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Subject: SPACE Digest V11 #72

SPACE Digest                                      Volume 11 : Issue 72

Today's Topics:
       Re: Fun Space Fact #1: Launcher Development Costs (long)
       Re: Fun Space Fact #1: Launcher Development Costs (long)
            Re: Galileo Update - 02/16/90
            Re: Galileo Update - 02/16/90
              Re: Giotto is back
     ROSAT spacecraft arrives at Florida launch site (Forwarded)
----------------------------------------------------------------------

Date: Thu, 22 Feb 90 13:59:53 CST
From: [e-mail]
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

[Hmmm, I seem to have this problem with you requiring very lengthy
responses, Henry.]

>> "uunet!attcan!utzoo!henry [e-mail] (Henry Spencer) "

>> The USAF's demands for a bigger orbiter with more cross range
>> increased the size of the bird considerably but didn't affect
>> complexity much.

A much bigger and more capable bird (at least in theory) built at
the same degree of sophistication would seem to me to indicate a
much more 'complex' vehicle, with a commensurate increase in
processing time between flights.  After all, NASA couldn't just make
all the parts bigger.

And even if it were possible to just scale up everything (which I've
been assured is almost never the case), you're still greatly
increasing the stresses on the parts, and it would still require
much more processing.

>> a smaller shuttle might have had smaller engines, but I see
>> no reason to believe they would have been any less troublesome.  And
>> again, I don't see how the smaller size would have reduced complexity
>> significantly.

I believe I saw someone (I think it was on this list - the poster
escapes me at the moment, but I can probably find it if necessary)
mention something about it being much easier to design, build, and
maintain smaller liquid hydrogen engines than it was larger ones,
which was why one usually saw hydrogen fueled stages appear as the
smaller upper stages of boosters first.

So even 'pushing' the technology, I think a smaller engine would
have required less servicing than the current one.

I'm not sure that we're talking about the same thing when we're
using the word 'complexity' here.  A larger bird generally has more
parts, not just the same number of parts built on a bigger scale
(all else being equal).  Hence the larger bird is 'more complex'.

I get the feeling from the sense of your notes that you're referring
to something slightly different; what I would call 'level of
technology' or 'level of sophistication'.

>> It would at least have had liquid-fuel boosters.

As far as I'm concerned, putting men up on anything that you can't
shut down and get the hell away from when it goes sour is a bad
design decision.  Something that should have been better taken into
account by NASA (not to mention them not listening to the experts
from the organization with more solid-motor experience than anyone
else in the world - the USAF - when they took this decision and made
their predictions).

>> I'm not really convinced that the turnaround situation would have
>> been much better, though.

I guess we're just going to have to disagree on this one.  Seems to
me that servicing a smaller vehicle with fewer parts taking less
stress would reduce it significantly.  But the only way to PROVE
anything is to build one - and I can't see them giving us the money
to do that.

>> My original statement still stands -- NASA could not have met
>> schedule or cost promises even with ample funding -- because those
>> promises have been scaled back again and again to "match" the available
>> funding, and NASA hasn't been able to meet them, ever.  The problem is
>> fundamental, not an accident of a funding shortage at a particular time.

Welcome to the 'real world' of cost estimating, budget and schedule
projection, and marketing.  If the budgetary process was set up so
that people could give realistic estimates and get the money they
need to meet them without having things micro-managed by folks who
don't understand or care about what is involved and who want to
nickel and dime a project to death, perhaps this wouldn't be the
normal pattern.

But it is.  And you don't change it by just 'bashing' on the people
who do it.  In fact, that just tends to make it worse.  I still
maintain that insofar as anything purchased by a bureaucracy ever
does, the original Shuttle would have met its targets if given
adequate funding.

[I think we're talking from two different perspectives again.]

>> The space station is repeating the same pattern.

I disagree.  The space station is following a much *worse* pattern,
although the general overall trends are perhaps similar.

>> >Well, until such time as you'd care to postulate many hundreds of
>> >launches of these light boosters per day, I think I can probably
>> >safely stand by my statement.

>> "Many hundreds"?  Where do you get "many hundreds"?  It doesn't take
>> that many 2000-pound launches to equal the entire capacity of the
>> current shuttle fleet (which is, optimistically, ten 40000-pound
>> launches per year).  That's about a launch a day, which is not that
>> far from what the Soviets can do now if pushed.

And nine women can produce a baby in a single month if one woman can
do it in nine.

This is something I continually have to explain to people around
here.  If something is scheduled to take 9 man-months when worked on
by an individual, you can't finish it in a month by throwing 9
people at it.  Neither can you replace the payloads of 10 40,000
pound launches with 200 launches of 2,000 pound payloads, unless
your sole yardstick is the amount of mass in orbit rather than how
it's organized once it gets there.

>> I dimly recall a design sketch from Jordin Kare's group for a laser
>> launcher costing about half a billion dollars that could launch more
>> than the entire shuttle fleet, for that matter.

Great!  Let's build it!

[I trust the estimates of cost and capability you give aren't the
'standard' sort of estimates, so it won't wind up costing $1 billion
and launching half as much.]

>> >Over the long term, putting things together is undoubtedly cheaper
>> >than building them in one piece down here and then having to loft
>> >them in one piece.  But it assumes having someone at the other end to
>> >do the assembling.  And in order for costs to remain cheap when
>> >including *that* cost, it's necessary to postulate some way for
>> >those folks (or machines) doing that assembling to remain on
>> >station.  And so on.

>> Um, why is that such a fundamental difficulty?  Or are you pricing that
>> based on the Incredible Gold-Plated Space Station?

Not hardly.

>> It takes *one* of those 2000-pound launches to add a human to the
>> collection of payloads comprising a mission.

And how long is your man-in-a-can's life support good for?  Keep in
mind that it takes over an hour for a cosmonaut on Mir to go outside
and just kick a connector loose when you think about assembly times.

>> Be generous and add one more for a little tug to bring the pieces
>> together (there are tug designs a lot smaller than 2000 pounds).

Maybe you'd better be a little more generous, and add more than one
human and more than one tug, along with rather more extended
life-support and some fuel to chase the pieces with.  Keep in mind
that humans actually working in zero-g use a lot of oxygen.

>> For a payload the size of a shuttle load -- 40000 pounds,
>> 20 launches -- that's a 10% overhead.  That seems bearable.

Now add enough propellent and life-support for your single man to
chase down 20 pieces and push them all together, fasten them, etc.
He's going to be on orbit for a while.

One can try for computer guided rendesvous and self-assembly, but
then each of your pieces needs its own fuel supply, plus parasitic
weight for the brain and the control system it runs.

Also keep in mind that that 2,000 pound payload is the *biggest*
booster you have.  Most will be smaller coming from the program that
we started this discussion with.  I'm assuming a normal distribution
of payloads between several hundred and several thousand pounds for
your various vehicles.

Or is the proposal to spend that $30 billion that Mr. Bowery
proposed to get a single 2,000 pound payload booster?  This hardly
sounds like economy to me.

>> Yes, it would be better to have an orbital base for such things.  That
>> can be on the level of Mir, however, and need not cost even as much as
>> Mir, never mind Expensivedom er excuse me I meant Freedom.

Personally, I think I like the idea proposed by JPL.  But I think
you'd be hard pressed to put that up in little bitty chunks, too.

>> If Amroc had been working twenty years ago, the only real problem I
>> can see them having that they don't have today is somewhat heavier
>> engine casings.  The other materials and electronics issues are
>> second-order effects.

When your total payload is only a few hundred or a few thousand
pounds, things like "somewhat heavier engine casings", or even those
"second-order effects" don't take long to eat up enough of your
payload for your booster to be worthless.

>> >No, they're not doing anything that couldn't have been done, but
>> >they're able to do it more easily and more cheaply...

>> Not that much more easily and more cheaply.  They'd have needed more
>> money to do it ten years ago, but not whole bunches more.

Well, I think it depends on what you call 'bunches'.  They'd have
been pushing the materials technology (among others) to get what
they've got now, and as you said, pushing the technology is a good
way to spend billions.

I remember when the 'conventional wisdom' was that it took at least
3 stages to get a reasonable payload to orbit.  And I'm not that
old.  Yes, one can put up useful payloads with 1950's technology.
But that's not what we're talking about here.


==============================================================================
| Fred McCall  ([e-mail]) | My boss doesn't agree with anything  |
| Military Computer Systems           | I say, so I don't think the company  |
| Defense Systems & Electronics Group | does, either.  That must mean I'm    |
| Texas Instruments, Inc.             | stuck with any opinions stated here. |
==============================================================================

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

Date: 22 Feb 90 16:44:27 GMT
From: sun-barr!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] (SERRE GLENN) writes:
>>  I hope that we will soon have some light launch capability outside of
>>NASA, I just wish I could believe that we will have a heavy lauch
>>capability.
>
>So what are Titan IV and Commercial Titan, chopped liver? ...

Medium launchers.  "Heavy" means Saturn V / Energia class.  (We won't even
mention the 8-booster variant of Energia...)  Shuttle-C might be acceptable
in a pinch.

Remember also that the Titan launch rate is pitiful.  NASA launched Saturns
at a higher rate than that...  (It helped that the Saturn launch facilities
were designed for high launch rates.)
--
"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: 22 Feb 90 22:29:14 GMT
From: polyslo!vlsi3b15!vax1.cc.lehigh.edu!netnews.upenn.edu!eniac.seas.upenn.edu![e-mail]  (Daniel P. Barron)
Subject: Re: Galileo Update - 02/16/90

In article <[e-mail]> [e-mail] writes:
>In article <[e-mail]>, [e-mail] (Douglas Otto) writes:
>> This is odd since 3.6hr * 3600 sec/hr * 256 bits/sec = 3317760 bits =
>> 3 x 1105920 bits per image!  This is a "bit" larger than 3 x 106 bits.
>> Don't these PR people check what they write?

>Would it make more sense if 3x106 was written as
>              6
>    3 x 10

I think the usual (and simpler) convention is 3E6 or 3x10^6.

db


_______________________________Daniel Barron__________________________________
 "All I ask                          | E-mail: [e-mail]
    is a chance to prove             |         [e-mail]
      that money                     |         [e-mail]
        can't make me happy."        | USMail: Suite 1400, 3620 Locust Walk
_____________________________________|_________Philadelphia, PA  19104________

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

Date: 22 Feb 90 19:07:02 GMT
From: snorkelwacker!usc!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!sp20.csrd.uiuc.edu![e-mail]  (James R. B. Davies)
Subject: Re: Galileo Update - 02/16/90

In article <[e-mail]>, [e-mail] (Douglas Otto) writes:
> This is odd since 3.6hr * 3600 sec/hr * 256 bits/sec = 3317760 bits =
> 3 x 1105920 bits per image!  This is a "bit" larger than 3 x 106 bits.
> Don't these PR people check what they write?

Would it make more sense if 3x106 was written as
              6
    3 x 10
?

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

Date: 22 Feb 90 00:15:09 GMT
From: elroy.jpl.nasa.gov!usc!cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Giotto is back

In article <[e-mail]> [e-mail] (S. Khai Mong) writes:
>>   The Giotto spacecraft had been put into "hibernation" shortly after
>>   the Halley encounter. This means the spacecraft is in a attitude with its
>>   spin axis perpendicular to the obital plane.
>
>Why is that the most logical attitude when it is put into hibernation?

It guarantees that the solar panels (which form a cylinder around the
spin axis) are always getting full sunlight.
--
"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: 21 Feb 90 17:10:21 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: ROSAT spacecraft arrives at Florida launch site (Forwarded)

Vera Hirschberg
Headquarters, Washington, D.C.                  February 20, 1990

George H. Diller
Kennedy Space Center, Fla.


RELEASE:  90-27

ROSAT SPACECRAFT ARRIVES AT FLORIDA LAUNCH SITE


     The ROSAT spacecraft, a German scientific satellite to be
launched by NASA in early summer, arrived today at Cape Canaveral
Air Force Station, Fla., after a flight from the Federal Republic
of Germany (FRG) aboard a German 747 cargo plane.

     ROSAT, which stands for Roentgen Satellite, will be launched
using a Delta II rocket in late May or early June.  Built by
Dornier Systems of the FRG, ROSAT will perform the first all-sky
survey with an imaging x-ray telescope.  The survey will be
followed by individual observations of x-ray sources.  ROSAT is a
cooperative project between NASA and the FRG's Federal Ministry
for Research and Technology.  The United Kingdom is cooperating
on ROSAT through an agreement with the FRG.

     The spacecraft is equipped with two imaging telescopes - a
German Large X-Ray Telescope and a smaller extreme ultraviolet
telescope known as the Wide Field Camera, contributed by the
United Kingdom.  A High Resolution Imager (HRI) on the Large X-
Ray Telescope, was contributed by the United States.  The HRI was
built by the Smithsonian Astrophysical Observatory and is managed
by NASA's Goddard Space Flight Center, Greenbelt, Md.

     After the initial 6-month all-sky survey, ROSAT will be
devoted to detailed observations of x-ray sources with observing
time divided among investigators from the United States, the FRG
and the United Kingdom.

     The 5,000-pound satellite will be deployed into a 53-degree
inclined, circular orbit 360 miles from Earth.  ROSAT will be
launched from Complex 17 at Cape Canaveral Air Force Station by
the U.S. Air Force and a McDonnell Douglas launch team.

     Final assembly and pre-launch testing of ROSAT's science
instruments will be performed in the clean room at NASA's Hangar
AE, Cape Canaveral Air Force Station.

     Within NASA, the ROSAT program is managed by the
Astrophysics Division of the Office of Space Science and
Applications.  NASA's Goddard Space Flight Center is responsible
for detailed implementation of the ROSAT program.

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

End of SPACE Digest V11 #72
*******************