Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_3/V16NO329.TXT

Internet Message Format | 1993-07-13 | 36KB

Date: Thu, 18 Mar 93 05:10:59
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #329
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 18 Mar 93       Volume 16 : Issue 329

Today's Topics:
                        20Khz Power supplies.
                 cancel wars accountability (2 msgs)
                                 DC-X
             Dennis and new tech (was Re: Without a Plan)
                       JPL and goals and plans
                     Lunar ice transport (2 msgs)
                  NASA worships the God of paperwork
                         Pat & Fred on 20khz
                      Plans and political goals
                    Single Stage Rocket Technology
                        Space Digest V16 #324
                            Space markets
                    SpaceStation and SSTO (2 msgs)
    Water Simulations (Was Re: Response to various attacks on SSF)

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

From: Gary Coffman <ke4zv!gary>
Subject: 20Khz Power supplies.
Newsgroups: sci.space

Message-Id: <[e-mail]>
Keywords: Freedom Cut
Reply-To: Gary Coffman <ke4zv!gary>
Organization: Destructive Testing Systems
References: <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
Date: Wed, 17 Mar 1993 14:52:30 GMT
Lines: 55
Sender: [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]> [e-mail] (Pat) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>systems. It's cheaper, smaller, and lighter than the old brute force
>>methods of Tommy Edison and Georgie Westinghouse. Even Nicky Tesla
>>thought higher frequencies were a good idea for power distribution.
>
>You talk about them like they were close personal friends of yours.
>Did you go to school with them ;-)

Almost. :-) Forge and Foundry was still a required course at Tech when
I was there.

>>DC was a technology of the 90s, the 1890s. Try to move into *this*
>>century Pat.
>>
>I wasn't particularly advocating DC.  I thought 400 HZ was the way to
>go.  Sure you have to buy out of aircraft catalogs,  but then the
>parts are halfway to space qualified.  You must be getting
>hardening of the arteries:-)
>
>The only reason I thought DC was an idea, was most of our manned
>space background is in DC.

400 Hz has the advantage of having off the shelf aircraft parts
available. That's not to be sneezed at in times of tight funding,
but aircraft electrical parts always seem overpriced to me. For
real cost savings just use 60 Hz and buy at Sears. But 20 kHz does
have technical merits that would warrant it being considered by an
_R&D_ chartered organization as opposed to a strictly commercial
enterprise.

DC has been used on our missions because it's simplest when power
demands are modest, voltage requirements are the same for everything,
busses are short, and everything is battery powered. When power demands
become more complex, it's better to convert to AC where voltage step ups
and step downs are easier, cheaper, and more efficient, where buss conductors
can be of a lighter gauge (a not trivial concern in a large structure), and
where regulation can be improved, simplified, and made lighter. Those are
all desirable attributes in a weight and power constrained space system.

There's nothing magic about 20 kHz, but it is a good compromise frequency
between skin effect problems at higher frequencies, and weight and size
problems at lower frequencies. Personally I'd choose some frequency like
15.749 kHz because our base ten natures tend to make lots of things run at
multiples of 10 and I'd like to avoid harmonic interference. Not to mention
that there are hundreds of millions of pieces of equipment that already
use that frequency and all the technical issues have been solved years
ago.

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: 17 Mar 1993 17:02:51 GMT
From: David Weingart <[e-mail]>
Subject: cancel wars accountability
Newsgroups: comp.org.eff.talk,alt.privacy,sci.space,sci.astro,news.admin.policy

In article <[e-mail]>, [e-mail] (Jay Maynard) writes:
|> [Bogus Distribution: inet changed to world.]
|>
|> In article <[e-mail]> [e-mail] (Lazlo Nibble) writes:
|> >Depew's superiors and Julf are, in each case, the person most immediately
|> >empowered to take care of the perceived problem.  You won't find an exact
|> >parallel between the two situations, but this is a reasonable one.
|>
|> Not even close. Julf can't get the coward fired from his job.

On the other hand, posting flames and personal attacks doesn't normally
_deserve_ firing (nor did ARMM, BTW, since it was deactivated, although
removal of net.access, either permanently, or some specified period for
abuse of power might be in order)

--
73 de David Weingart  KB2CWF    In the event I am captured or killed, the
[e-mail]       Cornell University Medical College and the
[e-mail]   Department of Academic Computing will disavow
[e-mail]      any knowledge of my opinions.

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

Date: Wed, 17 Mar 1993 18:24:17 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: cancel wars accountability
Newsgroups: comp.org.eff.talk,alt.privacy,sci.space,sci.astro,news.admin.policy

In <[e-mail]> [e-mail] (Lazlo Nibble) writes:

>[e-mail] (Jay Maynard) writes:

>> The coward asked folks to flood Dick Depew's superiors with mail and
>> phone calls. Not only is [e-mail] NOT the coward's superior,
>> he's not even at the same institution (most likely).

>Depew's superiors and Julf are, in each case, the person most immediately
>empowered to take care of the perceived problem.  You won't find an exact
>parallel between the two situations, but this is a reasonable one.

Except, of course, that we can't have Julf get Mr Anon E. Mouse fired
or call for having his supervisor or department head mail bombed.
Hey, maybe there's something to this anonymity thing after all, but
only as a defense against the sort of people who seem to be using it
(and one other who comes to mind).

--
"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: Wed, 17 Mar 1993 17:45:21 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: DC-X
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Andy Cohen) writes:

>I had the incredible honor to get a detailed tour of the Delta Clipper-X...
> and I'd like to try sharing some of it with you all....

Thanks.  It's appreciated.

>The landing gear are not strong enough to hold a fully loaded
>DC-X...instead a launch frame holds the infrastructure and during flight at
>some point the foor "legs" extract then help absorb shock at
>landing...along with the engines......

Can they vent enough fuel quickly enough to prevent loss of vehicle if
something goes wrong early and they need to land it *fast*?

>They were MOST interested in hearing about YOUR support.

Can there really be any doubt?  Hey, maybe they can get a net
connection for all that copius spare time in those 40 hour days?  ;-)

>I agreed to carry hard copies of posts from here to their facility as a
>morale booster.....they say they work 40 hour days there....... and are
>looking forward to months in the desert.......They do not know about how
>this communitee feels about their efforts...so SPEAK UP!!

Well, I hope they know that there are a lot of people who consider
what they're doing to be the best hope for a real future in space for
this country and that we feel that this vehicle (and its follow-ons)
should be funded right up through the first payload delivered to
orbit.

Maybe they could collect hardcopy of all of these and have their
management forward them to Congress?

--
"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: 17 Mar 1993 10:08 PDT
From: "Horowitz, Irwin Kenneth" <[e-mail]>
Subject: Dennis and new tech (was Re: Without a Plan)
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]>, [e-mail] (Bill Higgins-- Beam Jockey) writes...
>Which, it is worth pointing out, is trying out risky new technologies
>in its computer, solar cells, and imaging device.  This is something
>that Nick, Henry, and many others advocate strongly.  If SEDSAT-1 is
>successful, these gadgets will have a track record and people will be
>willing to incorporate them into future satellites. (Though I think
>Dennis's payload goes up on the *second* SEDS launch, not the current
>one.)
>
Indeed...SEDSAT-1 is scheduled for launch in about one year.  The mission
that is being launched this month is the first mission in NASA's SEDS
program (Small Expendable Deployer System...not to be confused with the
other SEDS, Students for the Exploration and Development of Space), but
is not the satellite that Dennis and his team have been laboring on for
the past few years.
-------------------------------------------------------------------------------
Irwin Horowitz                        |
Astronomy Department                  |"Whoever heard of a female astronomer?"
California Institute of Technology    |--Charlene Sinclair, "Dinosaurs"
[e-mail]                |
[e-mail]                 |
-------------------------------------------------------------------------------

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

Date: Wed, 17 Mar 93 17:29:58 EST
From: Tom <[e-mail]>
Subject: JPL and goals and plans

Pat <[e-mail]> sez;

>[Nick's suggestions for JPL]
>I think Nick is a *little* off base in suggesting changes for JPL.
>JPL  A) Has their plate pretty full doing existing missions.

Including having them cancelled, fighting for funding, etc.  The point
is, the talent isn't being used on JPL's 'prime directive'.  The same
effort could do more missions than are being done now.  Look how much
effort is thrown down the tubes when even small missions get canned.

>     B) is oriented to certain mission types, and prospecting
>        is a little out of their balliwick..

I disagree here.  Sure, major prospecting and planet-side exploration
is heavy-duty stuff.  But, we don't even know where the best place
to look for minerals and volatiles is.  Finding that out would
require a fleet of small, relatively cheap probes.  That is right
up JPL's alley.  Galileo is a great example of such.

Once we find resources up there, let whoever wants them to worry
about how.  But until we find them, no one will try to use them.
That's pretty self-evident, but NASA's actions suggest that the
major decision makers haven't a clue.

>The basic science needs to be done,  what we need to do is
>get basic operating costs in space down by 2 orders of magnitude.
>Then the market will do the rest.  Until we stop operating in
>this psuedo-market,  no-one will have any interest in cutting costs.

This is a little confusing.  I thought the market would bring the
costs down, rather than just 'the rest'.  NASA sure hasn't done
anyhting in terms of dropping costs lately, so if the market can't
bring them down, either, is it possible for them to drop?

>Space has comsats,  but that is being serviced by existing vehicles
>and systems,  plus bandwidth seems like a limited resource.
>plus the FCC and NASA have far too much influence on this market.

They have an effective monopoly, in the US.  NASA chooses vehicles, FCC
chooses bands and protocols.  Is there much else in comsats?  The
satellite, but it must fit NASA/DoD vehicles.
I don't trust a managed market to be an accurate reflection of demand.

>What we need to do is develop things that are best done in space and
>that will drive the market up there.

Before that, we need to know what kinds of useful things are out there.
Heading out to set up operations with no idea will be an incredible
waste of time and effort, as potential investors know.  Naturally, this
kind of thing needs just what JPL does best, but it gets ignored,
because it isn't flashy, national-prestige-oriented, or an exuse to
hire more people.  Business-as-usual applies to political infighting,
not services :-)

If we knew the resources, there would be a lot more 'vision' when
it came to drawing up Plans, Goals, or market analyses.   So far,
the Plans and Goals I've seen take this as a minor consideration,
at best.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: Wed, 17 Mar 1993 15:01:39 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Lunar ice transport
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ross  Borden) writes:
>    The ideas suggested for cable cars, railroads and pipelines are
>interesting (I especially like the pipeline), but they all involve a
>*substantial* amount of civil engineering.  The main advantage of the mule
>train approach is that there is minimal route preparation.  You simply
>survey the route (with as many detours as necessary) and use 'dozers &
>dynamite where it's unavoidable.
>    Of course, it could easily be the case that the terrain is much
>too rough for any overland route to be feasable.
>    Having said that, I do like the pipeline.  While the start-up
>costs are greater, the high potential throughput and low operating costs
>are attractive.
>    To overcome the problem of freezing at night, the pipeline could
>be buried in the regolith (an excellent insulator).  Does anyone know
>what the mean temperature of regolith is at, say, 2 meters ?  The
>cost of ditch digging would have to be balanced against the increased
>capacity.

Well as the pipeline originator, I'd point out that burying the pipe
would negate the solar heating that makes the steam to power it. That
may be worthwhile to address full time usage, and as a hedge against
micrometeorite damage, however.

>    Another potential problem solved by burying the pipeline is micro
>meteorite punctures.  What is the flux of micro meteoites at the lunar
>surface ?   Would it be a long term problem for an unburied pipeline ?

I doubt it would be a serious concern, but I don't have hard data.

>    Also, a pipeline would require some measure of refinement at
>the poles, as you do *not* want to be pumping muddy, gritty water.  To
>take it a step further, you could perform the electrolosis at the pole
>and pump the H2 and O2 to the equator seperately, though that would be
>outside the scope of the design project.

The idea is to be delivering *steam*. Some entrained grit wouldn't
be a serious issue, but large chunks could be a concern as it might
clog the pipe during the nighttime freezeout and not be able to be
cleared by morning heating. Running a cleanout plug through the pipe
around solar noon would handle smaller grit. This is a typical trick
used in oil pipelines.

>    A separate consideration is the useful lifetime of the project
>(be it mule train, pipeline, or ice-flinger.)  If the ice deposits will be
>exhausted in 30 years, a scheme with high start-up costs would be
>undesirable.  Were the students given an expected life span or are they
>just assuming an indefinite period ?

That's a good question. Pipelines are routinely installed to oil fields
that are expected to have a 30 year life, but single wells, or fields
with short expected lifetimes are handled by tanker truck. The relevant
issues are expected volume and expected duration of the transport need.

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: Wed, 17 Mar 1993 16:44:08 GMT
From: Henry Spencer <[e-mail]>
Subject: Lunar ice transport
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ross  Borden) writes:
>be buried in the regolith (an excellent insulator).  Does anyone know
>what the mean temperature of regolith is at, say, 2 meters ?

We only have a few data points, but they're all within a degree or two
of 255K.  The variation is from site to site -- the temperature at any
particular site is absolutely constant at that depth.
--
All work is one man's work.             | Henry Spencer @ U of Toronto Zoology
                    - Kipling           |  [e-mail]  utzoo!henry

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

Date: Wed, 17 Mar 1993 17:09:13 GMT
From: "Don M. Gibson" <[e-mail]>
Subject: NASA worships the God of paperwork
Newsgroups: sci.space

in defense of paperwork, i relate my NASA experience.

In article [e-mail], [e-mail] (Alan Carter) writes:
>....I do not deny that
>it is necessary for any project more ambitious than an afternoon
>spent in one's shed to store (often boring) information in a more
>reliable and accessable form than the human brain. The trouble is
>that it is easy for management to become focused on paperwork rather
>than the real goals of the project.
that is a management problem, not a paperwork problem.

>....Paperwork exists only to serve the original engineering goals, not the
>other way around. In order for the paperwork to remain honest, it must
>be subject to continuous engineering scrutiny. We do not know how to
>systematise this scrutiny, and have to fall back on the diligence of
>experienced engineers when we apply it at all. When management
>(especially non-technical management) is motivated to track and operate
>through paperwork because the paperwork *is* easy to systemise, and the
>paperwork universe can be freed of much of the mess of the real world,
>it is difficult to find anyone to give the engineers a mandate to provide
>scrutiny with a brief that amounts to little more than "keep your eyes
>open and your sense of trouble keen," and back them up.
>
>I'll offer two further aspects of this view of the engineering vs.
>paperwork dichotomy. Firstly, the paperwork model stresses the
>depersonalisation of the engineering process. You are supposed to be
>able to mow down engineers as in the final scenes of "Zulu", and more
>will pop up and take over their paperwork. The paperwork also means
>that the structure and activities of the team can grow to the point
>where no one individual can comprehend even all the parts that they
>directly interface to. The engineering model identifies individuals
>motivated and able to have creative insights and organises their
>work such that they can see what is going on, so that their judgement
>and knowledge is applicable.
I worked for a couple of years on a NASA project.  That project may not have
been typical, but what is "typical" for a one-of-a-kind project?  The project
was Galileo, which designed and redesigned several times over an 11 year
period.  This was a large project involving as many as 500 people at a time.
Over time, folks came and went.  there were probably 4 generations of
designers.  I can honestly say, that if weren't for the "paperwork" and
documentation system, the project would be unfeasable.  folks came and
went and always took their brains with them.  if not for the
"paperwork system", replacements would be useless for many years.
good procedures, requirements, checklists, dictionaries and other documents
 prevent wasted effort.  could anything be worse than having to
re-invent the wheel ever year?

>
>Secondly, while it does nothing whatsoever to assist with the positive
>side of a project, the creative judgement I referred to above, the
>paperwork model does wonders when it comes to identifying individuals
>who can be deemed to be "at fault" after a mishap. The engineering model
>is to do with getting it right, the paperwork model is to do with
>getting it wrong. I have heard it argued that if everyone is busy covering
>their backsides then no mistakes will be made, but this is quite fallacious.
>Nothing would ever get done at all if people didn't take risks every day.
we had a procedure for taking risks.:)  actually, a good paperwork system
allows a rookie to take the same "risks" (with the same safety) as a
person with many years of experience.  It was not my exprience that
paperwork was used for fingerpointing.  It was a team effort and the
paperwork helped us look out for each other.

--DonG

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

Date: Wed, 17 Mar 93 15:18:23 EST
From: Tom <[e-mail]>
Subject: Pat & Fred on 20khz

Gee, you two sure say 'gee' a lot.   May I suggest you branch out with
'well', 'you see', or perhaps even 'the thing is..' :-)

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: Wed, 17 Mar 93 14:58:06 EST
From: Tom <[e-mail]>
Subject: Plans and political goals

N Szabo sez;
>>Until we _lose_ the delusional, cultish cant of Wingo's, that our
>>vision must be one (his) and must never change, regardless of
>>changes in technology, politics, etc., NASA and space fans will
>>continue beating our heads against a brick wall.

Some nameless guy (I only see his/her address) replies;
>However, Dennis's One True Way is based upon bending metal and hands-on work.
>You've just got your hand out for money for a lot of politically unrealistic
>projects.

I am curious.  Do you mean 'politically unrealistic' as in "Democracies
never support good ideas", or do you mean it more like "I, in my infinite
wisdom, can accurately predict what 200 million people would support"?
Or are you a true cynic, where political reality means congress-whim, (which
you understand best, apparently) and citizens' concerns don't mean cow doots?

BTW, Nick never asked _me_ for any money.

>                   [e-mail]                        < --

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: 17 Mar 1993 17:10:37 GMT
From: Andy Cohen <[e-mail]>
Subject: Single Stage Rocket Technology
Newsgroups: sci.space

The following comes from the Delta Clipper public relations
flier....enjoy....

Single Stage to Orbit

Single Stage Rocket Technology ProgramBreaking the
SSTO Barrier

What Is Single Stage to Orbit?

Single Stage to Orbit (SSTO) is the capability to take off from earth,
achieve earth orbit, and return to land with the same vehicle. SSTO
capability, which includes safe abort and return to base any time
during launch, is a breakthrough in launch vehicle technology and
operations. In the highly competitive international launch service
business, SSTO provides this nation the low-cost advantage.

MDSSC's SSTO craft, named the Delta Clipper, is designed for
vertical take-off and landing. It is capable of placing 20,000 Ib. of
payload in low earth orbit or 10,000 Ib. in polar orbit. The reusable
craft is propelled by liquid oxygen/liquid hydrogen rocket engines.

The Delta Clipper design achieves airplane-like operations for
rapid vehicle turnaround and low cost per flight. Delta Clipper
meets the broad set of civil, commercial, and military space
requirements. It will enable safe, low-cost transfer of people and
cargo to and from space, dramatically increasing the potential
uses of space travel.

Why SSTO Now?

The idea of building a single-stage-to-orbit rocket is not new. Thirty
years ago, SSTO concepts were assessed and found to be
infeasible. Since then, advances made in materials, structural
designs, aerodynamics, propulsion, high-speed processing, and
autonomous control have made possible a lightweight, rugged
vehiclethe Delta Clipperwhich is capable of carrying out
responsive and sustained operations.

What is the Singie Stage Rocket Technology Program?

The Single Stage Rocket Technology program is an SD10 initiative
to demonstrate technology readiness. Under a 2-year, $58-million
Phase 11 contract, MDSSC and its teammates are using a rapid
prototype approach to design and build a one-third-size
experimental vehicle the DC-X, and ground support and
operations systems which, through a series of suborbital flights,
will:

 Verify vertical takeoff and landing

 Demonstrate subsonic maneuverability

 Validate "airplane-like" supportability/maintainability
concepts

 Demonstrate rapid prototyping development approach

Demonstration flights start in the spring of 1993 at White Sands
Missile Range in New Mexico. Results from flight and ground
turnaround tests will be used in a follow-on program. Follow-on
options include: (l) An SD10 program to develop a suborbital
reusable rocket for SD10 systems testing; (2) A national program to
develop a full-scale orbital prototype called the DC-Y.

The Delta Clipper Team
MCDONNELL DOUGLAS SPACE SYSTEMS COMPANY
Douglas Aircraft Co.  McDonnell Aircraft Co.  McDonnell Douglas
Electronic Systems Co.
McDonnell Douglas Missile Systems Co.  McDonnell Douglas Research
Laboratories
Pratt & Whitney  Scaled Composites
Aerojet  Eagle Engineering  Harris  Honeywell
Martin Marietta  Messerschmitt-Bolkow-Blohm
Fluor Daniel  SpaceGuild

MDSSC is now MDA or McDonnell Douglas Astronautics.
SSTO is now SSRT or Single Stage Rocket Technology.

I got detailed vugraphs which I'll be scanning in and translating to GIF
files....
WHERE DO YOU GUYS WANT EM FTP'd TO???????

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

Date: Wed, 17 Mar 93 15:27:30 EST
From: Tom <[e-mail]>
Subject: Space Digest V16 #324

D wingo sez;
>>The problem with 20Khz per se is that some women would not be able to stand
>>being around it, as a few women can hear frequencies that high. I kinda
>doubt this is a problem since many computer monitors also run in this frequenc
>>domain.

>Actually, a few men (myself included) can hear that high.  I can hear

Quite true.  Whether you can hear your TV or monitor is a good indication
of your hearing ability, as the fringe frequencies are usually lost
first.  Also, response to the constant sound is usually the cause of
VDS, or Video-Display-Syndrome, or whatever they call it:  Headaches,
Nausea, short tempers, high stress.

The bad news is that these frequencies can affect you this way, regardless of
whether you can actually hear it, since it's near the frequency of your
nervous system.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: Wed, 17 Mar 93 18:03:45 EST
From: Tom <[e-mail]>
Subject: Space markets

From: Pat <[e-mail]>

>But [Szabo] has one critical valuable point to make.
>That is a sustainable economy must be the basis of space  activities.

I'd have to say his other view, which I share, that NASA operations
have blocked, not fostered, the creation of sustainable markets in
space, is valuable as well.

>To date, manned space has not served market niches.

I like the idea of selling advertising and movie-making rights on our
current space operations.  If I remember right, NASA has turned it
down, for National Prestige reasons, I imagine.  Tell you what;
I'd have a lot more pride in my Nation if it's agents got with it.

Tourism might have a decent market, if DC fulfills it's design goals.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: Wed, 17 Mar 1993 18:03:46 GMT
From: Scott A Koester <[e-mail]>
Subject: SpaceStation and SSTO
Newsgroups: sci.space

   Here's a question that just popped into my mind and I decided to post it
here to see what you netters think about it.  With SSTO coming around, and
quite possibly having this transfrom into the DC-Y program, has any
consideration been done, on maybe having these craft dock with the SSFII?
Is this being incorporated into the redesign or thought about at all, or are
they working strictly on the premis that the shuttle is what we have now, this
works and will still work, so why plan for something like the DC-Y which may
never actually fully come around?
  If the DC-Y does come into full bloom, are the DC-Y designers thinking about
having the craft (actually I should say the SSTO designers) dock with a
station at all?  If so, the SSTO program could also help in keeping the
station supplied and wouldn't force the shuttle to an increase in pace
when it comes to turnaround times and launch schedules.
  What do you people think?  Is my thinking off on this?



Scott Koester

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

Date: 17 Mar 1993 18:26:46 GMT
From: Andy Cohen <[e-mail]>
Subject: SpaceStation and SSTO
Newsgroups: sci.space

In article <[e-mail]>,
[e-mail] (Scott A Koester) wrote:
>
>
>    Here's a question that just popped into my mind and I decided to post it
> here to see what you netters think about it.  With SSTO coming around, and
> quite possibly having this transfrom into the DC-Y program, has any
> consideration been done, on maybe having these craft dock with the SSFII?
> Is this being incorporated into the redesign or thought about at all, or are
> they working strictly on the premis that the shuttle is what we have now, this
> works and will still work, so why plan for something like the DC-Y which may
> never actually fully come around?
>   If the DC-Y does come into full bloom, are the DC-Y designers thinking about
> having the craft (actually I should say the SSTO designers) dock with a
> station at all?  If so, the SSTO program could also help in keeping the
> station supplied and wouldn't force the shuttle to an increase in pace
> when it comes to turnaround times and launch schedules.
>   What do you people think?  Is my thinking off on this?
>

The DC-Y payload will not be nearly as large or useful as the shuttle
payload bay....

First fight for Delta Clipper before you ask these not-really-off-base
questions.  Right now DC-Y is not a real program....i.e., not funded.  The
govt is waiting to see DC-X fly and land and fly and land, etc......

Next lets see DC-Y be successful.....

In the meantime......lets see if SSF can be the least bit successful as
well.....  The way things are going DC-1 will beat SSF to orbit!!! (I know,
I'm being facecious....sorry....can't help it....)......

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

Date: Wed, 17 Mar 1993 17:54:50 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Water Simulations (Was Re: Response to various attacks on SSF)
Newsgroups: sci.space

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

>>More importantly, NASA put a huge amount of faith in those tanks with
>>almost no real life experience to see just where the shortcomings are.

>Hey Allen I don't know how old you are but do you remember the old days at
>NAsa? ALL of the EVA's for Skylab were practiced here at MSFC before
>implementation....

You miss my point Dennis. I think water tanks and practicing on them is
a great idea. However, to assume that we can corelate actions in the tank
to the actions needed to assemble a large space structure (like Freedom)
in free fall is foolish.

The bottom line remains that we have nowhere near the EVA experience base
to practice any but the most simple EVA activities with any degree of
confidence.

>What about all of the Gemeni EVA's (well a couple of them) They were done
>in the tank first.

And I don't think any went as expected in flight. That was to be expected
in those early days. The idea is to get experience doing EVA so that you
can corelate EVA actions to water tank actions. NASA should have been
doing this but prefered to defer the problems and hope they went away.

>Do your remember the EVA's done before Challanger where trusses were built
>and Large solar arrays were deployed and many many other station type tasks?

I remember a small portion of truss being built and the automatic
deployment of some solar arrays. They where a good start but please
don't confuse them with the sort of effort needed to understand the
problem.

>The primary problem that was faced on the Intelsat mission is that the
>tank simply cannot accurately mimic the moments of inertia of large
>structures in orbit.

You mean like space stations? Congrats Dennis, you have found a
problem with Freedom construction: the tanks cannot provide a suitable
simulation for the construction of Fred.

>Maybe they need to look at regimens to compensate
>better for this difference between water and vaccuum.

Except that the designs and procedures for assembly are already
pretty much done (at least for the current design). It's too late
to do the work since any problems found would result in billions
more in added costs while the problems are found.

Now if the early EVA experiments had continued and been added to we
would have found the problems (if any) years ago and fixes would
already be incorporated in the design.

   Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------91 DAYS TO FIRST FLIGHT OF DCX-----------------------+

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End of Space Digest Volume 16 : Issue 329
------------------------------