Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_6/v16no614.txt

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Date: Sun, 23 May 93 05:08:52
From: Space Digest maintainer <[e-mail]>
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Subject: Space Digest V16 #614
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Space Digest                Sun, 23 May 93       Volume 16 : Issue 614

Today's Topics:
                  Boeing TSTO concept (sort-of long)
                  Hey Sherz! (For real!) Cost of LEO
How useful is visible light astronomy (was space marketing billboard)
                          Moon Base (2 msgs)
                     Space Billboards at Hi-Cost
            Space Marketing would be wonderfull. (3 msgs)

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Date: Sat, 22 May 1993 19:17:32 GMT
From: "Richard A. Schumacher" <[e-mail]>
Subject: Boeing TSTO concept (sort-of long)
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>more adept at that in recent years. Active cooling for the necessary
>short dashes might be easiest, but even Shuttle tiles or thermal blankets
>might do for passive protection.

These would be No Fun on surfaces intended to create lift. Yes, I
know there are tiles on the Shuttle wings; the Shuttle lifts like
a brick. (Trivia question: how fast would a Shuttle have to move
to actually gain altitude using only its wings?) Not to mention
the servicing required if the craft did survive a trip.



>(I know, bite your tongue for mentioning
>off the shelf Shuttle pieces.)

Ones that work, sure. Come to think of it, is there any Shuttle-specific
hardware or Shuttle-derived technology that one would choose to re-use in
a flight system, if one had a choice?

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

Date: Sat, 22 May 1993 21:05:12 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Hey Sherz! (For real!) Cost of LEO
Newsgroups: sci.space

In article <1tkk7q$[e-mail]> [e-mail] (Ken Hayashida) writes:

>Allen Sherzer posted:
>>...A resurrected Saturn would cost only $2,000 per pound
>>(if development costs are ignored) which is five times cheaper than Shuttle.

>Allen,
>Exactly what are you describing here?  manufacturing?  Assembly?
>Cost to government?  launch facilities?  hiring workers and training
>them?

That represents the total cost of putting a pound into LEO (ignoring
development costs of $12.59B) with a restarted Saturn launcher in a
lot of 50 launches. A single launch would cost about $3,500/pound.
(All costs are in 1991 $$).

>Please post your source for this estimate.

"Use of Saturn V as an HLLV Option", a presentation before the House
Science Space Subcommittee by Ronald Harris of the NASA Office of Space
Flight on March 14, 1991.

>I am most interested in the
>exact source of your projection because I am attempting to calculate
>the total number of pounds of payload Saturn V inserted in to LEO.

I think actual numbers are less important than capabilities and costs.
But accounted for the same way, Saturn would win hands down. Better
still, there are vehicles which could beat Saturn.

>I think I have a fair way to compare the cost per mass into LEO.
>For each system I will do the following:

>MASS CALCULATION
>~~~~~~~~~~~~~~~
>Saturn V mass to orbit:
>Mass of S-IV-B upper stage, LEM with shroud, C-SM and escape tower.

A restared Saturn would lift 260,000 pounds to LEO. That is the only
figure that matters.

>STS/shuttle mass to orbit:
>Mass of the orbiter plus payload in the bay.

The mass of the orbiter is a pointless thing to consider. A launcher which
lifted a million pounds to LEO but only one ounce of payload would win
your contest but would be a pretty useless operational launcher.

The only figures of merit are capability and cost.

>COST CALCULATION
>~~~~~~~~~~~~~~~~
>HELP:  If someone out there is an economist and can help me compare dollars
>from FY 1967 and FY 1991,

In 1991 $$, the original Saturn development costs where $16.18 billion. To
begin production again, an additional $12.25B would be needed. In single
quanity Saturn would cost $860M per launch and $590M per launch in lots
of 50 launches. These vehicles would lift 260,000 to LEO.

That should be all you need for your Saturn calculations. However, I
would add interest charges to my estimates (although this makes Shuttle
people mad since it roughly doubles the costs).

For Shuttle, total costs for the first 4 vehicles where roughly $25B
in 1986 $$. Figure $30B in 1991 $$. Each flight lifts roughly 50,000
pounds and costs about half a billion $$.

Any way you cut it, Shuttle is the big looser.

   Allen
--
+---------------------------------------------------------------------------+
| Lady Astor:   "Sir, if you were my husband I would poison your coffee!"   |
| W. Churchill: "Madam, if you were my wife, I would drink it."             |
+----------------------25 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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

Date: Sat, 22 May 1993 18:36:31 GMT
From: Frank Crary <[e-mail]>
Subject: How useful is visible light astronomy (was space marketing billboard)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Anita Cochran) writes:
>> Exactly what fraction of current research is done on the big,
>> visable light telescopes? From what I've seen, 10% or less
>> (down from amlost 100% 25 years ago.) That sounds like "dying"
>> to me...

>...If you look at the Astrophysical Journal or the Astronomical
>Journal, you will note that the majority of the data being used is
>visible light or near infrared...

"...or near infrared" changes my statement quite a bit. I said
visible, not visible and near IR. I've seen alot of papers on
near IR work, especially now that adaptive optics are possible
that these wavelengths.

>> That would be true, if adaptive optics worked well in the visable.
>> But take a look at the papers on the subject: They refer to anything
>> up to 100 microns as "visable". I don't know about you, but most
>> people have trouble seeing beyond 7 microns or so... There are
            Should read .7 microns
>> reasons to think adaptive optics will not work at shorter
>> wavelengths without truely radical improvements in technology.

>Despite the fact that Frank Crary claims to have a degree in astrophysics
>from Berkeley, he does not know what he is talking about here.
>NO ONE calls things to 100 microns the visible.  In fact, 100 microns is
>the FAR infrared.

100 microns might be an exageration, but proposals for adaptive optics
telescopes claim to be "optical" instruments, and the refer to
resolving power at wavelenghts well beyond the near IR. By implication
they are claiming that most of the infrared is "optical" and creating
(inaccurate) impression about the abilities of adaptive optice in the
visible.

>It is true that it is easier to do adaptive optics at infrared wavelengths
>than visible wavelengths since the isoplanetic patch is larger and therefore
>fewer actuators are necessary.

That isn't the only problem. The time scales on which corrections must
be made are shorter, the required accuracy of the corrections is
greater, etc...

>...However, the laser guide star program
>at LLNL and Kirtland are both working in the visible.  It can and IS
>being done in the visible.

For small apatures and first order corrections.

>> I find that claim hard to believe: A _peak_ brightness or size
>> along these lines is possible, but since we are talking about
>> something at a height of only 300-500 km, the brightness would
>> drop off sharply if it were away from the horizon. (as sec(z)^2)
>> You would have to be almost underneath it for it to get a
>> significant amount of scattered light.

>Well, I don't know the particulars about the space billboard proposal.
>All I know about it comes from the press release of May 13 of the
>American Astronomical Society (the professional society for US
>astronomers).  This press release reads (all typos mine):

The press release you cite is devoid of details and what little
specifics it states are entirely consistant with my above remarks.

                                                  Frank Crary
                                                  CU Boulder

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

Date: Sat, 22 May 1993 19:25:09 GMT
From: Nick Janow <[e-mail]>
Subject: Moon Base
Newsgroups: sci.space

[e-mail] (Les Kirk) writes:

> Could the shuttle be outfitted with the necessary oxygen to make a trip
> back to the moon possible?  I certainly do not see why it couldnt be.

That seems a bit silly.  The shuttle is designed as a surface-orbit-surface
vehicle.  Why waste it on a task that it isn't designed for, which can be
better handled by a simpler vehicle.  A Earth-moon transfer vehicle isn't as
simple as "sticking some engines on a shuttle external tank", but it doesn't
need the fancy hydraulics, powerful engines, strong structure, etc, of the
shuttle.

> Anyone have any ideas on this subject?

I like the idea of building an aluminum/oxygen extraction facility on the
moon. This could provide for relatively inexpensive support for other
projects.  The aluminum could be used for structures, and the oxygen for life
support, on the moon or in Earth orbit.  The Earth-moon transfer vehicle
could be fueled with oxygen and molten aluminum.  Al-O batteries could
provide power away from the main perated solar cell facility?

If the government(s) built the initial Al-O facility and made the products
available for other projects at reasonable cost, other projects might become
economically viable.

--

[e-mail]

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

Date: Sat, 22 May 1993 16:42:47 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Moon Base
Newsgroups: sci.space

In article <[e-mail]> you write:
>Does NASA or any other private firm have plans to construct a moon base?
>
>I for one would love to see a base constructed and inhabited by a wide
>variety of people.  The technology exists today to make such an adventure
>plausible I'm sure.
>
>Could the shuttle be outfitted with the necessary oxygen to make a trip
>back to the moon possible?  I certainly do not see why it couldnt be.
>
>If missions are now lasting as much as 4 to 7 days, why could they not
>last an extra 4 to 7 days and then return?
>
>Anyone have any ideas on this subject?

This comes up at least once a month. In short, the Shuttle's SSMEs
can't be restarted in orbit, they don't have any fuel anyway since
the *empty* external tank is discarded on the way up, and the Shuttle
needs atmosphere to land, it's a glider and the Moon has no atmosphere.
So even if you found some way to supply a fuel tank, fill it, and
cobble up a way to restart the engines, you still couldn't land when
you reached the Moon. Not to mention it isn't efficient to lug along
an extra 40 kilopounds of Orbiter for a jaunt to the Moon. What you
want is an orbit to orbit transfer vehicle, no wings, no streamlining,
nor any other extraneous stuff, and a LEM, a lunar lander that can
transfer crew and supplies from lunar orbit to lunar surface and
back. We know how to build those, we've done it before. Making it
*reusable* so it can be left at Luna is the trick to making it
efficient. We haven't done that yet.

We could dock a LTV (Lunar Transfer Vehicle) at Freedom (or MIR)
between uses.  We'd only need to transfer fuel, crews, and supplies
up and down from Freedom (or MIR) orbit by Shuttle (or Progress). The
LEM could stay at the lunar base between flights and be partially
refueled from native propellants (need to ship in hydrogen).

Some would claim that the proposed DC-1 could be refueled in orbit
and go to the Moon direct. That's an alternative, but timing would
be a lot more tricky. Better would be a modified DC style craft
designed for the Earth-Luna run and based at a station.

The more pressing question though is "Why go back to the Moon?"
The general public says "Been there, done that." And there seems
little commercial justification. There are certainly more interesting
scientific targets. Mars for one, minor planets and comets for others.

Gary
--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     |

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

Date: Sat, 22 May 1993 21:51:43 GMT
From: Karl Hahn <[e-mail]>
Subject: Space Billboards at Hi-Cost
Newsgroups: sci.astro,sci.space

Here's an idea a roommate and I came up with about 20 years ago.

First you cover a large unused land area with mirrors.  The mirrors
would be each angled for a focus on the moon.  Then you wait for
the next total lunar eclipse.  While the eclipse was going into
totality, you have an enormous fleet of aircraft leave a pattern
of colored smoke over the mirrors.  Once they are out of the way,
an ICBM explodes a 20 megaton bomb hundreds of miles above the whole
thing and --

Presto!  There's the Coca Cola logo projected onto the moon for
half the world to see...

We were very drunk at the time.

         (V)              |  "Henceforth, Wendy knew that she must grow
   (^    (`>              |   up.  You always know after you are two.
  ((\\__/ )               |   Two is the beginning of the end."
   \\<   )   der Nethahn  |
    \<  )                 |   J.M. Barrie
     ( /                  |
      |                   |

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

Date: Sat, 22 May 1993 18:18:31 GMT
From: Frank Crary <[e-mail]>
Subject: Space Marketing would be wonderfull.
Newsgroups: sci.environment,misc.consumers,sci.astro,sci.space,rec.backcountry,misc.headlines

In article <[e-mail]> [e-mail] (Paul E. Reimer) writes:
>>The _only_ difference between this structure and any other proposed
>>space structure is that this one would contain a commercial message.
>>It might say "Coke" instead of "NASA".

>I can't read the word "NASA" from the ground, in fact, I have to strain
>to descern those satelites.

If the proposed space station, Freedom, were built, you wouldn't
have any trouble making it out as a man-made object. It would look
like a "I", not like a point of light. Does the fact that it would
be a government, rather than a commercial, project mean would not
be disrupt the pristine sky?

                                                Frank Crary
                                                CU Boulder

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

Date: Sat, 22 May 1993 18:24:11 GMT
From: Frank Crary <[e-mail]>
Subject: Space Marketing would be wonderfull.
Newsgroups: sci.environment,sci.astro,talk.environment,talk.politics.space,sci.space

In article <[e-mail]> [e-mail] writes:
>fc> That would be true, if adaptive optics worked well in the visable.
>fc> ...There are
>fc> reasons to think adaptive optics will not work at shorter
>fc> wavelengths without truely radical improvements in technology.

> Hmm, some of the folks in this department planning on using
> adaptive optics at the 5 m at Palomar for near-infrared
> observations (1 and 2 microns) might be surprised to hear this.

Unless they can see 2 micron light, I don't think they would be
(I said visible, not near IR...) Also, are they going to do anything
beyond first order corrections? That alone is a big improvement, but
not nearly as good as the higher-order corrections possible at
greater wavelengths.

> And isn't the NTT already pushing toward 0.1 arcsecond resolution,
> from a ground-based site (remember 0.1 arcseconds was one of the
> selling points of HST).

Probably, but at what wavelength?

                                                  Frank Crary
                                                  CU Boulder

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

Date: Sat, 22 May 1993 21:00:11 GMT
From: "Scott D. Young" <[e-mail]>
Subject: Space Marketing would be wonderfull.
Newsgroups: sci.environment,misc.consumers,sci.astro,sci.space,rec.backcountry,misc.headlines

In <[e-mail]> [e-mail] (Frank Crary) writes:

>In article <[e-mail]> [e-mail] (Paul E. Reimer) writes:
>>>The _only_ difference between this structure and any other proposed
>>>space structure is that this one would contain a commercial message.
>>>It might say "Coke" instead of "NASA".

>>I can't read the word "NASA" from the ground, in fact, I have to strain
>>to descern those satelites.

>If the proposed space station, Freedom, were built, you wouldn't
>have any trouble making it out as a man-made object. It would look
>like a "I", not like a point of light. Does the fact that it would
>be a government, rather than a commercial, project mean would not
>be disrupt the pristine sky?

   At least the science of Astronomy would benefit from a scientific
   station in orbit. Also, to be useful for advertising, a sign in
   space would have to be pretty bloody huge, not a "little I" as the
   space station would produce.

   (Not that I totally agree with NASA; I just disagree with Coke more!)

   -Scott
>                                                Frank Crary
>                                                CU Boulder

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


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In article <[e-mail]> [e-mail] (Nick Haines) writes:
>   The _only_ difference between this structure and any other proposed
>   space structure is that this one would contain a commercial message.
>   It might say "Coke" instead of "NASA".

>I have never seen, here or on any other forum, any proposal from NASA
>or any other space agency to place mile-scale objects in very low
>earth orbits.

The truss for the proposed space station, Freedom, would have been
~400 m (if memory serves) long. From its 300 km orbit, that would
have made it easily resolvable by the naked eye. It would look like
a bright "I", not like a point of light.

>...Such objects are in fact _bad_ ideas technically,
>because of the extreme drag they would suffer and the consequent
>orbital decay.

Only if they are long in all dimensions. If they are long and thin,
this is less of a problem.

                                            Frank Crary
                                            CU Boulder

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

End of Space Digest Volume 16 : Issue 614
------------------------------