Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_0/V16NO072.TXT

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Date: Sat, 23 Jan 93 05:00:00
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #072
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat, 23 Jan 93       Volume 16 : Issue 072

Today's Topics:
          2001/2010 Rocket Engines - What are they? (3 msgs)
                                AmRoC
      Clinton's Promises (space) in Charlotte Observer (2 msgs)
                        Defuse Xray Experiment
                    Hewlett Packard conin space
                 Justification for the Space Program
                        Shuttle safety margins
                      Soyuz as an ACRV (2 msgs)
                            Space Shuttle
Stafford receives Congressional Space Medal of Honor [Release 93-14] (Forwarded)
              Subjective Safety Measure(Re: man-rating)

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Date: Fri, 22 Jan 93 10:31:24 PST
From: Richard Buenneke <[e-mail]>
Subject: 2001/2010 Rocket Engines - What are they?

I can't recall the technical details, but I seem to remember that the
Leonov was powered by a Sakharov drive. In the book, Sakharov was
rehabilitated by a more democratic Soviet government. When he returned from
his internal exile to the closed city of Gorky, he brought along thw work
he'd done on a fusion power system.

On this bit of future history (written in the early 1980s), Clarke batted
.333.  Sakharov was rehabilitated.  Unfortunately, he didn't invent a
fusion engine before his death. And while a vehicle named Leonev may
someday fly to Jupiter, it won't be carrying Hammer-and-Sickle markings.

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

Date: 22 Jan 93 04:21:36
From: Terence Chua <[e-mail]>
Subject: 2001/2010 Rocket Engines - What are they?
Newsgroups: sci.space

I seem to remember that the novel mentioned the use of a "Sakharov
Drive" - it sounded like a pulsed-fusion engine to me... I also
remember them mentioning propellant. I'm not sure if it was in
reference to their own engines or the ones on the Chinese ship Tsien,
who used Europa as a re-fueling point to gather water as extra
propellant.

--
-----------------------------------------------------------------------
Terence Chua, Dept of Laws, Queen Mary College, University of London
Snail Mail: 22 Courcy Road, London N8 0QH
Telephone: [phone]
E-Mail: [e-mail]
-----------------------------------------------------------------------
"I am not a free man, I am a lawyer!"

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

Date: Fri, 22 Jan 1993 17:35:17 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: 2001/2010 Rocket Engines - What are they?
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Bill Higgins-- Beam Jockey) writes:

>I always thought this technology [gas-core nuclear engines] was a trifle
>advanced to be ready in only 2001,

That depends on the type of gas core.  I believe that NASA's 1976 "Forecast
for Space" said the light-bulb variant, at least, could be ready well before
that time frame.  (Assuming development starting in 1976, that is.)


>but remember that Kubrick's people were busy little beavers
>in the 34 years following 1967-- they had dug out underground hangars
>on the Moon for their spacecraft, with elevators, had started regular
>Pan Am service to orbit, had built half a space station.

>It is sad to think that *they* were supposed to be *us*. :-(

On the other hand, remember that Forbidden Planet, in the 1950's,
began with the narrator's voice saying, "In the last decade of the
21st Century, Mankind reached the Moon."  Rober Heinlein was a bit
more optimistic in "The Man Who Sold the Moon," placing the event
in 1979 but, of course, no one believed *that*.

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

Date: 22 Jan 93 18:04:00 PST
From: "RWTMS2::MUNIZB" <[e-mail]>
Subject: AmRoC

On 13 Dec 92 13:48:16 GMT, Dean Adams <[e-mail]> writes

>[e-mail] (George C Harting) writes:
>>I was wondering if anybody had any recent info about Amroc's Hybrid
>>rocket?

>FYI... they have a test firing for one of their latest motors
>scheduled on the 15th of this month out at Edwards AFB...

A local L.A. paper had an article on AmRoC just before the scheduled
test of their 250 klb thrust motor (derived from their successfully test
fired 70 klb thrust motor), but I haven't seen any follow up stories.
Does anyone know if the test was held?

Disclaimer: Opinions stated are solely my own (unless I change my mind).
Ben Muniz     [e-mail]    w(818)586-3578
Space Station Freedom:Rocketdyne/Rockwell:Structural Loads and Dynamics
   "Man will not fly for fifty years": Wilbur to Orville Wright, 1901

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

Date: 21 Jan 1993 20:44 CST
From: [e-mail]
Subject: Clinton's Promises (space) in Charlotte Observer
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Edward V. Wright) writes...
>In <[e-mail]> [e-mail] (rabjab) writes:
>
>>>        B. Support completion of the space station Freedom.
>
>>Looks like Clinton is going to make some rather severe cuts in space
>>projects.  And "supporting completion" doesn't mean actual completion.
>
>You don't understand.  NASA doesn't *want* Space Station Freedom
>completed.  Completing a project means you no longer have job
>security, which is why these things go on forever.  This is also
>why no one comes right out and opposes a project anymore.  Instead,
>they "support it as a research program" (as in Les Aspin's "I support
>SDI as a research program" or Gary Coffman's "I support SSTO...").
>That way, you not only ensure that nothing useful will ever get built,
>you also establish a permanent aerospace jobs program, and ultimately
>discredit anyone who supported the original project as anything more
>than a jobs program.
>
>

No you don't understand and your statement is a prime reason people like
you are not listened to at NASA. Even looking at the proposition from a
pragmatical political perspective, this statment of yours is false. Why?

If NASA drags their feet and does not finish the station costs soar and
nothing gets done. In this era of deficts and budget cuts at the drop a
political hat this path is suicide. NASA from the beginning has wanted to
finish the station for many reasons. Look at your congress critters for
the blame for the delays in station and the increased cost that has brought
due to maintaining the standing army that station design and ad infinitum
redesBign has caused.

Using your twisted logic I can argue that NASA would WANT to complete the
station because it will be much harder to kill it when it is in orbit and
the operational budget for the thing will help keep the fires warm there for
thirty years to come. This also leaves the door open for the continuation
of the shuttle program for all of the reasons that have been enumerated on
this net as well as many others that could be posed in your same faulty
reasoning.

I am insulted at your characterization of NASA, based upon years of work with
dedicated engineers and managers from Marshall, Langley, KSC, Lewis, JSC and
JPL. Ames is the only center that I have not worked with. Yours is a denegration
of the lives of those people who took lower wages to work in a job that they
love, in a societal realm that they love. Most could work at commercial
firms for more money. I don't think I have ever hear of anyone leaving NASA
for a lower paid postion.

I do agree that at NASA, as well as at any commercial company or university has
its share of duds. That is life. Lets see you do a good job with all of the
congressionally mandated procurement and other rules that they have to live
with. I have heard of stories like the one where an expansion board was ordered
for a Silicon Graphics workstation that was obsolete (9 months) before it
was delivered. This is a small part of the hell that the good people at NASA
have to live with.

At least they are there in the fight and trying do do something about it.
You and those like you who sit on the sidelines and rant and rave do nothing
for anyone or anything other than your own ego. This is one of the primary
reasons people like you are ignored by engineers and scientist at NASA who are
doing their best to help and lower the cost of the Exploration and Development
of Space.

A little bit of advice. If you see something wrong with NASA quit your whining
and do something about it. If you see a way to do it faster, cheaper, and or
better, then start designing it or implementing your plan in some way.
People that know will then see that you are doing something good and will help
you. This then will lead to you being recognized and if you then TALK to NASA
people as human beings instead of the enemy, THEN you might find that you have
a receptive ear that will not only help you, but will champion your cause
within NASA. These people are not stupid, if what you have actually makes
good sense and does a good job faster, cheaper or better, then you might
just find that NASA may adopt it.

There are pitfalls and there are managers and politicians that are more
concerned with their little 'ol empires and their way of doing things, but these
are simple obsticals to be overcome. Builds character, you ought to try it
sometime. So quit saying stupid things like you said in your post and
either do something or support those of us who are doing things that are
supporting doing things better or get out of the way.

By the way it is less than 60 days to the launch of the Small Expendable
Deployer System (SEDS 1) on a McDonnell Douglas Delta II. This is just one
of NASA's smaller, cheaper, better missions. It is a secondary payload on
a Delta which lowers the cost dramatically, and also it employs a
tether deployer based wonderfully on the KISS principle of deploying tethers.
It is the branchild of Preliminary Design (PD) at NASA Marshall, with the
end mass being built by Langley. The total cost of the development,
construction, launch, operations, and data reduction will be less than 8 million
dollars.

This tether mission is the result of a lot of hard work by a small group within
NASA. There will be two more similar missions, one with a conducting tether
in Calendar year 93 and early 94.

Everywhere I have been in NASA people have wanted to help us with our
satellite becauce it was "real hardware that will fly". There are many people
who have worked many hours at NASA on their own time to help us. Mayber you
ought to look at the subject and the people that you so easily dismiss

Dennis, University of Alabama In Huntsville

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

Date: Fri, 22 Jan 1993 15:48:06 GMT
From: Michael Jensen <[e-mail]>
Subject: Clinton's Promises (space) in Charlotte Observer
Newsgroups: sci.space

I must agree with Dennis from Hunstville.  As a extreemly low paid engineer,
I too find it sad when people continue to slam NASA for things that are out
of it's control.  We who work for NASA are accepting lower salaries, and
hard work not because we want to "rip off the taxpayer" or anything close, but
because we love what we do, and we love our country.  The only reason that
we have the significant majority of the problems we do encounter is because
the US Congress refuses to allow us to do our jobs the way they should be done.

*** Disclaimer - the rantings and ravings in this post are not nessesarily
those of NASA, the United States of America, any Federal Employee, the Federal
Government, or Walt Disney Inc. ***

--
Michael C. Jensen                [e-mail]
Electrical Engineering                [e-mail]
Valparaiso University                [e-mail]
"I bet the human brain is a kludge." -- Marvin Minsky

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

Date: Fri, 22 Jan 1993 17:04:58 GMT
From: Nick Haines <[e-mail]>
Subject: Defuse Xray Experiment
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Dick Edgar) writes:

   In article <[e-mail]> [e-mail] (Tom Schruefer) writes:
   >
   >>With the successful deploy of TDRS-F, STS-54's other primary payload bean
   >>operations. During orbital night, the Diffuse X-Ray Spectrometer will tke
   >>measurements of the x-ray background of the solar system's interstellar
   >>medium. This information will be used to answer questions about a nearb
   >>super nova that scientists believe occurred about 300,000 years ago.
   >
   >   Does anyone know which star they are talking about ???
   >
   This *may* have to do with the Geminga object, recently revealed by
   Rosat and GRO to be a pulsar with an age of about 300,000 years.  The
   best estimate of the distance is around 100 light-years, so is quite
   close in astronomical terms.

Yes, they're talking about Geminga. See a recent Science News for
more.

Nick Haines [e-mail]

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

Date: 22 Jan 93 15:36:48 GMT
From: Doug Mohney <[e-mail]>
Subject: Hewlett Packard conin space
Newsgroups: sci.astro,sci.space

In article <[e-mail]>, [e-mail] writes:
>
>Before you ask, the SPOC software is NOT available to the general
>public.  It includes a world map showing day/night and the current
>position of the Orbiter, updated in real time.

Like, bogus. Do you realize how much money NASA could make by selling it off to
Space Junkies at $50 a pop? :)


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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

Date: 22 Jan 93 18:50:00 PST
From: "RWTMS2::MUNIZB" <[e-mail]>
Subject: Justification for the Space Program

I know that the discussion regarding the justification for the space
program died out about 2 weeks ago, but I just bought a book related to
the subject and I was wondering if anyone on the net has read it.

It's called "Breakout Into Space, Mission for a Generation" by George
Henry Elias.  The cover blurb reads in part: "(the book) presents a
broadly, efficiently argued case for moving civilization beyond Earth's
limits and into the solar system. (Elias) explores the environmental,
economic,, and political benefits of space settlement.  Inhabiting space
is no longer science fiction, but human necessity - and destiny . . .
The establishment of a space civilization is an essential part of the
effort to preserve the environment, prevent global war, and provide a
stable economic future".

Any comments about the book, either pro or con?

Disclaimer: Opinions stated are solely my own (unless I change my mind).
Ben Muniz     [e-mail]    w(818)586-3578
Space Station Freedom:Rocketdyne/Rockwell:Structural Loads and Dynamics
   "Man will not fly for fifty years": Wilbur to Orville Wright, 1901

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

Date: 22 Jan 93 17:17:00 PST
From: "RWTMS2::MUNIZB" <[e-mail]>
Subject: Shuttle safety margins

On Date: Thu, 14 Jan 93 00:57:14 EST, John Roberts <[e-mail]>
writes:

>It turns out that with the measured wind patterns, if one of the SSMEs had
>failed (it didn't) right when the Shuttle was passing Mach 1.55, three of
>the struts in the structure would have had a safety factor of 1.36 (36%),
>while the target safety factor under those conditions is a minimum of
>1.4 (40%). Analysis of the situation and of the particular orbiter indicated
>that this safety factor was acceptable, so permission was granted to proceed
>with the launch.

Strictly speaking, the *safety factor* was not reduced.  The *margins of
safety* for the struts would have been reduced.  The following
definitions (not exact spec wording, but close to the point) may help:

Limit Load (or Stress): the maximum predicted structural load which may
be experienced by the vehicle while performing its mission.  This
typically defines either a "worst case" or statistically derived (e.g.
3-sigma) magnitude.  The SSMEs use a 2-sigma operations criteria, and the
rest of the structure may use the same.  Uncertainty factors may be included
in the calculations (varies from program to program but typically 1.5 at PDR,
1.25 at CDR, and 1.0 at FRR).

Allowable Yield Load: the maximum load the structure can withstand
without unacceptable permanent deformation.

Allowable Ultimate Load: the maximum load the structure can withstand
without collapse.

Factors of Safety (FS): the values by which the limit load is multiplied
to obtain the yield and ultimate loads that the structure is designed to.

Margin of Safety (MS) = [Allowable Stress/(Limit Stress x FS)] - 1

The FS is a traditional "fudge factor" used to account for uncertainties
such as variations in material properties, dimensional tolerances, etc.
The Shuttle payloads (and I assume the Orbiter as well) use 1.4 for
ultimate load.  A factor of 1.1 is typically used for yield load, but I
don't know if the Orbiter structural design uses that.  Recent work has
been done on SSME and SSF components to replace this traditional method
with probabilistic structural analysis which uses a statistical treatment
for uncertainties in both the applied load and material strength.

If a structure designed by this criteria has an Ultimate MS = 0.0, it
will collapse if the actual imposed loads are 40% higher than the maximum
expected.

<Pat was concerned by mechanical safety margins, and felt that the
<Shuttle operates within 5% of destruction for its major mechanical and
<structural systems.

Based on the information presented, it's unclear but I *think* that in
the event of a single engine failure, the struts have an Ultimate MS =
0.0.   It could thus be said that the Orbiter would then be flying within
40% of destruction (and possibly 10% of being deformed such that it would
need repairs).  In the case of the flight in question, where predicted
winds aloft were higher than those which were used to design the Orbiter,
it appears that the Ultimate MS was = -0.04 and it was flying within 36%
of destruction (6% of yielding).

<The spokesman (Brewster Shaw, Deputy Director of the Space Shuttle
<Program) replied that the safety margin stated is not to the point of
<destruction . . .

Does anyone on the net know what the actual Yield and Ultimate MS were
for this flight?  Given the fact that payload launch load analyses
typically take one year to complete, was the analysis for this launch
done "real-time", or were the results already available from previous
studies of possible flight envelope expansion?

<One of the questions during the press conference was "what if something
<additional had happened, and the stress was increased another 36%, so
<that zero safety margin was passed?"

The same thing that happens to bridges which are subjected to loads
beyond the maximums expected by the engineers, something breaks.  An
excellent book on the limits of engineering ability to predict the
behavior of structures and the public's expectations of these predictions
is "To Engineer is Human, The Role of Failure in Successful Design" by
Henry Petroski.  Has anyone else read this, and if so what did you think?

Speaking of bridges:
On Date: 20 Jan 93 17:49:34 GMT, Pat <[e-mail]> writes:
> Certain things must expect certain conditions.  Now i dont expect a bridge
> to withstand the North AMerican Fat ladies precision Hop SCotch squad :-)
> but i do expect it to withstand 3 cement trucks in close order.

Petroski's book describes the inadvertent proof test of the Golden Gate
Bridge performed by 250,000 pedestrians who packed onto the bridge on its
50th anniversary.  The bridge swayed several feet and its arch flattened out
as much as 10 feet.  If the bridge had collapsed under this unanticipated
load, would the engineers have been to blame?

Related to this subject, I am researching the use of traditional
uncertainty factors in defining limit loads in the fields of aerospace,
automotive, nuclear, etc.  It appears that very little has been formally
published in this area and the most of the information is in the brains
of the people who have done the work.  Any information in this area would
be greatly appreciated.

I apologize if this goes beyond the scope of sci.space.  Does anyone know
of any engineering (especially aerospace and/or structural) news groups?

Disclaimer: Opinions stated are solely my own (unless I change my mind).
Ben Muniz     [e-mail]    w(818)586-3578
Rocketdyne/Rockwell:Space Station Freedom:Structural Loads and Dynamics
   "Man will not fly for fifty years": Wilbur to Orville Wright, 1901

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

Date: 20 Jan 93  23:31:02
From: [e-mail]
Subject: Soyuz as an ACRV
Newsgroups: sci.space

DA>>Under the terms of the Launch Services Purchase Act, NASA is prohibit
DA>>from orbiting non-shuttle-specific payloads. Therefore,
DA>>using the shuttle to orbit Soyuz spacecraft contravenes the LSPA.
>
EH>Why do you assert that it is not STS specific, since the final design
EH>not yet established?  For example, the design might require a full
EH>load of fuel/oxidizer to do safe deorbit and landing, so it would need
EH>to be docked without using the propulsion system by placing it with th
EH>RMS on the Shuttle.

The final design of Soyuz was established in 1965 by Sergei Korolyov.
There have been modifications since. Soyuz is not a Shuttle specific
payload. Any attempt to call a Soyuz a shuttle-specific payload falls
under sophistry.

EH>>However, several U.S. commercial vendors can supply launchers that
EH>>can easily orbit a Soyuz for a more reasonable price than the shuttle
EH>>a nice side benefit, this would create a second means of access to sp
EH>>in the US, in case the shuttle fleet is grounded.
EH>
EH>The cost to orbit might be cheaper by commercial carrier, depending on
EH>how you do the accounting.  As we have seen here, the entire governmen
EH>uses different procedures for figuring the "cost" of something.  If th
EH>STS fleet is grounded, the only impact aside from STS-specific ops wou
EH>be on Freedom.  This might or might not be critical.

Since Freedom and shuttle will be the only manned space activities in
this country, grounding of the shuttle would mean the end of manned space
here. This might or might not be critical, depending on your point of
view.

___ WinQwk 2.0b#0

--- Maximus 2.01wb

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

Date: 20 Jan 93  23:40:04
From: [e-mail]
Subject: Soyuz as an ACRV
Newsgroups: sci.space

da>>Under the terms of the Launch Services Purchase Act, NASA is prohibit
da>>from orbiting non-shuttle-specific payloads. Therefore,
da>>using the shuttle to orbit Soyuz spacecraft contravenes the LSPA.

AW>In a perfect world you would be correct. However, it is currently too
AW>easy for NASA to declare a payload Shuttle specific.

I dare them to declare that Soyuz is shuttle specific. I double dare
them. Go ahead, make my day.


da>>However, several U.S. commercial vendors can supply launchers that
da>>can easily orbit a Soyuz for a more reasonable price than the shuttle

AW>As you well know, I have long supported exactly this. It is obvious th
AW>using non-shuttle based logistics systems are both cheaper and more
AW>reliable. The problems are political and not technical.


There is a grand compromise inherent in all this that may work out to
almost everyone's satisfaction:

The Russians want to launch US comsats on Proton from Baikonur.
Protons are significantly cheaper for geosynchronous launches than
US comemrcial launchers.

NASA wants to launch Soyuzes inside the shuttle.
US commercial launchers are significantly cheaper than shuttle flights;
however, Soyus would probably require at least five ELV launches per
year (compared to two shuttle flights).
Proton cannot loft a fueled Soyuz to Freedom's orbit, and is still
not man-rated.

The solution?

Allow US Commercial launchers to orbit the Soyuzes from the Cape.

Allow Proton to orbit as many comsats as US launchers orbit Soyuzes -
a one for one treaty, so to speak. Only NASA loses, except it gets
a cheap ACRV. The US commercial launch industry gets to survive,
and the Russians get some business.



___ WinQwk 2.0b#0

--- Maximus 2.01wb

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

Date: 22 Jan 93 07:32:50 GMT
From: David TW Lai <[e-mail]>
Subject: Space Shuttle
Newsgroups: sci.space

Hi,

    I wonder whether NASA will post article in this newsgroup (or
others) about future Space Shuttle missions?  Since I'm very interested
in viewing the Shuttle take-off in person, I am looking for ways to get
informed about future Space Shuttle missions.

                        Regards,

                            David.

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

Date: Fri, 22 Jan 1993 14:27:52 GMT
From: David Bultman <[e-mail]>
Subject: Stafford receives Congressional Space Medal of Honor [Release 93-14] (Forwarded)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Peter Yee) writes:

|> produced a report called "America at the Threshold," which is a
|> roadmap for the next 30 years of U.S. manned space flight.  He

How can I get a copy of this?

Thanks in advance,
--
David Bultman, [e-mail]    SAS Institute, Inc.
Core Research and Development        SAS Campus Dr, Cary, NC
[phone] x6875            27513-2414 USA

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

Date: 22 Jan 93 15:06:47 GMT
From: Henry Troup <[e-mail]>
Subject: Subjective Safety Measure(Re: man-rating)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Bruce
Watson) writes:
|>Contrary to all the movies we've seen, there has never been an elevator
|>fatality since Otis designed the safety features of the modern elevator
|>in the late 19th century.

There have been two in Ottawa, Canada in the last three years.  Neither
involved a falling elevator, however.  Both involved door problems,
people caught in the door and crushed aginst the door frames outside the
elevator.

I see your "never" and raise you two anecdotes.  If you call my bluff,
I'll have to research and give names and dates.  One was in the Lord
Elgin Hotel, the other an apartment building.

Henry Troup - [e-mail] (Canada) - BNR owns but does not share my opinions
                 "I am Salman Rushdie"

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

End of Space Digest Volume 16 : Issue 072
------------------------------