Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_437.TXT

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Subject: SPACE Digest V12 #437

SPACE Digest                                     Volume 12 : Issue 437

Today's Topics:
        Re: Cost comparison: Apollo/Saturn vs. Shuttle
                Hubble
                 Space Digest
                Re: Space GIFs
           Payload Status for 10/09/90 (Forwarded)
            Re: Magellan Update - 10/09/90
              Re: Iron asteroid in orbit
                   Re: HST

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 8 Oct 90 16:48:32 GMT
From: convex!convex.convex.com![e-mail]  (Edward V. Wright)
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle

In <[e-mail]> [e-mail] (Karl Stapelfeldt) writes:

>If we want to make a fair cost comparison between Apollo/Saturn and the
>Space Shuttle, we should compare the costs of a Saturn 1B low Earth orbit
>mission against the cost of a space shuttle mission.  Some data on the
>Saturn 1B appears below.  These figures are the recurring costs for
>hardware only, taken from written testimony to the Senate Appropriations
>Subcommittee during hearings on the FY 1972 NASA budget (p. 887).
>The costs are in 1971 dollars.

>    Saturn 1B rocket and instrument module   $ 42 million
>    Command & Service modules                $ 55 million

>Putting in a factor of 3 for inflation, this implies that each Saturn 1B
>mission cost about $ 300 million in today's dollars -
>** just to buy the flight hardware **.

>    I assume mission operations costs are about equal for the Shuttle and
>Saturn 1B.

Not even close.  Look at the NASA budget, then divide the amount
spent on Shuttle-related items by the actual number of Shuttle
flights.  You will find that NASA spends over $500 million on each
Shuttle flight, *not even including* R&D and hardware costs which
NASA has already written off.

Some other problems with your analysis:

>    Saturn 1B rocket and instrument module   $ 42 million
            ^^            ^^^^^^^^^^ ^^^^^^

The Saturn 1B was a fairly primitive, interim vehicle proposed
in limited quantities. The Saturn V was much larger and much
cheaper on a per-pound-of-payload basis. Plans existed for low-cost
Saturn derivitives to carry a wide range of payload sizes.

As far as the instrument module is concerned, you're talking about
an airborne computer that weighed several tons and had (if memory
serves me right) about 16K RAM.  I think we could do a little bit
better today. :-)

>It is also clear that the space shuttle is a far more capable system
>in low Earth orbit than an Apollo Command/Service Module: More crew can
>be carried, much more room for experiments, ability to retrieve payloads.

The Big Gemini spacecraft, designed to fly on an Int-20 launch vehicle
(first and third stages of the Saturn V) could carry 16 crew and passengers.


>and a plain crew capsule is no bargain if you plan on flying people
>repeatedly to LEO.

The Air Force recovered, refurbished, and reflew an (unmanned) Gemini
spacecraft. There were plans to do the same thing with Apollo s/c before
the program was cancelled.

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

Date: Tue, 9 Oct 90 21:52 EST
From: [e-mail]
Subject: Hubble

I just picked up the "Space Shuttle Operator's Manual" at a local
bookstore... great stuff for us sub-technical types.  In the write-up
about the Space Telescope (pre-launch; "SSOM" was published in '88),
it is specifically stated that Hubble is designed to be able to be
retrieved by the Shuttle for repairs or improvements.  My question:
why the big fuss about the problems with the Hubble if it's retrievable?
Or is the problem simply that there's too much work and too few Shuttles?

                                        Mark F. Jenkins
                                        Bowling Green State University

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

Date: Tue, 9 Oct 90 12:54:56 CDT
From: mrsvr!master.mrisi![e-mail] (Steven Davis)
Subject: Space Digest

Moderator:

Please put me on the mailing list for Space Digest.

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

Date: 9 Oct 90 02:51:14 GMT
From: sumax!amc-gw!thebes!polari![e-mail]  (Paul Varn)
Subject: Re: Space GIFs

Since my orriginal request for a source of space related GIF format pictures,
there has been mail sent to me by others interested in the same thing.
The only source posted here so far is the reference to shuttle pictues.
The site: wuarchive.wustl.edu was mentioned as a possible ftp site but more
information is needed to reach the file server there (if there is one).
I appreciate any information on this subject that appears over the net.
-PV-
     /+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+\
     +   COMMENTS COMPLIMENTS CONTINOUS COMPLAINTS   +
     "             COURTESY: Paul Varn               "
     +   UUCP: pv@polari             GEnie: p.varn   +
     \+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+/

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

Date: 9 Oct 90 03:02:35 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 10/09/90 (Forwarded)


    Daily Status/KSC Payload Management and Operations 10-09-90.


    - STS-35 ASTRO-1/BBXRT (at pad-ba)

    Payload support for SSV rollback to VAB continues.


    - STS-41 Ulysses (in flight)

    No work is scheduled for today.


    - STS-38 DoD MMSE support (at VPF)

    Canister sensors will be replaced today.


    - STS-39 AFP-675/IBSS/STP-01 (at ccafs)

    Ground software development continues.


    - STS 40 SLS-1 (at O&C)

    Module closeouts continue.


    - STS-37 GRO (at PHSF)

    No work is scheduled for today.


    - STS-42 IML-1 (at O&C)

    Module and experiment staging continue.


    - STS-45 Atlas-1 (at O&C)

    Experiment and pallet staging continue.


    - STS-46 TSS-1 (at O&C)

    Pallet staging will continue today.


    - STS-47 Spacelab-J (at O&C)

    Rack staging continues.


    - STS-67 LITE-1 (at O&C)

    No work is scheduled for today.


    - HST M&R (at O&C)

    Development of the ADP for shipment of the M&R pallet to
    GSFC continues along with PETS preparations.

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

Date: 9 Oct 90 20:11:53 GMT
From: uc!noc.MR.NET!msi.umn.edu!umeecs!umich!caen!sol.ctr.columbia.edu!emory!hubcap![e-mail]  (Sandi Piazza)
Subject: Re: Magellan Update - 10/09/90

>
>      The Magellan spacecraft has now completed 177 mapping orbits of Venus,
> with good radar data recieved from at least 173 orbits.  Spacecraft systems

  This is probably a dumb question, but I'll ask anyway.  What is going to
  be done about getting the information missed in the 4 orbits for which
  there was no good data received?

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

Date: Tue, 9 Oct 90 12:41:41 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: Iron asteroid in orbit


>From: uceng![e-mail]  (daniel mocsny)

>Small asteroids (1 km dia.) don't lose much speed
>before hitting the ground. If you parked one in LEO, you'd have
>to let it down in pieces.

Actually, given the low price of most of the metals, it's hard to come up
with anything to *do* with a huge chunk of iron that you couldn't do cheaper
by digging and refining your own ore. It's much easier to break up a big chunk
of rock than an equivalent piece of iron. Sawing is possible, but slow and
probably too expensive. An electric arc or an oxygen torch *might* be
economical, but a pulsed laser probably not. Crushing is out of the question,
as are explosives. (Not even fission bombs would have much effect.)

>Here is a question for would-be space miners: if you had a nice
>Ni-Fe asteroid parked in LEO and you wanted to bring down, say,
>500,000 tons of it per year, would you be better off:

The answer's so obvious, and yet nobody ever mentions it. Simply divide the
material into convenient pieces, shape them if necessary, and attach
maneuvering controls. The chunks fall through the atmosphere, and are carefully
guided right into the bore of your electromagnetic launcher! At this point
it is a simple matter to operate the launcher backwards, to decellerate the
payload. You might even be able to recover some energy from the operation.

:-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-)

    John Roberts
    [e-mail]

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

Date: Tue, 9 Oct 90 14:45:12 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: HST


>From: usc!samsung!umich!csd4330a!osl380a![e-mail]  (Ken Ellis)
>Subject: Re: HST

>I am interested in interferometric imaging at short wavelengths and would like
>to find out more. I am familiar with the interferometric imaging work at UC,
>Berkeley and at the University of Illinois, but not at Georgia. Could you point
>me to some references or tell me who is doing the work? Thanks.

>Ken Ellis
>[e-mail]

I received several requests on this, so I had to go look it up. Fortunately,
I had not yet deleted the references, some old SPACE messages in a discussion
on HST theoretical resolution. In answer to your question, it's the Center
for High Angular Resolution Astronomy, Georgia State University (Atlanta).
Here are some of the old messages:

.............................

Date: 9 Mar 90 19:57:12 GMT
>From: zaphod.mps.ohio-state.edu!swrinde!emory!emcard!wa4mei!nanovx!chara![e-mail]  (Donald J. Barry)
Subject: Re: Resolving Power of Hubble Space Telescope

As stated correctly by several posters, the HST will have a limiting
performance of 0.1 arcseconds.
[Actually, better than that, after correction of optics - JWR]

What was not mentioned is that resolution three times greater is
routinely obtained through ground-based optical speckle inter-
ferometry.  Using the 4-m Mayall and CTIO telescopes, the Center
for High Angular Resolution Astronomy (CHARA) at Georgia State University
routinely resolves features down to 0.03 arcseconds.  Statistical
techniques to remove atmospheric blurring are used with sensitive
detectors capable of taking short exposures over which atmospheric
distortion is frozen.  Many such images are processed to yield a
final diffraction-limited dataset.

Arrays of optical telescopes are being pioneered by several groups,
including CHARA.  The "CHARA Array", a network of 7 1-meter
telescopes distributed over a 400-meter circle, is currently
under consideration for funding by the National Science Foundation.
The Array will have a limiting resolution of 0.2 milliarcseconds -- a
factor of 100 exceeding any ground-based instrument (and 300 times
better than Hubble!)

Of course, these techniques are limited to reasonably bright
sources (New detectors enable the speckle technique to work to
roughly 14 magnitude, over a dynamic range not exceeding 100/1, and
the Array will have limiting magnitude of 11 initially, and 14 with
optical compensation)  But there are many interesting objects visible
with these constraints -- certainly far more than Hubble will ever have
time to examine.

Hubble's principle contribution will be simultaneous solution of several
limits pertaining to ground-based astronomy -- fine resolution of
very dim sources having large dynamic ranges, in visible and UV.
Singly, except for UV spectroscopy, the capabilities of HST have
been duplicated years past by ground based instruments.
--
Donald J. Barry       [phone]         | [e-mail]
Center for High Angular Resolution Astronomy | President, Astronomical
Georgia State University, Atlanta, GA 30303  | Society of the Atlantic

..............................

Date: Wed, 14 Mar 90 13:55:27 +0100
>From: [e-mail] (Daniel Fischer)
Subject: Re: Resolving Power of Hubble Space Telescope

...
  Don Barry also mentioned:
> The "CHARA Array", a network of 7 1-meter telescopes distributed over a 400-
> meter circle, is currently under consideration for funding... The Array will
> have a limiting resolution of 0.2 milliarcseconds..., and the Array will have
> limiting magnitude of 11 initially...
Don't forget the Very Large Telescope the European Southern Observatory *has*
already funded: somewhere in Chile 4 telescopes, each with 8-meter mirrors, will
be able to work interferometrically with a 100-meter baseline around the year
2000. This interferometer will have a limiting magnitude of approx.15 (some be=
lieve: 18) - image reconstruction, again, already 'works' in striking computer
simulations. And each of the 8-meter telescopes will also support a speckle
camera that might give 0.01 arc sec images down to 20th magnitude. So there you
have it, the *big* step forward the Edwin P.Hubble Space Telescope actually
represents: it gives you 1/100 arcsec resolution, 28th or fainter limiting
magnitude and UV light *at*the*same*time*. Both high resolution and faint stars
you can get from the ground by now (ESO's New Technology Telescope gets to 27 in
just one hour - and it has just a good 3.6-meter mirror), but not simultaneous=
ly: that's why a 'son of HST' with at least 10-meters diameter is already under
consideration, be it in geostationary orbit or on the moon.

+- [e-mail] --- Daniel Fischer --- [e-mail] -+
| Max-Planck-Institut f. Radioastronomie, Auf dem Huegel 69, D-5300 Bonn 1,FRG |
+----- Enjoy the Universe - it's the only one you're likely to experience -----+

..............................

Date: 18 Mar 90 19:08:58 GMT
>From: mephisto!eedsp!chara![e-mail]  (Donald J. Barry)
Subject: Re: Resolving Power of Hubble Space Telescope

Dan Briggs-  Your point is well taken; I suppose we all are proud of
our achievements in the field, and sometimes our claims take on
a tone of superiority.

Dan Fischer -- we are not studying stellar diameters -- I think
you are confusing our speckle work with that of John Davis, et al.
and the Narrabri Stellar Interferometer of the early 70's.  The
current speckle interferometry work is that of binary surveying -- we
have spent some 150 observing nights on 4-m class instruments over
the last ten years, making some 11,000 measures of binary stars.  We
are determining visual orbits to integrate with spectroscopic orbits
to study mass functions, distance scales, and stellar evolution.  The
data is not processed with true imaging techniques, but rather limited
imaging techniques that make use of the knowledge of the source as a
collection of points.  We have done true imaging, using modifications
of "Shift and Add" (Bates, 1978), but have avoided to date Knox-Thomson
because our camera is probably too noisy to give us good convergence.
Until we have better reproducibility in this realm of processing,
though, we won't publish -- we've got enough stellar papers in the
works, anyway.  (Do you feel as I do that too many people are publishing
imaging results with poor reproducibility?)

The array interferometer we consider likely to be funded within this
year -- if so, we'll have first light through it by the beginning of
1994.  The magnitude limits will not be so impressive as those you
claim for the VLT and its cousins, but those numbers also assume
workable development of adaptive technology which is still in its
infancy.  We are trying to be conservative until this exciting
technology is better known.  In any events, the instruments will
complement one another -- the VLT array in light grasp, and the
CHARA array in resolution.  John Davis' proposed array in Sydney
will yield yet greater resolution, but at lower (magnitude 8) limit.

Although speckle masking permits easier phase identification, and
makes reconstruction algorithms much more robust, it's good to
remember that Fienup showed that almost every type of source can
be reconstructed unambiguously from intensity information alone.

I'll wait expectantly to hear the progress of the interferometric
capability on ESO's new telescopes.  This is an exciting, growing
field for all of us.  Best of luck with your progress.

--
Donald J. Barry       [phone]         | [e-mail]
Center for High Angular Resolution Astronomy | President, Astronomical
Georgia State University, Atlanta, GA 30303  | Society of the Atlantic

.................. End of old messages ................

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

End of SPACE Digest V12 #437
*******************