OSP: reliability and survivability

In deciding whether or not to fund NASA's proposed Orbital Space Plane
- a "space taxi" dedicated to crew transport, in contrast to the
current "space truck" - Congressional mavens are making a faulty
assumption. That is that because OSP will be launched on unproven
Delta and Atlas-family rockets, it will be fundamentally no more
reliable than the Shuttle. Because OSP will be costly, it follows that
it makes more sense to upgrade the Shuttle than to build a new
spacecraft.

This is correct on its own narrow terms - rockets tend to explode at
least 1% of the time, despite the best efforts of engineers. However,
putting the OSP on top of the launch stack makes it an inherently
survivable vehicle; rockets can drag the plane clear of a fireball,
and launch debris won't fall onto the vehicle. The OSP becomes its own
ejector seat.

The shuttle, in contrast, can be made more reliable but is inherently
unsurvivable. The Challenger and Columbia incidents only became
disasters because of the Orbiter's placement to one side of the launch
stack. One way round this is to build a B-1B type Crew Escape Module
into the middeck, but this would involve a partial rebuild of the
three remaining Orbiters.

No. Don't upgrade the Shuttle beyond the measures suggested in the
Gehman report. Let's put all our energies into building a reliable,
survivable replacement. Fly the Shuttle only as many times as are
needed to complete the Station, then - ASAP - put these dinosaurs into
mothballs. Time for a change.

Edwin Kite
undergraduate
Cambridge University, UK

"Edwin Kite" wrote in message
om...
In deciding whether or not to fund NASA's proposed Orbital Space Plane
- a "space taxi" dedicated to crew transport, in contrast to the
current "space truck" - Congressional mavens are making a faulty
assumption. That is that because OSP will be launched on unproven
Delta and Atlas-family rockets, it will be fundamentally no more
reliable than the Shuttle. Because OSP will be costly, it follows that
it makes more sense to upgrade the Shuttle than to build a new
spacecraft.

This is correct on its own narrow terms - rockets tend to explode at
least 1% of the time, despite the best efforts of engineers. However,
putting the OSP on top of the launch stack makes it an inherently
survivable vehicle; rockets can drag the plane clear of a fireball,
and launch debris won't fall onto the vehicle. The OSP becomes its own
ejector seat.

The shuttle, in contrast, can be made more reliable but is inherently
unsurvivable. The Challenger and Columbia incidents only became
disasters because of the Orbiter's placement to one side of the launch
stack. One way round this is to build a B-1B type Crew Escape Module
into the middeck, but this would involve a partial rebuild of the
three remaining Orbiters.

No. Don't upgrade the Shuttle beyond the measures suggested in the
Gehman report. Let's put all our energies into building a reliable,
survivable replacement. Fly the Shuttle only as many times as are
needed to complete the Station, then - ASAP - put these dinosaurs into
mothballs. Time for a change.


You guys just don't get it, do you? All technical and engineering analysis
will say that the Shuttle is generally safe and logically speaking it makes
more sense to keep the Shuttle flying for as long as needed. However,
politicians and the U.S. public aren't on the same frequency with engineers.
Their call for a Shuttle replacement is purely based on the *subjective*
feeling that the Shuttle is unsafe and is tainted. Yet, these are the people
that decide wether the Shuttle will be replaced or not. Conclusion: the
Shuttle will be replaced with a decade. As soon as the OSP is flying, I'll
bet you that NASA will present a plan to take the remaining Shuttles out of
service.

Ultimate Buu wrote:

You guys just don't get it, do you? All technical and engineering
analysis will say that the Shuttle is generally safe and logically
speaking it makes more sense to keep the Shuttle flying for as long as
needed.

I do not agree to this statement. There are several flaws in the shuttle
system,making it unsafe, which could only be solved by a complete
redesign. (Eg. Tank isolation, hydrogen fuel lines which leak every few
launches)

However, politicians and the U.S. public aren't on the same
frequency with engineers. Their call for a Shuttle replacement is
purely based on the subjective feeling that the Shuttle is unsafe and
is tainted. Yet, these are the people that decide wether the Shuttle
will be replaced or not. Conclusion: the Shuttle will be replaced with
a decade. As soon as the OSP is flying, I'll bet you that NASA will
present a plan to take the remaining Shuttles out of service.

Do you really think NASA will be able to build OSP, or any other manned
craft? Considering their performance in the last two decades, I really
doubt OSP will succeed, rather than being scrapped midway because of cost
overruns and underperformance.

The US should put the remaining shuttles into museums, maybe after some
last missions like launching ISS-parts which cannot be done otherwise.
However, the shuttle was a try at building a low cost manned launcher
which did not succeed, and rather than fix what cannot be fixed the US
should build one or more successors incorporating the lessons learned.

Robert Kitzmueller

Ultimate Buu wrote:

You guys just don't get it, do you? All technical and engineering analysis
will say that the Shuttle is generally safe and logically speaking it makes
more sense to keep the Shuttle flying for as long as needed.

The flat failure of any *economic* analysis to support the shuttle is the
problem. Engineering analysis is a strictly secondary problem.

However,
politicians and the U.S. public aren't on the same frequency with engineers.
Their call for a Shuttle replacement is purely based on the *subjective*
feeling that the Shuttle is unsafe and is tainted.

Seeing as we've had two LOO/LOC accidents in 113 flights, it seems to me
there is pretty *objective* reason to doubt the safety of the
shuttle. Engineering analysis may show that if all the right measures are
taken and all the right procedures are followed everything will be OK. No
amount of analysis can guarantee that the procedures will in fact be
followed, nor the measures taken. In fact, we have clear evidence based on
experience to suggest that at least some procedures will not be
followed. The logical conclusion is that the design must allow for the
fact that the vehicle will be operated by humans as opposed to the
flawless engineers assumed in NASA analyses. This requires serious
redesign or outright replacement of the shuttle.

.......Andrew

--
--
Andrew Case |
|

(Andrew Case) wrote:

Ultimate Buu wrote:

However,
politicians and the U.S. public aren't on the same frequency with engineers.
Their call for a Shuttle replacement is purely based on the *subjective*
feeling that the Shuttle is unsafe and is tainted.

Seeing as we've had two LOO/LOC accidents in 113 flights, it seems to me
there is pretty *objective* reason to doubt the safety of the shuttle.

That's not an open and shut case. Both losses, while certainly
chargeable to design, could have been avoided by reasonable
operational procedures.

Engineering analysis may show that if all the right measures are
taken and all the right procedures are followed everything will be OK. No
amount of analysis can guarantee that the procedures will in fact be
followed, nor the measures taken. In fact, we have clear evidence based on
experience to suggest that at least some procedures will not be
followed. The logical conclusion is that the design must allow for the
fact that the vehicle will be operated by humans as opposed to the
flawless engineers assumed in NASA analyses. This requires serious
redesign or outright replacement of the shuttle.

Anyone who believes that we can engineer a vehicle of air, ground,
sea, or space that will never suffer a LOC/LOV accident is living in a
fantasy world.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

The Ruzicka Family a écrit dans le message :
...

"Edwin Kite" wrote in message
om...
In deciding whether or not to fund NASA's proposed Orbital Space Plane
- a "space taxi" dedicated to crew transport, in contrast to the
current "space truck" - Congressional mavens are making a faulty
assumption. That is that because OSP will be launched on unproven
Delta and Atlas-family rockets, it will be fundamentally no more

By the time that OSP actually flys, both the Delta 4 and Atlas V will have
flown many missions, with both commercial and government payloads. Both
systems will be far from "unproven" by that time. In order to actually
FLY
the OSP, there will have to be some modifications made, especially with
regard to avionics, adapter interface, etc. ALL of these mods will be
made
with the intent of actually making the launchers even MORE safe and
reliable. Will they be 100% safe and reliable? No. No space launch
system
ever has been, nor ever will be 100% safe and reliable. But to say that
the
Delta 4 or Atlas V will be unproven by that time is not factually true.

Remember that Ariane V is supposed to be Man-rated ( triple redundancy ).
Would you take a flight on it at this time?

LooseChanj wrote:

On or about 8 Sep 2003 22:10:01 GMT, Derek Lyons
made the sensational claim that:
Anyone who believes that we can engineer a vehicle of air, ground,
sea, or space that will never suffer a LOC/LOV accident is living in a
fantasy world.

Engineering a vehicle that can't experience an LOC is easy. Just don't put
people on it!

That's fine, until you come to those times when people *are* the
payload....

And if the vehicle (not to mention many inanimate payloads like
satcoms, big space telescopes, or nuclear powered probes) is sufficently
expensive and valuable, you want just about as much certainty of its
ssuccessful flight and return, as if it *were* manned. Unmanned doesn't
always equal expendable.

Andrew Case wrote:
The flat failure of any *economic* analysis to support the shuttle is the
problem.

Actually the original analysis supported the shuttle of course. Probably
you meant *accurate* economic analysis :-)

Gotta thank Tricky Dicky Nixon for this one. Check it out:

http://www.spacedaily.com/news/shuttle-03p1.html

Very, very rough summary: 'oh yeah, we lied to congress big time, there
was no way we could or would launch 52 times per year which is what is
needed to make the Shuttle cost-effective, but Nixon knew that and
knowingly signed off on it anyway. p.s. didn't we mention how fragile
the leading edges are? Oops, I'm sure we must have.'

Lovely.

......Andrew

Ian Woollard wrote:

http://www.spacedaily.com/news/shuttle-03p1.html

Very, very rough summary:

Rougher summary; There is no evidence to cite this individuals
claims.

Rough, but true, statement: The journalistic and editorial standards
of Space Daily are low at best.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

On 6 Sep 2003 13:55:04 GMT, in a place far, far away,
(Edwin Kite) made the phosphor on my monitor glow in such a way as to
indicate that:

In deciding whether or not to fund NASA's proposed Orbital Space Plane
- a "space taxi" dedicated to crew transport, in contrast to the
current "space truck" - Congressional mavens are making a faulty
assumption. That is that because OSP will be launched on unproven
Delta and Atlas-family rockets, it will be fundamentally no more
reliable than the Shuttle.

While this is true, the theory is not that OSP will be more reliable,
but that it will be safer (i.e., provide a better chance of crew
survival).

Because OSP will be costly, it follows that
it makes more sense to upgrade the Shuttle than to build a new
spacecraft.

Actually, neither makes economic sense.

This is correct on its own narrow terms - rockets tend to explode at
least 1% of the time, despite the best efforts of engineers.

Expendable rockets do. We've no experience base with reusables, other
than Shuttle, which has never exploded...

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

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