Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v12_5/v12_552.txt

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Subject: SPACE Digest V12 #552

SPACE Digest                                     Volume 12 : Issue 552

Today's Topics:
               A philosophical question
             Re: LNLL Inflatable Stations
              Re: Space Station mission
       Re: You Can't Expect a Space Station to be Cheap
             ESA Bulletin no. 63
            Re: Soyuz availability
Re: LLNL size and Fred micrograv environment (was LLNL astronaut delivery)

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Date: 12 Nov 90 03:44:38 GMT
From: ingr!infonode![e-mail]  (Rusty Wiginton)
Organization: Intergraph Corp. Huntsville, AL
Subject: A philosophical question
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     I'm interested in your thoughts about the importance of space
     exploration and other NASA activities -- Not so much from a
     scientific or technological standpoint, but from a personal/
     philosophical one. Why, for example, do you feel it is important
     to pursue long-term programs, such as Space Station Freedom or
     say, a manned mission to Mars? Why should  billions of dollars
     be spent on projects that cannot promise success? I know this
     question has been asked before but with current issues leaning
     toward budget constraints and NASA's reliablilty, I'd like to
     see a different point of view.


--
                        .| Rusty Wiginton              .
                        .| uunet!ingr!b17a!rbw!rusty   .
                        .|                             .

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Date: Mon, 12 Nov 90 16:54:49 -0500
From: "Allen W. Sherzer" <[e-mail]>
To: [e-mail]
Subject: Re: LNLL Inflatable Stations
Newsgroups: sci.space
In-Reply-To: <[e-mail]>
References: <[e-mail]> <[e-mail]>
Organization: Evil Geniuses for a Better Tomorrow

In article <[e-mail]>:
>Since LLNL is a large lightweight structure it will be subject to high drag,
>compared with, say Freedom.  This means more reboosting, more propellant

Already included in their budgets. They will use (from memory) 3T a year
of fuel for this. An alternative they are looking at is a 10KW ion engine
which will reduce fuel demand by ~80%.

> (already a problem on Freedom), and higher engine duty cycles. Is there any
> way they can make it smaller ?

An inflatable station could be made smaller for 0G however if they are
to maintain artificial gravity, it is about as small as they can get. It's
not clear which has more life cycle cost. Crew can be left on a spinning
station for a year with no problems.

An inflatable station used as a Freedom replacement could be smaller and
run at 0G if desired.

>There are practical problems with spinning a station.   Need to despin every
>time EVA is needed, expensive on propellant/power.

Nope. The airlock module doesn't rotate.

>Structure must carry centrifugal loads, makes it heavier.

Already calculated (see the ILC Dover report). Stresses are welll within
the strength of the materials used.

>Reboost thrusters must be gimballed,

Or reboost partially whenever the thrusters point the right way. Either
way, this has been considered.

>In practice the station will need a spun section attached to a despun
>section.

As I said, already in there. The airlock is at 0G.

>Crew transfer between the two is tricky.  EVA transfer hazardous.
>And designing a leak-free IVA tunnel with slip rings and airtight bearings is
>at least a few hundred $M.

Already included in the cost. This has been anticipated, designed, and
included in weight as well as cost budgets.

>Plus lots of lost sleep worrying about when the
>thing will seize or rupture, sometime it WILL do one or the other, or both.

If it fails, the access ports closes and locks. There may be a slight drop in
pressure in the central core but that would be it. The two ends of the
station would also be out of contact with each other until it was fixed.

There would be no loss of either sleep or life.

  Allen

--
+---------------------------------------------------------------------------+
|Allen W. Sherzer| I had a guaranteed military sale with ED-209. Renovation |
|   [e-mail]  | programs, spare parts for 25 years. Who cares if it      |
|                | works or not?  - Dick Jones, VP OCP Security Concepts    |

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Date: 11 Nov 90 23:23:43 GMT
From: gandalf.cs.cmu.edu![e-mail]  (Donald Lindsay)
Organization: Carnegie-Mellon University, CS/RI
Subject: Re: Space Station mission
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Charles Radley) writes:

>+ LLNL won't loft the science equipment.
>+This is smart: the alternative is no space station, and then there
>+_really_ won't be any science done.
>
>What is smart about not lanching any science equipment ?
>How can you get science out of a station with no equipment ?

How can you get science out of a cancelled station, or one that
reenters because the Shuttle fleet gets grounded again?

A minimal station can do the following:
- research whether the minimal station works!
    (This includes the proposed power supply, the meteor-
    bumper issue, the artificial gravity, the escape
    system, ...)
    (You're going to tell me Fred won't need any retrofits
    after first occupancy?)
- research human reaction to artificial gravity.
    (The human is the equipment. I don't know how many
    successful launches the configuration takes: 6? Against
    what, 26 for a minimal Fred?)
- provide a place to hang the equipment that is brought up later.
- provide a rallying point for funding battles, with each money
  increment making the station one notch less minimal.

BTW, we need a good colloquial name for the LLNL station. The
Oscar (as in Oscar Meyer)?
--
Don        D.C.Lindsay

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Date: 9 Nov 90 15:43:35 GMT
From: usc!samsung!umich!sharkey!cfctech!teemc!fmeed1![e-mail]  (Russ Cage)
Organization: Ford Motor Co., Electronics Div., Dearborn, MI
Subject: Re: You Can't Expect a Space Station to be Cheap
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
Sender: [e-mail]
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In article <[e-mail]> [e-mail] (Fraering Philip) writes:
>In article <[e-mail]> [e-mail] (Russ Cage) writes:
>RC>Show me anything like SSX which has flown even 2 flights, and
>RC>come within a factor of 2 of its cost target.
>Well, for starters, Max Hunter, SSX's main proponent, says that it is
>less complex than a major airliner.

1.)    Has it flown?  No.
2.)    Has it come within 2x its cost targets?  Unbuilt, so we don't know.

I am still waiting for an example meeting my criteria.  SSX is not
an example, having not bent metal yet, much less having flown.  As
such, it cannot be given as an example of a reusable vehicle which
is cost-competitive with expendables.  IF it meets its design
criteria, it MIGHT, but that has yet to be demonstrated.  Expendables
have much higher certainty in their life-cycle costs (due to the
vagaries of refurbishment being eliminated), so it is much easier
to give firm numbers.
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (CHATTY MAIL NOT ANSWERED HERE)
Home:  [e-mail]  (All non-business mail)
Member:  HASA, "S" division.

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Date: Mon, 12 Nov 90 10:56:36 CET
To: [e-mail]
From: [e-mail]
Comment: CROSSNET mail via MAILER@CMUCCVMA
Comment: File BULL63 TEXT A
Subject: ESA Bulletin no. 63

Subject: ESA Bulletin no. 63 (May 1990)

Here is an overview of the contents of ESA bulletin no. 63.
The issue is labelled as "Ulysses Launch Issue" and contains
mainly articles concerning Ulysses.

The articles are
- Ulysses in the Context of the ESA Scientific Programme
  The article describes ESA's long-term program "Horizon 2000", covering
  the science missions up to the year 2000, and the place of the
  Ulysses mission in this context.
- Ulysses - A Brief History
  The history of the Out-of-Ecliptic/ISPM/Ulysses mission -
  from the two-probe NASA/ESA mission to the one-probe Cooperative
  Mission
- Ulysses - An ESA/NASA Cooperative Programme
  Who contributes what, practical management difficulties across
  the continents
- The Scientific Mission of Ulysses
  Answers to the "Why?"
- The Ulysses Scientific Payload
  Answers to the "How?" (Description of all experiments on board)
- The Ulysses Spacecraft
  Probe design, details on all subsystems
- RTGs - The Powering of Ulysses
  History of RTG use, RTG concept, details on the RTG structure
  and principle
- The Ulysses Launch Campaign
  Timeline of the activities before launch
- Post-Launch Operations and Data Production
  Operations in the Shuttle, in orbit and experiment switch-on.
  Ground segment description.
- Orbit Design and Control for Ulysses
  The swing-by at Jupiter, trajectory optimisation, Attitude and Orbit
  Control system
- Industrial Cooperation on Ulysses
  Who built what?
- The Ulysses Storage and Recertification Activities: The Managerial
  Problems
  How to store a spacecraft and what to do with the people who
  know about it
- The International Heliospheric Study
  The international science cooperation around the Ulysses mission

Other Articles:
- Successful flight for Ariane V37
- New Chairman of the ESA council
- Giotto - the First-ever Controlled Earth Swing-by of an
  Interplanetary Space Probe
- Go-ahead for ERS-2 and POEM-1
  (ERS-2: second satellite of ESA's Earth Observation Satellite
   series. POEM-1: Polar Orbit Earth Observation mission)
- Queen Beatrix of The Netherlands Inaugurates ESTEC Test Centre
  and Opens Noordwijk Space Expo
- ESA's Advanced Telecommunications Programmes Approved
  (Laser-beam optical communications, S-band high-performance multiple
  access payload, L-band mobile payload for satellite links to
  European land vehicles
- MOU on NASA/ESA Cassini Mission
  ESA will build the Huygens Titan probe, NASA builds the Cassini
  Saturn Orbiter (hopefully)
- Meeting between Hungarian Delegation and ESA
- Cosmic Ray Experiment Returned from Space
  (Pictures of LDEF and the Cosmic Ray Experiment from ESA Space
  Science Department and Ireland)
- 15th ESA/Japan Meeting
- First Eurostep Conference (Use of satellites in education and
  training)
- ATSR to fly on ERS-1 (Along-Track Scanning Radiometer, a payload
  to measure sea surface temperatures to a few tenths of a degree
  centigrade)
- Hubble Space Telescope (Nothing new for regular net readers)

That's it.
ESA Bulletin can be obtained free of charge from
ESA Publications Division
ESTEC, Postbus 299
2200 AG Noordwijk
The Netherlands

Regards, Lutz Massonne

 +===================================+===============================+
 | Lutz Massonne                     |This mail expresses my personal|
 | Robert-Bosch Str. 5               |opinions only and is in no way |
 | D-6100 Darmstadt, FRG             |official or reliable.          |
 +===================================+===============================+

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Date: 11 Nov 90 17:48:22 GMT
From: sumax!polari![e-mail]  (Charles Radley)
Organization: Seattle Online Public Unix [phone]
Subject: Re: Soyuz availability
References: <[e-mail]>
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Reference availability of Soyuz.   As I have posted several times.
The Soviets are willing to sell Soyuz, but US State Dept regs prevent private
companies from purchasing it, and US Govt policy prevent its use by govt agencies.

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Date: 13 Nov 90 05:40:34 GMT
From: sumax!polari![e-mail]  (Charles Radley)
Organization: Seattle Online Public Unix [phone]
Subject: Re: LLNL size and Fred micrograv environment (was LLNL astronaut delivery)
References: <[e-mail]>, <[e-mail]>, <[e-mail]>
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+Continuous manned presence *is* a problem for microgravity research.
+So is a shifting CG, which moves the experiments into regions of
+greater or lesser tidal force.
+This is not a benefit, it is a liability.  Ask the micrograv
+researchers.  A free-flyer can be tailored to the job, and
+does not suffer from vibration or CG shifts on the station proper.
-
In an ideal sense this is true.  In practice, experiments fail all
the time, and benefit from human intervention to get them going
again.

+On a free-flyer, thruster pulses can be scheduled to coincide with
+dead time, furnace re-loads, and so forth.
-
It is rather the reverse, the experiments will have to be scheduled
around when the burns are required, which will be once or twice per
orbit.

+It may mean a delay between the time something breaks and the
+time it can be fixed, but if something is broken you don't care
+about giving it a bit of gee, there is no processing to be
+disturbed.
-
What about the non-broken expts ?  Or do you only plan on having
one experiment on the free-flyer ?  if you have multiple experiments,
every failure is a complete loss until human operators return.  The
other experiments will continue.

+On a manned platform, you are going to have vibration any time the
+crew is moving around, which will be much of the time.  There is work
+which cannot be done on a manned platform, and the Fred design
+doesn't allow for it at all.
-
Indeed.   It is a trade off.  NASA considers human presence to be
of benefit, on balance.

---------------------------------------------------------------
+And now for the part I find confusing.  This posting brings an
+apparent contradiction into sharp focus, because it holds both
+parts of it in more detail than ever before in this discussion:
-
I am sorry you are confused, I will attempt to clarify.

+>What commercial needs ? It puzzles me why people such as yourself
+>prefer a small station to a big one.
+Here you are apparently saying that the LLNL+ station would be
+smaller than Fred, but then you say...
-
As a space engineer, by "big" I habitually mean "heavy".   Volume
is of little interest to  practical space engineering.   In fact,
large volume lightweight structres have high drag, so are
undesirable.   Better to have a maximum weight to cross section
ratio.   LLNL is "small" in the sense it has less weight, because
it comprises less hardware with less capability.

+There you admit that LLNL would have more volume than Fred (and
+thus more room for equipment).  Well, which is it?  Or were you
+talking about Fred in #1, and not LLNL?  If so, I'm sure there
+is an answer to your question.
--
If LLNL plans to have more equipment than Freedom, then it must plan
to be heavier than Freedom, which means it needs more launch flights
than freedom.
And if it plans to have more equipment than Freedom, then it will be
more expensive than Freedom too.
  I am rather bored by all this interest in the volume of a station,
there are many problems with Freedom, but

"NASA Scientists Admit Serious Volume Problem on Freedom"

is not a headline I recall seeing anywhere.  LLNL would seem to be
spending a lot of effort solving the wrong problem.

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End of SPACE Digest V12 #552
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