.uiuc.edu!uakari.primate.wisc.edu!uflorida!mephisto!prism![e-mail]  (Lancelot du Lac)
Subject: Re: Kepler fudged the Numbers?

In article <[e-mail]> [e-mail] (mike.siemon) writes:
>In article <[e-mail]>,
>[e-mail] (Ingo Cyliax) writes:
>
>>I always thought he made several mistakes in his math, some of which cancelled
>>each other out.

From what I heard, no. What he did was make several mathematical errors that
caused him to mistakenly reject the correct answer, then went back quite a
while later and re-figured. (More on this particular point in a moment)

>it turns out the every point on the orbit so given is in fact
>given *exactly* by Kepler's ellipse formulae

This (by my information) is due to the fashion in which he solved the
problem. Trial and error. My understanding, is that he would Compute a
possible orbit, calculate what the positions Mars would be in for the
time points he had, and then check his computations against the data
gathered by Brache. He would then adjust the orbit to minimize error,
recalculate and recompare. Much like the Newtonian approximation. And,
like the approximation, it is possible given enough time to get an
arbitrarily accurate solution. One would, however, stop when one reached
the error values of the observational data. Kepler, being somewhat of a
perfectionist, would naturally ascribe the minimum possible error to Tycho
Brache's data, so that he could get the maximum possible accuracy.

>Having seen only the journalistic account, I have no real opinion here; I
>would guess that the translator noticed a remarkable *lack* of observational
>error -- and presumably Kepler was too troubled by residual differences from
>his ellipses that he couldn't account for, so he decided not to bother his
>readers with this problem.

A possibility, but remember, that Kepler's three Laws were based on Tycho
Brache's data and his own ellipses. It is all but impossible (save by sheerest
coincidence) to accurately describe formulae and general cases and formulate
laws which yeild accurate predictions (which Kepler's did) when all of these
are based on data that one has fudged.

--
David Kidd - Georgia Tech                | "Oh, I feel like such a pompus
uucp:      ...!{decvax,hplabs,ncar,       |  twit!"
     purdue,rutgers}!gatech!prism!ccastdk|
Internet: [e-mail]       | "It's what you do best, my love."

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

Date: Tue, 13 Feb 90 18:35:08 EST
From: Glenn Chapman <[e-mail]>
To: <@cunyvm.cuny.edu:[e-mail]>,
        [e-mail],
        [e-mail], [e-mail],
        [e-mail], [e-mail]
Subject: Soyuz TM-9 docks with Soviet Mir Space Station

     The Russian's Soyuz TM-9 capsule successfully docked with their Mir
space station this morning, Feb. 13th, some two days after its Feb. 11th
launch. On board were Anatoly Solovyov and Alexander Balandin, who will be
staying up there for a six month mission. They were greeted by Alexander
Viktorenko and Alexander Serebrov who have now been in orbit for 161 days.
Television pictures of the docking were carried on Vermya (the Soviet
nightly news) indicating the docking was to the Kvant 1 module at the rear
of the station, as expected.  When the hatch was opened the new cosmonauts
appeared to enter a rather spacious section of Mir/Kvant1/2, with one of
the long duration crew holding what appeared to be a bouquet of flowers
(the traditional greetings for a traveller is bread, salt and flowers).
All the cosmonauts floated around a table, though their voices were not
heard on camera.  Viktorenko and Serebrov appeared to be in good shape.
They will be coming down in about one week according to the announcement,
in keeping with the Feb. 20th date mentioned in my last posting, not the
original Feb. 24th plans.  It will also mean that both cosmonauts will be
about 5 to 7 days short of one half year accumulative time in space when
their previous missions are added in. (Radio Moscow & Moscow TV, Feb. 13)
     Some interesting comparisons were released between the NASA's Manned
Maneuvering Unit and the Soviet's space bicycle, also called SPK, or
Icarus, that Viktorenko an Serebrov tested twice earlier this month.  Its
Russian system's mass is 200 Kg (440 lbs.) about 25% heavier than the 148
Kg (325 lbs.) MMU.  However, its top velocity is 30 meters per second or
108 Kph (98 ft/sec or 66 mph), more than twice that of the 14 m/sec or 49
Kph (45 ft/sec or 31 mph) of the US MMU.  This suggests that the compressed
nitrogen gas load is about 31 Kg (68 lbs), compared to 11.8 Kg (26 lbs) on
the MMU. This calculation assumes the same mass of man and suit, and same
gas pressure, obviously rather rough values.  All things being equal that
means the Soviet system should be able to operate at about 2.2 times the
maximum safe distance of the MMU 's 137 meters (450 ft) or say 300 meters
(990 ft).  The fact that this is a nice round number metric number suggests
that it may be the design distance. (Space News Feb. 5)
     One point to note is that the leaving date for the Soyuz TM-8 crew
will be the fourth anniversary of the orbiting of Mir.  On May 29th this
new crew will see Mir become the longest lasting operational space station,
exceeding Salyut 7's 4.2 years.  At that point Mir will be in every
respect the earth's most successful space station.

                                                  Glenn Chapman
                                                  MIT Lincoln Lab

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

Date: 13 Feb 90 23:35:12 GMT
From: shelby!portia![e-mail]  (Raul Izahi Lopez Hernandez)
Subject: Re: Recreation in Space

In article <[e-mail]> [e-mail] (James Turner) writes:
>[e-mail] (Henry Spencer) writes:
>
>>In article <[e-mail]> [e-mail] (bill davidsen) writes:
>>>  Let me give you a hint... if I were going to be on a multiyear
>>>mission, I would want female astronauts.
>
>>I dimly recall seeing an account from one of the Skylab astronauts which
>>commented on this. :-)  He said that NASA told them they had a mass
>>budget of 60-odd kg for recreation, and "after management rejected our
>>unanimous first suggestion", this was used on games, tapes, etc.

>Actually, I suspect that if the additional 60kg had represented the entire
>weight of a Recreational Coupling Mate/Demate Facility (RCMDF), they would
>have given the OK.  Unfortunately, you have to factor in N times the RCMDF's
>weight in O2, food, water, and other life-support trivia.

   Sorry guys, I don't like to joke if there is one.
   I'm aware that this is a mostly male community but I don't agree with
even the smallest hint of sexism here or anywhere else.
   I was talking with some friends about the origin of thiking and if
it happened to one individual long ago in a primitive community, I want
to believe it happened to a woman who had a dominant genetics and then
"smart" people were born afterwards.
   I'm really happy to see that everyday more women are involved in
space science both as astronauts and as scientists.
   So everybody keep up the good work.

                        RAUL IZAHI
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Raul Izahi Lopez Hernandez    [e-mail]
Graduate Student, EE Dept.    "Nun, ich war und ich bin noch Student,
Stanford University            denn ein Student bleibt ewig Student!" -DG

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

Date: 13 Feb 90 04:27:31 GMT
From: att!cbnewsm![e-mail]  (mike.siemon)
Subject: Re: Kepler fudged the Numbers?

In article <[e-mail]>,
[e-mail] (Ingo Cyliax) writes:

> I always thought he made several mistakes in his math, some of which cancelled
> each other out.

That's the old Koestler (_Sleepwalkers_) line.  The new report (bruited in
the NY Times Tuesday science section a few weeks ago, for example) is from
the person who is undertaking a current scholarly translation of his work.
The translator says that, in attempting to follow out in detail the complex
trigonometric computations that Kepler *says* he did on the basis of Tycho's
data (there is an excellent elementary discussion of this in a Dover book
by Ryabov that I remember from some 30 years ago, without having it on hand
to reference) it turns out the every point on the orbit so given is in fact
given *exactly* by Kepler's ellipse formulae -- i.e., he generated the points
he "knew" were correct and constructued pseudo-observational data to support
that.

Having seen only the journalistic account, I have no real opinion here; I
would guess that the translator noticed a remarkable *lack* of observational
error -- and presumably Kepler was too troubled by residual differences from
his ellipses that he couldn't account for, so he decided not to bother his
readers with this problem.

It all goes to confirm my impression that the only people who actually
*read* scientific reports in detail are graduate students who have to give
seminar papers on them :-)


--
Michael L. Siemon        In so far as people think they can see the
cucard!dasys1!mls        "limits of human understanding", they think
att!sfbat!mls            of course that they can see beyond these.
standard disclaimer                -- Ludwig Wittgenstein

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

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Subject:  SPACE Digest Subscription

I seem to be unable to get off of this list. Any suggestions?
Thanks...Chuck Darney

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

Date: 13 Feb 90 09:02:56 GMT
From: mcsun!hp4nl!phigate!prle!prles2!cstw10![e-mail]  (Harm Munk)
Subject: ESA Publications Division


A few weeks ago someone mentioned the ESA Publications Office as the place to
get a subscription to ESA Journal and ESA Bulletin. However, the address in
the posting was incorrect (outdated ?). Here follows the correct address:

ESA Publications Division
P.O. Box 299
2200 AG  NOORDWIJK
The Netherlands

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End of SPACE Digest V11 #40
*******************