From Jon Berndt:
"Stuf4" wrote:

It is *easy* to augment the design of this pressure vessel so that it

It is? Care to elaborate on that assertion? "Easy"?

(see below)

then becomes a crew escape module. It is also easy to determine c.g.
limits of this module so that after orbiter breakup it has a stable
flight. An escape module design that would have permitted safe escape
for both -51L and -107 crews need not have had excessive weight.

These assertions seem to go against what I have read. Why do you say this?
Can you refer to some published studies?

I say this based primarily on the empirical evidence. The evidence
that Challenger's cabin and Columbia's cabin held together
significantly even though they *weren't designed* as escape modules.

JSC office MV-6 holds this responsibility today. Here is a link to
their document "Human-Rating Requirements" from June 1998:

http://www.hq.nasa.gov/office/codea/...documentd.html

Excerpt:

__________

Requirement 7:
A crew escape system shall be provided on ETO vehicles for safe crew
extraction and recovery from in-flight failures across the flight
envelope from prelaunch to landing. The escape system shall have a
probability of successful crew return of 0.99.

__________


These specialists seem to think that it's possible. And I don't know
of any major breakthroughs in crew escape technology that have changed
this situation from that of the early '70s.

After pyrotechnics separate the module from the rest of the vehicle, a
small motor can be used to build separation (-51L showed that no motor
at all is needed). Then instead of a giant parachute designed to give
the escape module a soft landing, all that is needed is a
stabilization chute system that slows the module down enough for the
crew to bail out of (no escape pole needed because the wings are long
gone).

I'm not sure that pyrotechnics to separate the crew module from the rest of
the vehicle would go over so well, but that's just a hunch. The idea doesn't
seem so bad given that the crew module had in the case of 51-L separated
from the fuselage, but in the case of Columbia, do we know? In practice, it
might not be so easy to build.

The strongest evidence available to the general public that Columbia's
crew module remained intact for a significant period following the
structural failure of the left wing was the continued data following
LOS along with the reports of the human remains and other cockpit
items being found within the same general area. A color-coded map
showing where these items were found will paint a clear picture of
crew cabin integrity in relation to the rest of the debris field. It
seems clear that the cabin did eventually fail at a high mach number,
but that it held together for a relatively long time. Given a
hypersonic drogue system for stabilization along with a minimal
thermal protection design, I expect that the crew cabin would have
brought Columbia's crew safely down to an energy level where a bailout
attempt would have been survivable.

I maintain that such a design was easily attainable with 1970's
technology. As far as pyrotechnics for cabin separation, such systems
had already been designed, tested, and used operationally in aircraft
such as the F-111 and the B-1A. My understanding is that upon
initiation, there are strips of shaped charges that cut the cabin away
from the fuselage and that there are pyrotechnic guillotines that
cleanly cut the wire bundles and other plumbing liberating the cabin
from the rest of the vehicle. Notice that the B-1A was a
Rockwell-designed vehicle. It's not hard to imagine a scene from
1971/72 where these Rockwell engineers responsible for designing crew
escape were arguing fervently how it is inexcusable to *not* have a
way out for shuttle astronauts. I expect that there are many within
NASA who had demanded it.

As far as culpability of those with oversight obligation, the link to
a report was posted back on Jan XX. See discussion from the archives:

http://tinyurl.com/md4q

http://groups.google.com/groups?hl=e...ing.google.com

It was the job of those on the ASAP to call a time out whenever they
saw NASA making unwise decisions. Designing the shuttle without a
crew escape module has proven itself time and again to have been a
fatal decision.

Today NASA wants to design in a crew escape probability of 0.99. Back
in the '70s, the decision was to give them a cumulative hope of ZERo.


~ CT