Europe to Join Russia in Building Next Space Shuttle

On Mon, 22 Aug 2005 18:50:13 -0500, Chris J. wrote
(in article ):

Wasn't one of the early claims regarding it's modular design that
older modules could be replaced with newer ones?

Only theoretically; it was never seriously planned given the cost of
designing and building the first set of modules (costs NASA and the
contractor team realized all along would preclude it in actuality).

I may be in error,
but I thought I recalled that from when the project was in it's
proposal stages. I take it that is no longer the case, if it ever was?

I don't doubt NASA let people believe that it was a possibility - the
reality is that neither ISS nor SSF before it was ever planned to
remove and replace modules. The modules themselves and all equipment
inside them were originally spec'd for 30 year on-orbit operational
lifetimes. This was decreased fo 15 years following the SSF CDR in
1993, mostly as a way to reduced projected final dev and qaul costs and
due to a grudging realization by NASA that a 30 year life was going to
cost way in excess of a 15 year life.

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"Jorge R. Frank" wrote:

John Doe wrote in :

The next step in space evolution would be to have the tools and
documentation to allow the ISS crewmembers to perform the forensic
analysys of failed components. (assuming CMGs could be fitted through
airlock hatch, or at least a CMG with creative use of an empty MPLM
with arm.

And of course they will need all the microscopes, diagnostic software,
chemical analysis, etc.. etc.. It's a long list of equipment and
disciplines to do that sort of analysis on any random hardware.

That paradigm shift implies a different set of "virtues" for subsystem
design: everything must be designed for crew servicing, and to the extent
possible, subsystems should use a minimum number of common components. That
in turn will minimize the number of tools and spare components that must be
carried

Only then, I believe, will onboard forensics be truly practical.

Not even then. If the problem is because that batch #2007-34A of the
adhesive used in the manufacture of the printed circuit board dwg#
CMM-087-93457 REV A was contaminated [1] - then no, it won't be
practical. The astronauts won't have the records or analytical tools
to examine the components to that level.

Worse yet, is when the problem is a 'virtual' one. (Item X rev A will
work with item Y rev A and B but not rev C. Meanwhile X rev B will
work with all versions of Y. Finally, X rev C will work with all Y
revision levels except *some* Y rev B and *some* Y rev C.) That
needs a large number of installed components and significant
statistical analysis plus and A-Ha! moment or two. [2]

The SSBN force tried for years to move more forensics forward - I.E.
onto the hulls. They eventually gave up because the costs were too
high (in dollars, weight, and volume) and the likelihood of success
too low. On orbit forensics becomes reasonable when the cost of an
hour and a pound on orbit becomes insensibly different from the same
figures on Earth, and not a moment before.

D.

[1] Don't laugh - We had to swap out several guidance systems on our
birds because of a problem of about that level. It happens.

[2] Been there, done that too. The basic problem was tolerance creep
between revisions and manufacturers - and that not all possible
squares on the matrix had actually been tested during qualification.
--
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-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

(Derek Lyons) wrote in
:

"Jorge R. Frank" wrote:

John Doe wrote in :

The next step in space evolution would be to have the tools and
documentation to allow the ISS crewmembers to perform the forensic
analysys of failed components. (assuming CMGs could be fitted
through airlock hatch, or at least a CMG with creative use of an
empty MPLM with arm.

And of course they will need all the microscopes, diagnostic software,
chemical analysis, etc.. etc.. It's a long list of equipment and
disciplines to do that sort of analysis on any random hardware.

That paradigm shift implies a different set of "virtues" for subsystem
design: everything must be designed for crew servicing, and to the
extent possible, subsystems should use a minimum number of common
components. That in turn will minimize the number of tools and spare
components that must be carried

Only then, I believe, will onboard forensics be truly practical.

Not even then. If the problem is because that batch #2007-34A of the
adhesive used in the manufacture of the printed circuit board dwg#
CMM-087-93457 REV A was contaminated [1] - then no, it won't be
practical. The astronauts won't have the records or analytical tools
to examine the components to that level.

I was thinking of mechanical components rather than electronics. I agree
that redundancy in electronics will likely have to remain at the subsystem
level.

--
JRF

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check "Organization" (I am not assimilated) and
think one step ahead of IBM.

"Jorge R. Frank" wrote:

[ forensic analysis of failed components]

I was thinking of mechanical components rather than electronics. I agree
that redundancy in electronics will likely have to remain at the subsystem
level.

The same objections still apply - the astro's will easily be able to
determine that the 'drive preload torque tube' in the HDMSS[1]
cracked, but determining *why* it cracked may need sophisticated
analysis.

D.

[1] Handwaving Doo-hickey Mechanism Sub System
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Derek Lyons wrote:
The same objections still apply - the astro's will easily be able to
determine that the 'drive preload torque tube' in the HDMSS[1]
cracked, but determining *why* it cracked may need sophisticated
analysis.

If they could disassemble (as example) the CMG and find the failed
bearings unit, they could then ship that small unit back to earth on a
soyuz where the heavy duty forensics could be done. This would avoid
having to send the whole CMG unit back down.

And they could then ship a replacement bearings unit and the crew would
put everything back together. (assuming the CMGs had been designed to
be easily taken apart).

John Doe wrote:

Derek Lyons wrote:
The same objections still apply - the astro's will easily be able to
determine that the 'drive preload torque tube' in the HDMSS[1]
cracked, but determining *why* it cracked may need sophisticated
analysis.

If they could disassemble (as example) the CMG and find the failed
bearings unit, they could then ship that small unit back to earth on a
soyuz where the heavy duty forensics could be done. This would avoid
having to send the whole CMG unit back down.

True enough - still it demands documentation and training to support
such a disassembly.

And they could then ship a replacement bearings unit and the crew would
put everything back together. (assuming the CMGs had been designed to
be easily taken apart).

And theres the rub.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

"Derek Lyons" wrote in message
...
John Doe wrote:
And they could then ship a replacement bearings unit and the crew would
put everything back together. (assuming the CMGs had been designed to
be easily taken apart).

And theres the rub.

Indeed. I'm sure the designers of the CMGs didn't think that astronauts in
EVA suits would need to replace the high precision bearings on the CMG.
It's far easier to design the entire unit to be replaced, based on the
assumption that the shuttle would be flying routinely to ISS for the entire
life of the ISS program.

Jeff
--
Remove icky phrase from email address to get a valid address.

Scott M. Kozel wrote:
These are enough - the most advanced bomber of WWII, the first
supersonic transport, and the first space shuttle.

One useful acquisition out of three ain't bad

Cardman wrote:
I am now wondering if we stole some Soviet designs?

What I can never figure out is why nobody copied the T-34, not only the
best tank of World War 2 but a relatively simple design that wouldn't
have been that hard to copy.

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Russell Wallace ) writes:
Scott M. Kozel wrote:
These are enough - the most advanced bomber of WWII, the first
supersonic transport, and the first space shuttle.

One useful acquisition out of three ain't bad

Cardman wrote:
I am now wondering if we stole some Soviet designs?

What I can never figure out is why nobody copied the T-34, not only the
best tank of World War 2 but a relatively simple design that wouldn't
have been that hard to copy.

The German Panther tank had not a few T-34 elements included in it's
design, as the Panther was intended to counter the T-34, once the
German Army found out that the Soviets had the T-34.

The US tank lineage was a separate thing, and the M-26 Pershing
was the starting point that led to the M-47/48/49/60 series.

Andre

--
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Russell Wallace wrote:


What I can never figure out is why nobody copied the T-34, not only
the best tank of World War 2 but a relatively simple design that
wouldn't have been that hard to copy.


Actually, the T-34 had some drawbacks- for one thing, its periscopes and
gun sighting systems sucked- but it was pretty good and you could make
it in huge numbers using fairly low-tech production techniques.
The best WW II tank? Probably the Panther, although it was prone to
mechanical problems.
When the Germans ran into the T-34, they did give thought to making a
copy of it. They couldn't handle armor castings of the size used for its
turret though, and its aluminum block engine (based on an Italian
aircraft engine design) was beyond their engineering abilities. So they
built the Panther instead.

Pat