Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V16_0/V16NO003.ZIP/V16NO003

Internet Message Format | 1993-07-13 | 34KB

Date: Wed,  6 Jan 93 05:11:21
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #003
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed,  6 Jan 93       Volume 16 : Issue 003

Today's Topics:
                       *** BUSSARD RAMSCOOP ***
                 Aerospike Engines... what are they?
                  ASTM, Saturn and MOL (Was Re: MOL)
                           DCX tech. info?
                Fabrication (was fast track failures)
                         fast-track failures
     foreign partnerships was(Re: How many flights are Orbiters)
             Genetically Engineered Microbes in Real Use?
                          Moon Dust For Sale
      Question:How Long Until Privately Funded Space Colonizati
     Question:How Long Until Privately Funded Space Colonization
                         satellite costs etc.
  Shuttle a research tool (was: Re: Let's be more specific) (3 msgs)
   Stupid Shut Cost arguements (was Re: Terminal Velocity (2 msgs)

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

Date: 5 Jan 93 20:12:25 GMT
From: nathan wallace <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

i lied.

well, sorta. The *correct* name of the book from my earlier posting is
"The Starflight Handbook", by Eugene Mallove and Gregory Matloff.
Its ISBN number is 0-471-61912-4. *sigh* memory is the first to go...

Chapter 7 is the one which deals with the Bussard Ramjet. It details not

only the Bussard design, but two variants which are more feasable using
current technology and theory. The difficulties with p-p fusion as noted
in the net discussion are mentioned; one of the variants addresses this
problem. The net analysis by the authors is that ramscoops are probably
limited to .2 c and not the most cost effective way to get around the
near stars. They add the caveat that this is in terms of *current*
technology; a breakthrough in any of a half-dozen fields might change
the picture enormously.

The book also considers several other interstellar flight systems. It
has very good coverage of the Daedalus probe designed by the British
Interplanetary Society back in the 70's and project Orion.

Happy 1993!

+----------------------------------------------+------------------------+
|                                              |              __        |
|                                              |             / /\       |
|  Nathan F. Wallace                           |      ______/ /_/___    |
|  email: [e-mail]  |     / ____  ______ \   |
+----------------------------------------------+    / /\__/ /\____|\/|  |
|                                              |   | |\/ / / /     \|/  |
|  Disclaimer: My opinions are my own, and are |   | || / /_/_____      |
|              not those of any other person,  |   | ||/_______  /\     |
|              organization, or supreme being. |   | ||\______/ / /     |
|                                              |   | ||      / / /      |
+----------------------------------------------+    \ \_____/ /_/__/\   |
|  "War is the art of deception."              |     \_____  _______/|  |
|                                 Sun Tzu      |      \___/ /\______|/  |
|                                              |          \_\/          |
|                                              |                        |
+----------------------------------------------+------------------------+

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

Date: 5 Jan 93 15:37:00 PST
From: "RWTMS2::MUNIZB" <[e-mail]>
Subject: Aerospike Engines... what are they?

On Date: Mon, 4 Jan 1993 13:44:26 GMT, "Herity D." <[e-mail]>
writes :
>As I understand it, the exhaust is confined between the spike and the
>external airflow. So how can it work in a vacuum ? Can it ?

The exhaust plume boundary expands as the ambient pressure decreases in
*both* bell and aerospike nozzles (this can be seen very well during
night launches).  High performance over most of a rockets' operational
profile (low pressures and in a vacuum) is achieved by having a high
exit/throat area ratio which allows large plume expansion.  Doing this
with a bell nozzle can result in flow separation at the walls of the
nozzle near the exit when operating at low altitudes (launch), which
leads to loss of performance and possible structural failure of the
nozzle due to dynamic loads [flow separation is responsible for the large
nozzle motion on the SSMEs during startup - watch closely next launch if
you can get NASA Select].  Therefore a compromise altitude must be used
for the design point of a bell nozzle.

The advantage of an aerospike is that it can achieve the desired high
exit/throat area ratio at high altitude while still being efficient at
lower altitudes due to the automatic compensation.

As I noted earlier, an excellent basic description of nozzle design at
aerospike engines can be found in Rocketdyne's "Threshold" magazine,
Number 8, Spring 1992. (write to Rocketdyne Division/Rockwell
International, 6633 Canoga Avenue, Mail Code AB57, Canoga Park, CA, USA,
91304 or call [phone] to get a copy).

Disclaimer: Opinions stated are solely my own (unless I change my mind).
Ben Muniz, Rocketdyne, SSF Dynamics | "Man will not fly for fifty years"
[e-mail]    |     Wilbur to Orville Wright, 1901

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

Date: Tue, 5 Jan 1993 18:04:21 GMT
From: Gary Hughes - VMS Development <[e-mail]>
Subject: ASTM, Saturn and MOL (Was Re: MOL)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Brian Stuart Thorn) writes...
>   Thanks for all that info, my copy of 'Stages to Saturn' is in a box
>   stored away somewhere. But wasn't this discussion REALLY about
>   whether Centaur actually flew on a Saturn? Not was it intended to,
>   but did it ever go up on one? It didn't, to the best of my knowledge.

No live S-V stage ever flew. Indeed, the Block 1 Saturns and the first Block 2
Saturn used boilerplate Jupiter tanks and nose cones to simulate the S-V. One
reference suggests that Von Braun pushed to cancel the S-V, to maintain the
image that the Saturn 1 was an R&D vehicle (thus ensuring funds for future
Saturn development).

FWIW, I did some more digging over the holiday and found that an earlier
proposal had the S-V powered by two LR-119 engines (aka RL-10B in at least one
source) before the LR-119 was canned.

Does anyone know if 'Stages to Saturn' is still purchaseable?

gary

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

Date: Tue, 5 Jan 1993 21:06:21 GMT
From: Henry Spencer <[e-mail]>
Subject: DCX tech. info?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>How can you have dynamic pressure when you're hovering???

"Hover" is being used loosely here; the later tests will involve noticeable
(although subsonic) velocities.

>Also, will these flights be pre-programmed onboard, or will they be
>controlled from the ground?

As I recall, they're preprogrammed with the ability to override from
the ground.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 5 Jan 93 21:29:35 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Fabrication (was fast track failures)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas Clarke) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman)
>writes:
>> In article <[e-mail]> [e-mail] (Edward
>V. Wright) writes:
>> >
>> Most engineering *is* paperwork, or workstation work today. Otherwise
>> it's just tinkering on a wing and a prayer. You have to bend metal to
>> *test* your engineering, but bending metal *isn't* engineering. It's
>> fabrication done by tradesmen.
>
>I can't let this go by.  This is a common attitude in America.  It
>leads to low pay for production engineers and inefficient production
>methods etc. etc.  Result is the current economic morass with most
>production going overseas.
>
>I think engineering must consider how something is to be made.  The
>most elegant design is useless if it can't be manufactured.
>Knowledge of what can be made is obtained by bending metal, or
>at least by interacting with those who do.

I'm not disparaging skilled tradesmen, in fact I usually hold them
in higher regard than most engineers. Engineers would benefit by
*listening* to them more often. But hammering metal is a skilled
trade, not engineering. Good engineers take production requirements
into account in their designs, bad ones don't. Production engineers
do time and motion, setup optimized assembly lines, and natter about
workgroups and just in time subassembly deliveries. Those are important
in some mass production facilities, but good design engineers make or
break production at the very beginning of the development cycle. Ease
of assembly and ease of field service have to be designed in from the
very beginning of a product. Having design engineers apprentice on
the shop floor for a few years *before* they get to design a product
would do a world of good for our manufacturing sector. It certainly
has for the Japanese and old school Germans.

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     |                     | emory!ke4zv![e-mail]

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

Date: Tue, 5 Jan 1993 19:33:50 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: fast-track failures
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Shari L Brooks) writes:


>In article <[e-mail]>
>[e-mail] (Brad Whitehurst) writes:

>>In article <[e-mail]> [e-mail] (Edward
>>V. Wright) writes:

>>>You think a typical engineer earns $100,000 a year?
>>>
>>>I want to work for your company!

>>    By the time you also pay for FICA, pension, benefits, and
>>overhead, a $50,000 engineer can easily cost a company double his base
>>pay!  BTW, Ed, I ALSO help do the budgeting for my lab, so before you
>>ask, yes, I have some experience in this!

>Wow, your lab pays for FICA?  I'm impressed.  It takes up about a third
>of *my* salary, when combined with income taxes.  Right out of my pay.
>I was under the impression it came out of everyone's pay, that that was
>the idea behind "Social Security".

I think you need to find out a bit more about manpower accounting and
just who pays what, Shari.  The first thing you will find is that your
employer pays the same amount of FICA that you do -- in other words,
you only pay for half of it.  Then there are things like health
insurance (typically in the $4k range), pension contributions (figure
about the same as your FICA bill, at least), usage of facilities, etc.
Having a single engineer is likely to cost you MORE than $100k, by the
time you add in all the overhead costs.

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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

Date: 5 Jan 93 21:11:29 GMT
From: Gary Coffman <ke4zv!gary>
Subject: foreign partnerships was(Re: How many flights are Orbiters)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>
>>DC could be available long before then *IF* we can get DoD to fund the
>>proof of concept vehicle.
>
>If we can get *someone* to fund the proof-of-concept vehicle.  DoD
>may still have the deepest pockets around, but I certainly hope
>McDAC is looking at other sources also.  Perhaps the Japanese
>would be interested in a joint partnership.  It's too bad the
>Delta Clipper wasn't started several years ago when McDonnell Douglas
>was healthy enough to finance such a project itself.

Interesting street rumor reported on the business report of NBC Sunrise
program this morning. Apparently, Boeing is negotiating a partnership
with a Japanese and a German firm to underwrite the development of the
next generation widebody airliner, reportedly seats 600. The report
indicated that even Boeing isn't healthy enough to risk going it alone
on that one, and the US airlines are too strapped to place speculative
orders. If Boeing can't fund a new widebody, MacDD is in deep doo
with DC without a deep pocketed partner to back them. With Clinton/Gore
in charge, DOD is going to be too busy doing environmental cleanups of
the bases they're going to be closing to fund DC, and all those DOD
people and contractor people laid off in the cutbacks are going to be
busy learning which end of a shovel to hold while building Clinton's
road and bridge projects, or training to be medical orderlies in his
national health care program. Maybe MacDD should give the Sultan of Brunei
a call.

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     |                     | emory!ke4zv![e-mail]

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

Date: 5 Jan 93 20:52:54 GMT
From: nathan wallace <[e-mail]>
Subject: Genetically Engineered Microbes in Real Use?
Newsgroups: sci.space

I recall hearing on Chicken Noodle News that a bacterium (*Chlostridium*
I suspect, they'll eat virtually anything, including those buried polystyrene
bottles which were supposed to last ten thousand years and instead lasted
five or so...) has been developed to help in some types of oil spills and
was successfully used in a spill near Galveston a few years ago. Anyone
know more about this?

ps. *Chlostridium* are anaerobic soil bacteria, for which we should all be
**very** thankful, I suspect.

+----------------------------------------------+------------------------+
|                                              |              __        |
|                                              |             / /\       |
|  Nathan F. Wallace                           |      ______/ /_/___    |
|  email: [e-mail]  |     / ____  ______ \   |
+----------------------------------------------+    / /\__/ /\____|\/|  |
|                                              |   | |\/ / / /     \|/  |
|  Disclaimer: My opinions are my own, and are |   | || / /_/_____      |
|              not those of any other person,  |   | ||/_______  /\     |
|              organization, or supreme being. |   | ||\______/ / /     |
|                                              |   | ||      / / /      |
+----------------------------------------------+    \ \_____/ /_/__/\   |
|  "War is the art of deception."              |     \_____  _______/|  |
|                                 Sun Tzu      |      \___/ /\______|/  |
|                                              |          \_\/          |
|                                              |                        |
+----------------------------------------------+------------------------+

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

Date: Tue, 5 Jan 1993 21:12:31 GMT
From: "Thomas E. Smith [LORAL]" <gothamcity!tes>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

I'm just guessing on my figures, but wasn't 500 lbs of moon rock and dust
brought back from the moon? And didn't the entire Moon program cost around
$67 billion? I think that puts the moon dust/rocks at about $134,000,000 a
pound! But as Ken says, it ain't fer sale by Nasa.

                                                       Tom Smith

--
____________________________________________________________________________
|                                      | Tom E. Smith                      |
| It's not my damn planet Monkey Boy!  |                                   |
|                                      | [e-mail]       |

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

Date: Tue, 5 Jan 1993 19:13:12 +0000
From: Chris Marriott <[e-mail]>
Subject: Question:How Long Until Privately Funded Space Colonizati
Newsgroups: sci.space

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

>
>What are the current estimates of folks in this newsgroup of how long it
>will be until the world starts to see privately funded space colonization?
>
>I've noticed that there are some _extremely_ capital intensive schemes around
>which might make the marginal cost of launching mass to orbit fairly cheap.
>(I'm thinking of mechanisms like Clarke's space "elevator" or Bull's
>gun). I'm more interested in technologies like the Henson Sling or SSTO
>technology that might be more useful to private citizens and less likely to
>be shelved or monopolized by governments or mega-corps.
>
>
>Thanks!
>

The "space elevator" - basically dropping a cable from a geosynchronous
satellite to Earth (and, of course, another one upwards so the centre of
mass stays still) is probably the most *lethal* device one might conceive
of building!  Imagine the cable breaks near the mid-point.  You have 38000km
of cable falling to earth at *orbital* velocities, enough to wrap itself
around the entire equator of the planet!  Go figure out the kinetic energy
involved.  How much ocean would it vaporize?  Massive medium-term climatic
changes at best - "nuclear winter" scenarios.  A new Ice Age a distinct
possibility.

These things are not good.
--
--------------------------------------------------------------------------
| Chris Marriott                           | [e-mail]    |
| Warrington, UK                           | BIX: cmarriott              |
| (Still awaiting inspiration              | CIX: cmarriott              |
|  for a witty .sig .... )                 | CompuServe: 100113,1140     |
--------------------------------------------------------------------------


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

Date: Tue, 5 Jan 1993 21:13:34 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Question:How Long Until Privately Funded Space Colonization
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Randy Burns) writes:

>What are the current estimates of folks in this newsgroup of how long it
>will be until the world starts to see privately funded space colonization?

Short answer: Soon after the we see privately financed space
industrialization.  Some opinions to the contrary, industry
is not going to spend billions of dollars on space colonies
until there's something for people to *do* there.

And no, a few communications satellites don't count.  To
reiterate, industry is not going to spend billions of dollars
on space colonies until there's something for *people* to do
there.

This assumes you mean a for-profit venture.  It's possible
that a charitable organization such as the National Geographic
Society might foot the bill for a colony before industry has a
need for it, but the cost of such a venture would be formidable.

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

Date: 5 Jan 93 20:05:56 GMT
From: Gary Coffman <ke4zv!gary>
Subject: satellite costs etc.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>Redundancy is always desirable if it's affordable, but there is a practical
>>difficulty with having *cold* spares in orbit. Will they work when we need
>>them?
>
>A cold spare is unlikely to be completely cold.  More likely it will
>operated in a low-power mode so that you can still run diagnostics
>and self-tests on the hardware.
>
>>They have to be cold spares if they share the same orbital slot and
>>frequencies.
>
>Not true.  You can put two birds in the same slot but only use
>half the transponders on each one.  If the transponder frequency
>X transponder fails on bird one, you switch to the frequency X
>transponder on bird two.  If bird one fails entirely, bird two
>can take over the entire service til a new backup is launched.

That might work, but you'd have to swap transponder *pairs* over
from one bird to another due to frequency reuse on opposite
polarizations. Trying to keep two independent satellites perfectly
crosspolarized would be quite a strain on stationkeeping. The
transponders also have their local oscillators phaselocked together
and that would be tougher with two separate birds.

I think the worst problem though isn't really technical. That's
the waste of 50% of each satellite's capacity while it's still
fresh. The longer the birds remain in orbit, the more radiation
damage their solid state electronics accumulate, the more degradation
in output of the solar cell arrays, the more aging on the batteries,
and the more stationkeeping fuel expended. Keeping the spare in another
slot allows all of each satellite's capacity to be used from the
beginning, with secondary services subject to being "bumped" should
a primary service fail.

That's the way NBC is using K2 now. The primary feeds (east and west
coast) are on K2-1 and K2-9 respectively. Less critical news feeds
are on K2-7 and K2-13. They can reconfigure the prime network to the
alternates without repositioning the Earth stations by a single software
command transmitted to the Earth stations. If the bird fails in a way
that loses all transponders, they have bumping rights on SBS 3 and
Westar IV. That requires repositioning of all the Earth station antennas
though. About half the network has secondary antennas at the Earth
stations that are normally kept pointing at one of the backup birds,
though they can be individually pulled off to other targets as need
arises.

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     |                     | emory!ke4zv![e-mail]

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

Date: 5 Jan 93 21:12:53 GMT
From: Francois Yergeau <[e-mail]>
Subject: Shuttle a research tool (was: Re: Let's be more specific)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Francois Yergeau) writes:
>>Ditto, mutatis mutandis.  Likewise, when NASA flies Spacelab, TSS or a
>>TDRS on the shuttle, the latter is used to support NASA's research
>>activities, pursuant to its charter.
>
>So, if your lab bought its own Airbus, hired its own flight crew,
>sold flights to paying customer,
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

It is my understanding that since the post-Challenger return to flight,
NASA has been forbidden to fly commercial stuff on the shuttle. Am I
wrong?

>constructed its own communications facilities and rented those to
>commercial customers,
 ^^^^^^^^^^^^^^^^^^^^

Is NASA doing that?  On any scale bigger than small, occasional excess
capacity?  If so, I agree it's playing games with its charter.

>all of that would be research and development?

As for NASA hiring its own flight crew, constructing its own
communications facilities and in general operating the shuttle system
on its own instead of contracting out the whole works, I don't see any
inherent problem with that.  Just like I don't hire Tektronix to
operate my oscilloscope in the lab.  Of course, it might prove
advantageous, dollar-wise, for NASA to contract out shuttle operations,
but that's another story.

>>It is my understanding that this thread originated when someone
>>claimed that NASA was not respecting its charter by operating the
>>shuttle, which is admittedly not an experimental craft anymore.  I
>>disagree, as long as the shuttle manifest contains only genuine R&D.
>
>Which hasn't been the case for many years now.

Well that was not my impression, but if you wish to post specifics,
I'll stand corrected.  BTW, I assume we're talking about the
post-Challenger era.  Before that, it's clear that the shuttle manifest
contained a lot of commercial stuff, and that this led to the current
ban on commercial operations.

Since we're discussing NASA's charter, would it be possible for some
kind soul to post pieces of it?  I think it would be interesting to
know just how much elbow room NASA has in carrying out its main R&D
mission.

--
Francois Yergeau ([e-mail]) |  De gustibus et coloribus
Centre d'Optique, Photonique et Laser    |  non disputandum
Departement de Physique                  |          -proverbe scolastique
Universite Laval, Ste-Foy, QC, Canada    |

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

Date: 5 Jan 93 20:53:15 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Shuttle a research tool (was: Re: Let's be more specific)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Francois Yergeau) writes:
>
>>The shuttle system itself may not be considered R&D anymore, but it's
>>the manifest that tells you whether it's doing research  or mere
>>"operations."
>
>No, the Shuttle is always doing operations unless it is Shuttle
>itself which is being experimented on. When Shuttle carries spacelab,
>it is engaged in operations *IN SUPPORT OF RESEARCH* but not research.

Under that definition, spacelab is also operations, the gloveboxes and
cameras on spacelab are operations, etc. Looked at differently, spacelab
is a research *tool* purpose built to do research, and it can only do
that with support from Shuttle which was built to carry things like
spacelab.

>When somebody flies a roll during re-entry to see what happens, that
>is research.

Well that would be *aeronautical* research, but that isn't the only
kind of research being done with Shuttle. Shuttle itself is a long
term testbed for reusable flight. It's already yielded valuable
information on the problems and benefits of reusability in manned
spacecraft. Purportedly, the DC program benefits from that knowledge.
The continuing Shuttle improvement programs are development efforts.
So R&D is ongoing with Shuttle. It would be very expensive R&D of course,
if you were to count all of Shuttle's costs as R&D, but it's the only
reusable manned testbed that is flying *today*.  And, in the course of
that flight R&D, other research programs like those on spacelab get
supported at no extra cost. Or the cost gets split among all the
Shuttle payloads, however you want to look at it. There are no ready
flying alternatives to many of the Shuttle missions today, so you
either fly Shuttle or declare a hiatus in manned space until something
new is developed and tested. We went through that once before after Apollo.
Many people think we should have kept plugging along with Saturn, Skylab,
etc until Shuttle proved itself better, or if it was unable to show itself
better, until an entirely different approach was developed and tested.
But we didn't, and manned space efforts suffered as a result. We shouldn't
make that mistake twice.

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     |                     | emory!ke4zv![e-mail]

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

Date: 5 Jan 93 22:16:51 GMT
From: Henry Spencer <[e-mail]>
Subject: Shuttle a research tool (was: Re: Let's be more specific)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Francois Yergeau) writes:
>It is my understanding that since the post-Challenger return to flight,
>NASA has been forbidden to fly commercial stuff on the shuttle. Am I
>wrong?

Partly.  They're forbidden to compete with commercial launch suppliers,
which shifted a lot of comsats and the like off the shuttle.  However,
there was a long list of exceptions, and also quite a bit of stuff that
was deemed shuttle-unique for one reason or another.  They still do a
fair bit of commercial business.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 5 Jan 93 20:32:24 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Allen W. Sherzer) writes:

>We could fly Soyuz on an Atlas or Titan.

Why?  If we're buying Soyuz spacecraft from the Russians,
it would make a lot more sense to buy the boosters also
and skip the integration problem.

>We could build a small station with room and power equal to Shuttle. We
>could dock the two and get far more work done for far less money.

Who is "we?"  If you mean NASA, I don't think so.  A space station
like you're talking about would be more of a construction project
than an R&D project.  NASA isn't set up to handle those.

(On the other hand, I don't think you need to limit your thinking
to small space stations.  If you're working with the Russians, why
not put an Energia third stage into orbit?  Convert it into a "wet"
lab, and you've got a habitable volume bigger than Freedom.)


>We don't use Russian rockets; we use Atlas or Titan. Both routinely rebuild
>their launchers to conform to payload interface requirements and NASA's
>evaluation of Soyuz as ACRV indicate that using Soyuz with US aerospace
>standards isn't a problem.

However, we haven't man-rated the Atlas or Titan since the 60's.
The current assembly lines for those vehicles are pretty much
booked already. You could expand them, of course, but the lead
time for a man-rated Atlas or Titan would be several years.

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

Date: Tue, 5 Jan 1993 21:29:05 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

In <[e-mail]> [e-mail] (John McCarthy) writes:

>The reason Shuttle costs are so much more than projected is that the
>Shuttle requires this army to maintain it between flights.  Hydrogen
>isn't much more expensive than expected, and I doubt the solid fuel
>is either.  When the Shuttle was first proposed, the idea of operating
>it like an airline was part of the plan from the beginning.  It
>turned out that the Shuttle operated too close to the limits of the
>materials and structures of which it was made.  That's why it needs
>so much maintenance.

Well, actually, it's even worse than that.  The original design
concept for the Shuttle system was totally different.  It was
projected to initially cost more and have much lower maintenance
costs.  Due to Congressional budget cutting and all the various
political wars, the design eventually decided on was one which was
cheaper to get the vehicles but which was known to have significantly
higher maintenance requirements and operating costs.  Let's put the
blame for this one where it belongs.  One CAN blame NASA management of
the day, but to my mind it makes more sense to blame a micromanaging
congress that forced the choice between building a vehicle that was
initially cheap or not building anything.

Now, if you were running a space program and had a choice between
using some optimistic numbers and opting for a design you CAN have,
knowing that it will be expensive to run, and using pessimistic
numbers and not getting diddly (and hence essentially killing what was
going to be left of the space program), which would YOU do?

Oh, sure, there is more than enough blame to go around to NASA
management of those days over other decisions, but let's understand
how they are forced to operate by the process.  You want NASA space to
work better?  Change the process (like multi-year appropriations for
entier programs, so that Congress doesn't come back later and
'stretch' them out, nickel and dime them to death, etc.).

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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End of Space Digest Volume 16 : Issue 003
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