Pre-Columbia Criticism of NASA's Safety Culture in the late 1990's

"Hallerb" wrote ...

For everyone interested, you can check out the October Popular Science
article that covers space shuttle egress. See new thread at

. com

Sorry you are not allowed access to that arera. What error problem is this???

The error of using AOL for your newsreader SW?

Maybe the format

m

will work better for you or via Google as

http://www.google.com/groups?as_umsg... ng.google.com

From Derek:
(Stuf4) wrote:
What is at issue here (in or out of context) is escape from vehicles
capable of hypersonic spaceflight. When discussing crew escape from
the X-15 or shuttle, it is a misdirected criticism to cite subsonic
capsule performance of aircraft like the F-111.

There is no evidence that the problems with weight and controllability
that F-111 style capsules suffer from would not also apply to the
Shuttle/X-15. (In fact, given the greater enviromental effects,
there's every evidence that they's be *worse*.)

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Weight is definitely a problem with escape modules. Impact
attenuation bags often did not cushion the module sufficiently upon
impact. Crew members commonly suffered back injuries.

But if given the choice of having a broken back or being dead, I'll
take the wheelchair.

(And again, there's a lot to be said just for giving the crew *hope*
of survival.)

An escape module could very well have saved Mike Adams. Regarding the
shuttle, an escape module could very well have eliminated a number of
memorial names for high schools and parks and such across the country.

An unproven assumption on your part, without one shred of evidence.

Not that you are capable of knowing the difference anyhow.

I'll repost from that other thread:

_________

....October Popular Science cover story, "Get Out Now!" It has some
excellent info on shuttle escape:

http://www.popsci.com/popsci/aviatio...3779-4,00.html

Excerpt:

"The Challenger accident was eminently survivable," says Gutierrez,
pilot of STS 40 and commander of STS 59. "Had the Challenger crew had
ejection seats, they'd have been drinking beers at one of the bars in
Canaveral that evening." More provocatively, Gutierrez makes the same
claim for Columbia. "You put the [mid-deck] crew in a capsule in the
payload bay," he says. "The capsule would be statically and
dynamically stable." If the shuttle was determined unsafe for return,
the capsule would eject into space. A small retro-rocket would slow it
to a safe entry speed, "and they would ride that hummer to the
ground."
_________


I will grant that my statement goes unproven. But Sid has studied
this issue a lot more than I have. I give lots of weight to his
position that it can be done. In that article he says something to
the effect that the problem was solved in the '60s and that we can do
it even better with today's technology.

If anyone cares to refute this argument, I would be interested in
seeing something stronger than pointing to how some F-111 crew members
got broken backs after ejecting within the envelope of the escape
module.

Until convinced otherwise, I maintain the position that not having
given shuttle astronauts a way out was an inexcusable decision.

(And Mike Adams' wife, Freda, may feel similarly about X-15 design.)


~ CT

In article ,
(Stuf4) wrote:

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

"Controllability" is a combination of several things which in this case
can probably be boiled down to active manipulation of the escape
module's velocity vector - do you really want to make a tumbling,
supersonic impact into a mountain? Or would you rather stabilize the
module, preferably oriented in a statically-stable attitude, then try to
decelerate the module for a safe descent with impact at some
reasonably-survivable velocity?

BTW, any escape module that has any hope of preserving the lives within
it MUST be designed for some degree of control, even it it's only
passive control of attitude via fins or other aerosurfaces. "Tumbling"
most likely = "dead."

Weight is definitely a problem with escape modules. Impact
attenuation bags often did not cushion the module sufficiently upon
impact. Crew members commonly suffered back injuries.

But if given the choice of having a broken back or being dead, I'll
take the wheelchair.

You DO know, don't you, that broken backs often lead to death? Cervical
fractures are much worse than thoracic or lumbar fractures but they are
ALL serious and often permanently life-changing for the worse.

--
Herb Schaltegger, B.S., J.D.
Reformed Aerospace Engineer
"Heisenberg might have been here."
~ Anonymous

(Stuf4) wrote:

From Derek:
(Stuf4) wrote:
What is at issue here (in or out of context) is escape from vehicles
capable of hypersonic spaceflight. When discussing crew escape from
the X-15 or shuttle, it is a misdirected criticism to cite subsonic
capsule performance of aircraft like the F-111.

There is no evidence that the problems with weight and controllability
that F-111 style capsules suffer from would not also apply to the
Shuttle/X-15. (In fact, given the greater enviromental effects,
there's every evidence that they's be *worse*.)

I'm not aware of controllability problems experienced in any escape
module ejection

Studying the issue would help you greatly then.

(I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Both ejection seats and escape capsules have systems to *control* the
attitude of the seat/capsule.

(And again, there's a lot to be said just for giving the crew *hope*
of survival.)

Having been crew in just such a situation, we were quite aware of how
useless our escape provisions and systems were. They were not a
source of hope, but of amusement.

An escape module could very well have saved Mike Adams. Regarding the
shuttle, an escape module could very well have eliminated a number of
memorial names for high schools and parks and such across the country.

An unproven assumption on your part, without one shred of evidence.

Not that you are capable of knowing the difference anyhow.

I'll repost from that other thread:


pointless noise snipped

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.

(Stuf4) writes:

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Just because it doesn't have a "man in the loop" control system,
doesn't mean that there isn't one. You should read up on the state of
the art of e-seats.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.

From Jeff Findley:
(Stuf4) writes:

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Just because it doesn't have a "man in the loop" control system,
doesn't mean that there isn't one. You should read up on the state of
the art of e-seats.

Here is the statement that was being questioned:

"...the problems with weight and controllability that F-111 style
capsules suffer from..."

If anyone thinks that these egress systems being discussed had *any
type* of flight control system, I suggest that you check your facts.


Now, regarding a statement that it is *possible* to control such
systems, I would agree with that.


~ CT

(Stuf4) wrote:

From Jeff Findley:
(Stuf4) writes:

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Just because it doesn't have a "man in the loop" control system,
doesn't mean that there isn't one. You should read up on the state of
the art of e-seats.

Here is the statement that was being questioned:

"...the problems with weight and controllability that F-111 style
capsules suffer from..."

If anyone thinks that these egress systems being discussed had *any
type* of flight control system, I suggest that you check your facts.

And the facts show plainly that they do in fact have rather elaborate
flight control systems.

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.

From Herb Schaltegger:
(Stuf4) wrote:

I'm not aware of controllability problems experienced in any escape
module ejection (I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

"Controllability" is a combination of several things which in this case
can probably be boiled down to active manipulation of the escape
module's velocity vector - do you really want to make a tumbling,
supersonic impact into a mountain? Or would you rather stabilize the
module, preferably oriented in a statically-stable attitude, then try to
decelerate the module for a safe descent with impact at some
reasonably-survivable velocity?

You start off talking about manipulation of the velocity vector
(control) and then jump straight into stability issues that have
nothing to do with control. "Active manipulation of the escape
module's velocity vector" would qualify as control if these modules
had means to do so. But they do not. They are ballistic. (Much to
the regret of all those crew members whose ejection rockets vectored
their bodies straight into terra firma.)


Let's be clear about the distinction between the concepts of
_stability_ versus _control_:

The fundamental characteristic of control is an effort toward
manipulating a particular trajectory (how the value of some parameter
varies over time). Whether this is done with a blind open-loop or
with closed-loop error feedback, inputs are being made with some
trajectory as the goal.

Stability is a much more basic concept than control. Stability refers
to how well the status quo is maintained. If disturbance results in a
departure from the status quo, then the system is unstable. If there
is no departure, then the system is stable.

(More specific definitions sprout from these basic concepts.)

In a nutshell:

- Stability happens whether or not control is attempted.
- Control *cannot* happen without stability.


BTW, any escape module that has any hope of preserving the lives within
it MUST be designed for some degree of control, even it it's only
passive control of attitude via fins or other aerosurfaces. "Tumbling"
most likely = "dead."

(Here again, "control" is being used as a synonym for _stability_!)

Escape modules have been designed with no control because for the vast
majority of the cases they can do just fine with no control at all.

Stable - yes.
Control? - can do without.

(Consider the case of ICBMs. They get to the other side of the planet
on a _ballistic_ trajectory.)

Weight is definitely a problem with escape modules. Impact
attenuation bags often did not cushion the module sufficiently upon
impact. Crew members commonly suffered back injuries.

But if given the choice of having a broken back or being dead, I'll
take the wheelchair.

You DO know, don't you, that broken backs often lead to death? Cervical
fractures are much worse than thoracic or lumbar fractures but they are
ALL serious and often permanently life-changing for the worse.

Ideally, the crew module will be designed well enough for the crew to
walk away from it.


~ CT

From Derek:
(Stuf4) wrote:
What is at issue here (in or out of context) is escape from vehicles
capable of hypersonic spaceflight. When discussing crew escape from
the X-15 or shuttle, it is a misdirected criticism to cite subsonic
capsule performance of aircraft like the F-111.

There is no evidence that the problems with weight and controllability
that F-111 style capsules suffer from would not also apply to the
Shuttle/X-15. (In fact, given the greater enviromental effects,
there's every evidence that they's be *worse*.)

I'm not aware of controllability problems experienced in any escape
module ejection

Studying the issue would help you greatly then.

(I'm not even sure what is meant by this because they
aren't designed for controlled flight. As with ejection seats, once
you pull the handle you are just along for the ride).

Both ejection seats and escape capsules have systems to *control* the
attitude of the seat/capsule.

?

For the egress systems we've been discussing, you take whatever
attitude you get! (Perhaps what you meant was attitude _stability_,
which has been in use for a long time.)

As Jeff alludes to below, ejection seat design has ventured into the
realm of attitude control. The earliest test that I'm aware of
happened at China Lake back in the late '70s, with the program getting
cancelled in the early '80s.

I seem to remember a dramatic photo of such a system making the cover
of AvWeek in the early '90s (similar to the photo here at
http://www.nawcwpns.navy.mil/clmf/pro-ject.html). But this pursuit
has panned out as a dead end. Quick separation is a goal that
conflicts with changing that vector. And the human spine takes severe
accelerations much better in one axis rather than twisting to the
vertical.

So far the optimized solution has shifted the focus toward getting the
parachute out more quickly. To this day I am not aware of any
operational aircraft with ejection seats that use attitude control.

(And again, there's a lot to be said just for giving the crew *hope*
of survival.)

Having been crew in just such a situation, we were quite aware of how
useless our escape provisions and systems were. They were not a
source of hope, but of amusement.

(If this is about submarine egress, that PopSci article had some
interesting info on that topic as well.)


~ CT

"Stuf4" wrote in message

(If this is about submarine egress, that PopSci article had some
interesting info on that topic as well.)

~ CT

I've come to regard Popular Science (and Popular Mechanics) with a pretty
big degree of skepticism, based on what I've seen in occasional perusings in
the supermarket.

I'm afraid that the shuttle can only be made safer by attending to
prevention. This is not a big deal. (Hint: alpha=2 - debris hits SRB skirt;
alpha=4 - debris hits RCC ... debris sources also removed ... on-orbit
inspection capability added, etc.). With enough attention to detail, I think
shuttle reliability can be kept above what most would consider acceptable
for the near term. A CTV with more latitude in abort/escape capabilities
needs to be fielded ASAP. I think that for shuttle, the dedicated pursuit
of prevention is all that can be done, in lieu of an escape module concept
that could very well end up adding failure modes with no real hope of adding
actual survivability and reducing payload capacity to the point of making it
useless.

Jon