Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_4/V11_448.TXT

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Subject: SPACE Digest V11 #448

SPACE Digest                                     Volume 11 : Issue 448

Today's Topics:
               Re: German MIR astronaut
               Re: Splitting sci.space
               Re: wooden ships
             Reduction of HST CCD images
               Re: Splitting sci.space
Re: DOD/NASA announce National Aero-Space Plane contractor team (Forwarded)
          Re: COMPARISON OF PROBE TECHNOLOGY
       Re: NASA Headline News for 05/18/90 (Forwarded)
             Re: Manned mission to Venus
              Re: NASA Select TV
            Re: terraforming Venus
DOD/NASA announce National Aero-Space Plane contractor team (Forwarded)
               Re: wooden ships
----------------------------------------------------------------------

Date: 24 May 90 05:38:07 GMT
From: usc!samsung!umich!mailrus!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: German MIR astronaut

In article <[e-mail]> [e-mail] writes:
>A german astronaut is scheduled to make a trip to the Soviet Space
>Station, MIR.  I would like to know if the primary and backup
>candidates have been selected yet...

The mission has only just received political approval from both sides.
I doubt that they are actively looking for candidates yet, much less
finished deciding on a pair.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 24 May 90 05:24:40 GMT
From: sdd.hp.com!samsung!cs.utexas.edu!mailrus!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Splitting sci.space

In article <[e-mail]> tneff@bfmny0%UUNET.UU.NET (Tom Neff) writes:
>Looking at the subject lists, I'd say one split that could profitably be
>done is to put the "updates" in their own group, sci.space.announce...
>This could even be moderated (although the mail leg might cost in
>timeliness), and followups consistently directed to sci.space.
>
>If we did this I think we could zorch .shuttle.

Historically, the original purpose of .shuttle was in fact for news updates,
not for specifically shuttle-related discussion.  Sci.space.announce, or
something like that -- awkward name, but it's hard to find a better one
that doesn't invite more general chit-chat -- sounds like a reasonable
idea.

I don't think it is necessary to moderate it.  All that is really required
is to convince the handful of people who regularly post news reports to
put a suitable Followup-To header in their articles.  I can certainly do
that; how do the others feel?
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 24 May 90 18:26:21 GMT
From: spies!zorch![e-mail]  (Phil Gustafson)
Subject: Re: wooden ships

In article <[e-mail]> [e-mail] (Brian or James) writes:

[British are inept explorers.]

Se Roland Huntford's _Scott_and_Amundsen_ for a well-documented exposition
of this.

                    phil

------------------------------------------------------------------------------
    Opinions outside attributed quotations are mine alone.
    Satirical material may not be specifically labeled as such.
------------------------------------------------------------------------------

--
  |  [e-mail]          | Phil Gustafson
  |  (ames|pyramid|vsi1)!zorch!phil      | UNIX/Graphics Consultant
  |                     | 1550 Martin Ave., San Jose CA 95126
  |                     | 408/286-1749

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

Date: 24 May 90 23:25:04 GMT
From: [e-mail]  (Mark Bradford)
Subject: Reduction of HST CCD images

Here's a slightly technical question about Hubble's Wide
Field/Planetary Camera.  (Quick background for people unfamiliar with
the details of CCDs: being silicon chips, they aren't perfect, and so
their systematic flaws must be removed from each image in a process
known as 'reduction.')

I know that they went to great lengths to put the best possible CCD
into HST -- we got one of the rejects for our 24-inch here -- but is
the WF/PC chip so perfect that they don't need to reduce the images?
Or will they spend X amount of time taking sky flats?  Do they plan to
find the average DC bias level on a regular time schedule?

My guess is that they'll use a method similar to that which Tony Tyson
uses for his ultra-deep CCD imaging, and simply use a large number of
slightly-offset images to produce a 'super sky flat,' but I'd like to
hear if anybody knows for sure... thanks!

-- Mark ([e-mail])  <>  To err is human, to moo bovine.

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

Date: 23 May 90 06:11:16 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Splitting sci.space

In article <[e-mail]> [e-mail] (Conor O'Neill) writes:
>While I hate arguments which tend to occur concerning newsgroup splitting,
>yet again I arrive to find hundreds of articles in sci.space.
>We run a seven day expire here, and we have 272 articles spooled,
>in 150 subjects.

I guess the question is whether forty articles a day is too much.  I
don't think it is.  (I see 309 articles on a 10 day expire, by the way,
for only 30/day, but Conor may be adding sci.space.shuttle.)

>Could we perhaps have a discussion on splitting sci.space into a few
>smaller groups.

Looking at the subject lists, I'd say one split that could profitably be
done is to put the "updates" in their own group, sci.space.announce.
This could even be moderated (although the mail leg might cost in
timeliness), and followups consistently directed to sci.space.

If we did this I think we could zorch .shuttle.

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

Date: 24 May 90 23:00:47 GMT
From: sam.cs.cmu.edu![e-mail]  (Vincent Cate)
Subject: Re: DOD/NASA announce National Aero-Space Plane contractor team (Forwarded)

Peter E. Yee:
>     As a presidentially directed joint DOD/NASA program, the
>NASP program objective is to develop technologies for a new
>generation of aero-space vehicles.  This includes single-stage-
>to-orbit space launch vehicles capable of horizontal takeoff and
>landing and long range, hypersonic flight within the atmosphere.

I like the idea building very high speed jets to cut the cost to
orbit.  It should save money to use oxygen from air as long as you can,
thus not having to carry your own as in a rocket.  However, the idea
of a "single-stage-to-orbit" does not make sense to me.  It seems like
you will be paying to take jet engines, wings, jet fuel tanks, and a
large frame, all the way to orbit where they do you no good at all.
It seems like at least 2 stages makes sense.

Are there sound economic reasons for building a single-stage-to-orbit
launcher or was this just a political decision?  Can you use the same
engine as both a jet and a rocket by just adding your own oxygen when
you want it to be a rocket?  Can a "plane" get going so fast on jets that
it is really almost into space? (I find this hard to believe)

Thanks for any info,

   -- Vince

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

Date: 24 May 90 05:33:12 GMT
From: sdd.hp.com!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: COMPARISON OF PROBE TECHNOLOGY

In article <[e-mail]> [e-mail] (Matthew J Rosenwasser) writes:
>Does anyone know how the technology of the Pioneers, Voyager and Vikings
>compare with that of Magellan, Ulyesses, Galileo and the HST?  Can it be
>considered next generation?  ...

There were no sharp generation boundaries, but rather gradual evolution.
Mariner 10 was much more sophisticated than Mariner 2.  And as that example
indicates, you need to be more specific, because some of those programs
spanned a number of years and a number of missions.  Voyager started out
to be Mariners 11 through 13; the first Pioneers pre-dated all other US
planetary missions, but the Pioneer-Venus pair was a relatively recent
mission and the P-V orbiter is still operating.

Actually, there *is* a major generation gap visible, but it's after all
the missions you mention.  Remember that most of the hardware for Magellan,
Ulysses, Galileo, and HST is ten years old.  The gap is between them and
Mars Observer.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 23 May 90 17:05:18 GMT
From: swrinde!zaphod.mps.ohio-state.edu!mips!daver!tscs!tct![e-mail]  (Chip Salzenberg)
Subject: Re: NASA Headline News for 05/18/90 (Forwarded)

According to [e-mail] (Peter E. Yee):
>This is NASA Headline News for Friday, May 18....
>
>As current propulsion systems are unable to lift [Ulysses]
>directly from Earth over the sun's poles, a sling-shot trajectory
>around Jupiter will send the probe across the sun's equator in
>February, 1995.  The launch aboard the space shuttle Discovery is
>scheduled for October 5.

I wonder how Ulysses can go directly to Jupiter for its ally-oop
out-of-the-ecliptic assist, while Galileo must fly by Venus once and
Earth twice just to get to Jupiter and stay there.  Is orbital
insertion more exacting than a gravity-assist flyby?

On a related note, would any of the Soviet boosters be powerful enough
to send Ulysses up out of the ecliptic without help from Jupiter?
--
Chip Salzenberg at ComDev/TCT   <[e-mail]>, <uunet!ateng!tct!chip>

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

Date: 24 May 90 19:05:47 GMT
From: clyde.concordia.ca!mcgill-vision!quiche!calvin![e-mail]  (Mark SOKOLOWSKI)
Subject: Re: Manned mission to Venus

It is true that the movies are a good area of interest to me (and
it's true that I first only accepted the sci-fi ones as the only valid
type, for what is the use of showing real life situations when we already
have them around us???), but in any case I don't think that they should
be associated with a manned expedition on Venus. What I am thinking when
I imagine such an entreprise is the thrill of being there, the thrill of
doing something nobody else has ever done, like entering the athmosphere
of this planet at incredible speeds, then plunging to the surface through
the pure sulfuric acid clouds, and then landing, going outside,
taking photos, in short, living in surrealistic conditions in comparison
to which those on Mars and the Moon look like a beach party. And there
even more when you realise that this is a place just like the Earth,
with a horizon, mountains, valleys, (Ocean beds???) etc... just like
on our planet. Being there will simply make me feel better, and to satisfy
the desire to be there, I have all my adaptability and my technology.
When I read most of the postings in this group, I sometimes feel that
technology ends-up being pursued in itself, and not as a mean to realize
anything we want. Being on Venus is a realistic goal within the possibilities
of the techniques we have right now. It won't matter for me that Mars or the
Moon are more "realistic" targets, it will take tens of years to go there
anyway so why bother, I WANT TO GO TO VENUS!!!! PERIOD!!!!!

Mark S.
-------

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

Date: 24 May 90 05:39:57 GMT
From: sdd.hp.com!samsung!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: NASA Select TV

In article <[e-mail]> [e-mail] (David Young) writes:
>   I have seen quite a few  articles lately that mention NASA Select TV.
>Is that available to general cable subscribers or only via satalite?  ...

It is primarily distributed by satellite.  However, many cable companies
carry it, at least at times when something interesting is happening.
Ask your local cable people about it.
--
Life is too short to spend    |     Henry Spencer at U of Toronto Zoology
debugging Intel parts. -Van J.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 24 May 90 18:00:59 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!hepuxa.hep.uiuc.edu![e-mail]  (Ray Swartz)
Subject: Re: terraforming Venus

In article <[e-mail]> [e-mail] (John Sparks) writes:
>[time to let my ignorance show]...
>
>Doesn't our large moon account for the Earth not having an atmosphere like
>Venus? Or at least partially account for it?
>
>
>I think what Venus needs is a large moon like Earth has, to reduce the
>atmosphere. Or several smaller ones in a closer orbit should do the trick.
>Or several large asteroids in orbit.


    I have seen this belief in a science fiction story.  The way it
works is like this.  The earth's atmosphere has a density that is
basically a negative exponential from the surface on up .  Thus, there
is a part of the atmosphere even as high as the moon, it is just very
thin.  The moon, since the beginning of the system, has been sweeping up
some of this air and flinging it out into space by it's gravity.  Over
the past 4.5 billion years, this has reduced the earth's atmosphere so
it is no longer as thick as it once was (it started out like Venus).
So, the idea states, the earth needed the moon to become as hospitable
is it currently is (at least as far as the atmosphere goes).

    I think that this is a good example that one should not confuse
science with science fiction :-)


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Ray Swartz Jr.    |                                       |
Gradual Student   |  This space intentionally left blank  | When I get
U of Illinois     |---------------------------------------| a really
in the middle of  |  Hell, even _I_ don't want to claim   | good quote
a cornfield       |  these opinions as my own!            |
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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

Date: 24 May 90 18:23:18 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: DOD/NASA announce National Aero-Space Plane contractor team (Forwarded)

Mary L. Sandy
Headquarters, Washington, D.C                        May 24, 1990
(Phone:  [phone])                                       Noon

Maj. Robert Perry
Pentagon, Washington, D.C.
(Phone:  [phone])

RELEASE:  90-71

DOD/NASA ANNOUNCE NATIONAL AERO-SPACE PLANE CONTRACTOR TEAM

     The Department of Defense and NASA announced today the
immediate establishment of a national team of contractors to
continue the challenging research and development of the National
Aero-Space Plane (NASP).

     With the engineering and technology bases available from
Rockwell International, McDonnell Douglas, Pratt and Whitney,
General Dynamics and Rocketdyne, the federal government expects
to benefit from the synergism of ideas from these five
organizations.

     As a presidentially directed joint DOD/NASA program, the
NASP program objective is to develop technologies for a new
generation of aero-space vehicles.  This includes single-stage-
to-orbit space launch vehicles capable of horizontal takeoff and
landing and long range, hypersonic flight within the atmosphere.

     With the national contractor team, DOD and NASA take a
unique first step in formulating a single team of contractors
working together to develop technologies for future hypersonic
aircraft.  The team will conduct the design and development
activities for the X-30 research aircraft and develop a
competitive technology base for future systems.

     Instead of just one contractor coming forward with concepts
in materials, propulsion and structures, this new approach will
allow the government and the contractors alike to capitalize on
five industry bases of technological development.

     The government anticipates that with breakthroughs in
technology from efforts such as NASP, the United States will
continue to maintain its world leadership position in aerospace
technology.

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

Date: 24 May 90 18:22:28 GMT
From: spies!zorch![e-mail]  (Phil Gustafson)
Subject: Re: wooden ships

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>It wasn't uncommon for wooden ships to last only one major voyage, or for
>that matter for an expedition to come back with fewer ships than it started
>with, because of things like shipworm.


In fact, in Magellan's case only one ship of a small fleet made it home.
The saying among those who maintain historic wooden vessels [_Constitution_,
Victory_, etc.] is "After a hundred years you have either a replica or
a wreck."

I can sorta justify this comment in this group because so many shuttles
are named after historic exploration vessels.  I hope we eventually
have a _Fram_.
                phil

------------------------------------------------------------------------------
    Opinions outside attributed quotations are mine alone.
    Satirical material may not be specifically labeled as such.
------------------------------------------------------------------------------

--
  |  [e-mail]          | Phil Gustafson
  |  (ames|pyramid|vsi1)!zorch!phil      | UNIX/Graphics Consultant
  |                     | 1550 Martin Ave., San Jose CA 95126
  |                     | 408/286-1749

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

End of SPACE Digest V11 #448
*******************