Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_0/V12_040.TXT

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Subject: SPACE Digest V12 #40

SPACE Digest                                      Volume 12 : Issue 40

Today's Topics:
         Re: grim tidings for the future (wa
             Re: HST down and out
           Re: grim tidings for the future
              Re: Nasa's budget
           Re: grim tidings for the future
            Re: How to fix the HST
           Re: NSS protests Chinese launch pricing
               corruption etc.
             Re: Bush Approves Cape York
               Re: Light-ships

Administrivia:

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

Date: 8 Jul 90 18:56:00 GMT
From: swrinde!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu![e-mail]
Subject: Re: grim tidings for the future (wa


/* Written  6:46 pm  Jul  7, 1990 by [e-mail] in m.cs.uiuc.edu:sci.space */
1. Nobody is keeping space from being commercialized. [ ... ]
   There are no regulations preventing
   anyone from picking up a few surplus ICBM's and launching their own craft.
/* End of text from m.cs.uiuc.edu:sci.space */
Everything I've read about commercialization efforts indicate that there are
in fact _many_ regulations preventing people from just grabbing some ICBM's
and launching.

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

Date: 9 Jul 90 03:50:39 GMT
From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!f122.n249.z1.FIDONET.ORG![e-mail]  (Arnold Gill)
Subject: Re: HST down and out


 JK> Arnold, was the mirror ever checked out on the ground ???
 JK> Can't believe it was just put up there with on check out. on = no

      First of all, there are two mirrors, plus the rest of the optical system
that includes all of the various detectors - about 7 of them.  Second, Hubble
is designed to work in a micro-gravity environment, which means that it cannot
be tested as a complete unit on the ground - gravity would distort all of the
optics to make the test completely meaningless.

      That being said, the mirrors/instruments were tested individually, and
that seemed to come out fine.  Perkin-Elmer, who made the primary mirror, even
boasted that they had beat NASA specs on the grinding - check out a Sky &
Telescope from last year some time.  Now what does all of this mean?  No one
really knows where the error lies.  Steve Willner at Harvard-Centre for
Astrophysics is still guessing that it may *NOT* be a hardware problem, in that
the mirrors/instruments are exactly made as they were supposed to be.  Because
of the type of spherical abberation, and the fact that there are NO OTHER
optical problems, leads him to speculate that the problem is an integration
problem, i.e. the mirrors/instruments were not placed in the telescope casing
properly.

     But this is all speculation, and must be taken as such.  The simple answer
is that no one knows exactly what the problem is, and if they guess wrong and
make the wrong repairs during the 1993 shuttle refit flight (assuming the
shuttles are permitted to fly by then, but that's another story),then Hubble
will be having problems for a longer period of time.  However, be reminded that
NASA has an excellent track record of pulling a rabbit out of a hat when it
comes to rescuing seemingly dead spacecraft.  Voyager 2 was essentially dead
over 10 years ago, as they lost the primary transmitter, and the secondary lost
all frequency locking capabilities.  However, you have all seen the results
that NASA was able to obtain from this revived spacecraft.  There are a lot of
brilliant people there who I am convinced will find a work around to the
difficulties being encountered.
-----
   the Space(d) Cadet                    Astronomy Group, Queen's University


--- Maximus-CBCS v1.00
 * Origin: SilverSoft Support BBS [phone] <==> (1:249/122)




--
Arnold Gill
Internet: [e-mail]
BBS:      714 544-0934   2400/1200/300

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

Date: 9 Jul 90 21:10:40 GMT
From: uvaarpa!murdoch!astsun9.astro.Virginia.EDU![e-mail]  (Greg S. Hennessy)
Subject: Re: grim tidings for the future

In article <[e-mail]> [e-mail] (Derek Buzasi) writes:
#A poll (sic) of whom? Most astronomers are not extragalactic types, and
#thus do not fall into the category which most fervently supports HST.
#Most astronomers, if you take a moment to survey the field (you
#might check out, for example, the AAS's annual surveys) are photometrists
#and variable star people for whom HST is useless.

Interesting since I work mostly on extragalactic astronomy and I
always thought that HST was much better suited to stellar astronomers
than to extragalactic astronomers. The high speed photometer is a
GREAT instrument for these people. The fact that HST will focus the
light into a small point (ignoring the spherical abberation problem)
means that you can get a better estimate of the magnitude of the star
with the PC than you can get from  the ground. I would not call that
"useless".

--
-Greg Hennessy, University of Virginia
 USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
 Internet:      [e-mail]
 UUCP:        ...!uunet!virginia!gsh7w

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

Date: 9 Jul 90 21:55:35 GMT
From: mojo![e-mail]  (Doug Mohney)
Subject: Re: Nasa's budget

In article <[e-mail]>, [e-mail] (Allen W. Sherzer) writes:
>
>>For that matter, what will we do for a capsule?  Buy a Soyuz? (half :-) )
>
>For starters why not? With the man-rated Titan HLV and a Soyuz we wouldn't
>need the Shuttle anymore.

So how do we bring things back from space, such as satellites? I don't think
a communications satellite will fit in the air lock of a Soyuz, unless you
slide it up and take it in pieces ;-)

Like it or not, Shuttle has its place in the world. HOWEVER, having an
alternate capability to put people and things into orbit isn't necessarly
bad.

I think the Sovs won't sell just a Soyuz; they'd want to sell the whole
sheebang, from capsule to booster.

However, we did have this design called "Apollo" which worked really well.
Maybe someone (and I think the Laser-Launching people are doing this) will
give us an Apollo '90, using the best of composites, advanced design materials
and electronics. OR, maybe not, but an Apollo '90 which is engineered to
be "mass-produced." With a special emphasis on a Cargo-Apollo (When in
doubt, borrow an idea from the Comrades!)

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

Date: 9 Jul 90 22:40:33 GMT
From: hao.hao.ucar.edu![e-mail]  (Derek Buzasi)
Subject: Re: grim tidings for the future

In article <[e-mail]> [e-mail] (Greg S. Hennessy) writes:
>In article <[e-mail]> [e-mail] (Derek Buzasi) writes:
>#A poll (sic) of whom? Most astronomers are not extragalactic types, and
>#thus do not fall into the category which most fervently supports HST.
>#Most astronomers, if you take a moment to survey the field (you
>#might check out, for example, the AAS's annual surveys) are photometrists
>#and variable star people for whom HST is useless.
>
>Interesting since I work mostly on extragalactic astronomy and I
>always thought that HST was much better suited to stellar astronomers
>than to extragalactic astronomers. The high speed photometer is a
>GREAT instrument for these people. The fact that HST will focus the
>light into a small point (ignoring the spherical abberation problem)
>means that you can get a better estimate of the magnitude of the star
>with the PC than you can get from  the ground. I would not call that
>"useless".
>
Actually, for precision photometry one generally doesn't want to focus
light into a small point, because this amplifies pixel-to-pixel (or
the equivalent) irreularities in one's detector. Better to spread the
light out and average over these variations.

The good part, for photometrists, about being in space is that scintillation
noise is eliminated. The bad part is that the amount of time available
to photometrists on HST is incredibly small in comparison to the problems
awaiting solution. How can one derive accurate light curves for objects
with 30-day periods when that might require several dozen pointings of
the telescope? The TAC simply will not grant time for such a request.
Stellar oscillations similarly cannot be effectively studied because of
the long observing runs required.


>--
>-Greg Hennessy, University of Virginia
> USPS Mail:     Astronomy Department, Charlottesville, VA 22903-2475 USA
> Internet:      [e-mail]
> UUCP:        ...!uunet!virginia!gsh7w


--
******************************************************************************
Derek Buzasi                     *    "History is made at night.
High Altitude Observatory        *     Character is what you are in the dark."
[e-mail]                 *             -- Lord John Whorfin

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

Date: 9 Jul 90 03:40:51 GMT
From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!turnkey!orchard.la.locus.com!snap.la.locus.com!snap.la.locus.com![e-mail]  (Richard M. Mathews)
Subject: Re: How to fix the HST

[e-mail] (Tom Neff) writes:

>In article <[e-mail]> [e-mail] (Mark SOKOLOWSKI) writes:
>> ... It's simply that by 1993, the technology
>>of ground-based telescopes and their effective power will literally make
>>the HST absolete, even if it can by then have the perfomances we expect
>>from it _NOW!!!_. I remember having read an article in a european science
>>magazine (I think it was Science & Vie from France) that proved quite
>>clearly that the small HST's aperture (2.4m) isn't quite capable of
>>matching the power gathering abilities of the most recent ground-based
>>projects (like some 10m scopes in Chile, a few 6-15m in aperture scopes
>>linked for interferometry in some other places etc...).

I don't have the original version of the above message, just this extract.
I'm sorry if lack of context has caused me to misinterpret anything....

There is more to consider than light gathering power.  Besides the fact
that a ground based scope can't see IR or UV, the HST will surpass (or
would have surpassed) ground based scopes in resolution.  For some kinds
of objects, even the uncorrected HST will be capable of good resolution.
The following quote discussing the 10m Keck scope is from the July S&T
(before knowledge of the HST optics problem, of course).

    "Keck and HST will actually reach the same stellar magnitude
    in visible light, 28 or so," comments [Keck project scientist,
    Jerry] Nelson.  "HST does it by better resolution.  Keck will do
    it, in spite of poorer seeing on the ground, because it collects
    so much more light.  For resolution of small bright objects HST
    wins hands down, of course.  But in the spectroscopy of faint
    extended objects, like very remote galaxies, Keck will just
    _swamp_ HST." [S&T's emphasis]

HST will not be obsolete in '93.

Richard M. Mathews
Locus Computing Corporation
[e-mail]
lcc![e-mail]

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

Date: 9 Jul 90 20:53:20 GMT
From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (David Anderman)
Subject: Re: NSS protests Chinese launch pricing

Where were these people when the shuttle was launching commercial
satellites for $5 million a pop?


--
David Anderman
Internet: [e-mail]
BBS:      714 544-0934   2400/1200/300

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

Date: 10 Jul 90 03:19:20 GMT
From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: corruption etc.

In article <[e-mail]> [e-mail] writes:
>I think most of the people on this list are failing to appreciate just
>what is going on over there in the U.S.S. of R. Democratization, that's
>what! And what does that mean to us? It means that soon they too will
>have corruption at all levels of government...

They already do, actually.

It might, just possibly, be under slightly better control, given that
it carries the death penalty there.
--
NFS is a wonderful advance:  a Unix    | Henry Spencer at U of Toronto Zoology
filesystem with MSDOS semantics. :-(   |  [e-mail]   utzoo!henry

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

Date: 9 Jul 90 03:59:31 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!uniwa!vax6![e-mail]  (Liam E. Gumley)
Subject: Re: Bush Approves Cape York

In article <[e-mail]>, [e-mail] (Michael Saleeba) writes:
>
> I think what they really mean here is just "competition" :->
>
> BTW: Does anyone know why the Cape York site was chosen? I know that
> environmental groups have been gearing up to get really upset about this
> choice of site. After all, Cape York is a relatively unspoilt site. If
> there is going to be a lauch site in Oz, why not make it at the old Woomera
> site, which has a number of advantages. For a start it is already established,
> albeit rather abandoned at the moment. Secondly there is little chance of
> environmental concern as it is in the middle of the desert and is pretty
> messed-up already. And finally it has an extremely cool name; a woomera is
> an Australian Aboriginal spear-thrower :-)
>
>

As I understand it, the Cape York site was chosen as it is closest to the
equator, thus making for the most efficient launches as you have a big
assist from the earth's rotational speed.  You don't get anywhere near this
advantage at the Woomera site.  I think the only reasons for putting it at
Woomera would be historical rather than practical.  I heard that the whole
project still depends on the results of an environmental impact statement
which could take up to a year to generate.

Let's face it, Cape York is quite isolated, and I'm sure the spaceport could
be built to minimise the impact on the surrounding area.  Perhaps
someone might like to comment on how the wildlife that live inside the
boundaries of Kennedy Space Center respond to the activity around them.

I guess I can see the environmentalists viewpoint that any development
whatsoever spoils the whole place, but then again the spaceport would mean a
significant increase in launch capabilities for both commercial and
scientific purposes (I doubt the U.S. or anyone else will be launching
defense satellites from there).

Anyhow, that's just what I reckon.

Cheers,
Liam.

===============================================================================
| Liam E. Gumley                     "We've gone completely crazy!"   _--_|\  |
| Department of Applied Physics      - the Dodgey Brothers.          /      \ |
| Curtin University of Technology                                    \_.--._/ |
| Perth, Western Australia.                                                v  |
| Internet:[e-mail]                I think, therefore,      |
| Bitnet:[e-mail]    all opininons are my own.|
===============================================================================

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

Date: 9 Jul 90 16:38:09 GMT
From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!watserv1!maytag!watdragon!lion![e-mail]  (Mike Harrison)
Subject: Re: Light-ships

In article <[e-mail]> [e-mail] writes:

>What are some of the other ideas for unconventional ways to 'space-out'?

Dr. Robert L. Forward has an article in the August Analog magazine on the
possibility of using negative matter in constructing a pollution-free
fairly efficient space drive. (negative matter is matter with negative
mass as opposed to matter with positive mass) He first justifies the
that there is nothing that says negative matter doesn't exist, then
describes the physics in detail. (I'm no physics expert, so please don't
flame me :)) Of course, the only thing preventing this idea from becoming
reality is the fact that nobody has discovered any negative matter yet.

Mike

--
Mike Harrison                | "...because they drink a lot in Hamburg, and at
[e-mail] |  night, you can skate home in other people's
[e-mail]|  sick." -- Dieter, SNL (Why I Like Hamburg)

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

End of SPACE Digest V12 #40
*******************