'Challenger' Survival

[James Oberg]

Sorry I wasn't clear. My supposition is that the Challenger crew, which
survived vehicle breakup but lost consciousness at altitude, could have
remained conscious inside the ACES/LES full pressure suits worn on Columbia.
The rotation rate of the crew cabin was no more than 3-4 RPM, I recall from
pictures -- probably not high-enough rotational G-forces to immobilize crew.
There was both the middeck side hatch and the overhead aft left window,
designed to open with a lever tool (for post landing egress). There was also
the airlock. Assuming the crew waited until below 40,000 feet, and the crew
module began stabilizing nose-down, the aero forces past both side and top
hatches might have been tough -- and there might not have been time to open
both airlock hatches. But anybody getting out would have been clear of
nearby debris (unlike the Columbia case) and 'home free' -- if they had the
kind of suit that was later adopted.

The crew systems training documents used throughout the 1990s explicitly
described the chances of an LES/ACES-equipped crewmember exiting a crew
cabin during 'uncontrolled flight', NOT just straight-and-level. I cited
this in an MSNBC.com article.

[Jon Berndt]

"James Oberg" > wrote in message
>
> Sorry I wasn't clear. My supposition is that the Challenger crew, which
> survived vehicle breakup but lost consciousness at altitude, could have

I may disagree with your supposition. After reviewing the videos from the
various camera angles it seems that the initial breakup process was pretty
rigorous. Quite a bit of the actual forward fuselage breakup can be seen
and there is some tumbling of the crew cabin that IIRC exceeds 3-4 rpm. I'm
not sure what the deceleration magnitude was, but the vector was constantly
changing at what must have seemed like a random function. That's an awful
lot of neck snapping, head-banging motions going on inside. Perhaps not
enough to immobilize them, per se, but I imagine with the varying
acceleration vector they would not have been coordinated enough to be able
to move anywhere without making things worse. If the cabin had stabilized -
say by a drogue - different story altogether.

Jon

If the crew did die from lack of O2, that was the easiest and most painless
possible way to die as anyone who has been through the Air Force High
Altitude Chamber course can attest. The danger you are trained to recognize
is the total lack of discomfort, bordering on euphoria just before you go
unconscious, when the air you are breathing is too thin. There is no choking
or sense of gasping for air at all, contrary to popular belief.

"James Oberg" > wrote in message
.. .
|
| Sorry I wasn't clear. My supposition is that the Challenger crew, which
| survived vehicle breakup but lost consciousness at altitude, could have
| remained conscious inside the ACES/LES full pressure suits worn on
Columbia.

[OM]

On Mon, 14 Jul 2003 22:54:48 GMT, "James Oberg"
> wrote:

>Sorry I wasn't clear. My supposition is that the Challenger crew, which
>survived vehicle breakup but lost consciousness at altitude, could have
>remained conscious inside the ACES/LES full pressure suits worn on Columbia.

....Nobody's arguing against this. What the question is, Jim, is
whether or not seven people could have bailed out of a tumbling crew
cabin that, while tumbling at 3-6 RPM, probably wasn't tumbing along
one main axis.

Of course, had they been able to bail out, with our luck we'd have
found that one or more couldn't swim, and...


OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr

[Jon Berndt]

"Charleston" > wrote in message news:M1JQa.16042

> "Jon Berndt" > wrote in message

> > I may disagree with your supposition. After reviewing the videos from
the
> > various camera angles it seems that the initial breakup process was
pretty
> > rigorous. Quite a bit of the actual forward fuselage breakup can be
seen
> > and there is some tumbling of the crew cabin that IIRC exceeds 3-4 rpm.
I'm
> > not sure what the deceleration magnitude was, but the vector was
constantly
> > changing at what must have seemed like a random function. That's an
awful
> > lot of neck snapping, head-banging motions going on inside. Perhaps not
> > enough to immobilize them, per se, but I imagine with the varying
> > acceleration vector they would not have been coordinated enough to be
able
> > to move anywhere without making things worse. If the cabin had
stabilized -
> > say by a drogue - different story altogether.
>
> Sigh.

"Sigh", as in,

"How unfortunate that nobody prepared for the possibility that there would
be a potentially survivable crew cabin separation above 45,000 feet"

or, as in

<exasperated disagreement>

:-)

Jon

[Joe D.]

"Mary Shafer" > wrote in message ...
> On Mon, 14 Jul 2003 22:54:48 GMT, "James Oberg"
> > wrote:
>
> >
> > Sorry I wasn't clear. My supposition is that the Challenger crew, which
> > survived vehicle breakup but lost consciousness at altitude, could have
> > remained conscious inside the ACES/LES full pressure suits worn on Columbia.
>
> You've overlooked g-LOC, though.
>
> > The rotation rate of the crew cabin was no more than 3-4 RPM, I recall from
> > pictures -- probably not high-enough rotational G-forces to immobilize crew.
>
> It's not just g level, but also onset rate.
>
> I can understand your reason for hoping, but there are a lot of ways
> to die in an airplane, particularly when it's tumbling. Flail,
> aversion, pressure-suit malfunction, etc.
>
It's hard to say. On the one hand, there are many accounts of bailouts
from tumbling, broken WWII bombers and fighters. So it's definitely
possible, and often in situations that seem impossible.

OTOH, there are numerous accounts where none of the crew got out,
despite superficially having a chance. I wonder if there are any statistics on
this? My guess is the % successfully exiting a tumbling, out-of-control B-17
(for example) were pretty low, and the spectacular survivals are exceptions.

In terms of bailout, a vaguely similar scenario to STS-51-L was the fatal X-2 flight of
Milburn G. Apt. After departing controlled flight, the X-2 nose jettisoned from the
fuselage, as designed. This was very roughly analogous to Challenger's cabin,
except the X-2 nose was specifically designed for that. Also it was much easier
for the pilot to separate from the nose. Despite this, Apt didn't make it, probably
because of temporary g-LOC, then ran out of time.

In the X-2 case I think the instrumentation showed very high G forces. What do
we know about the Challenger crew cabin G-forces? Did the Rodgers Commission
mention this?

If the scenario discussed is ACES/LES suits on Challenger STS-51-L (and that alone),
it seems pretty unlikely they'd make it out. Wasn't it after 51-L that a
pyrotechnically jettisonable hatch was added? Maybe if they had this on 51-L
there'd be a slightly greater chance.

-- Joe D.

[Paul Becker]

"Joe D." > wrote in message
...
> In the X-2 case I think the instrumentation showed very high G forces.
What do
> we know about the Challenger crew cabin G-forces? Did the Rodgers
Commission
> mention this?

It mentions at least one PEAP being activated, and I've read at least one
source in the past that said it was Michael Smith's, activated by Judith
Resnik (speculation?). The question becomes when did this activation occur?
Certainly the G-forces were low enough at some point for someone's arm to be
raised to reach a knob and rotate it, and this clearly had to have happened
before the supposed LOC.

[Reed Riddle]

In article . net>,
"Paul Becker" > wrote:

> "Joe D." > wrote in message
> ...
> > In the X-2 case I think the instrumentation showed very high G forces.
> What do
> > we know about the Challenger crew cabin G-forces? Did the Rodgers
> Commission
> > mention this?
>
> It mentions at least one PEAP being activated, and I've read at least one
> source in the past that said it was Michael Smith's, activated by Judith
> Resnik (speculation?). The question becomes when did this activation occur?
> Certainly the G-forces were low enough at some point for someone's arm to be
> raised to reach a knob and rotate it, and this clearly had to have happened
> before the supposed LOC.


At least 3 of 7 were activated, IIRC. They presumed that Resnik
activated Smith's, just based on positions and activities of the crew.
Also, Scobee's was not activated, while the fourth upper deck PEAP
(Onizuka, I think) was activated, as well as Resnik's. I don't recall
if they determined if PEAPs were activated on the middeck.

It also was a good story that Resnik reached up and turned Smith's on, a
last bit of heroism before they went unconscious due to lack of pressure.

If the Challenger crew was wearing the suits they wear now, they would
have retained consciousness without a doubt. I seem to recall that the
issue of tumbling and G forces was looked at, and they thought it was
possibly survivable (i.e. the crew wouldn't pass out from the Gs or
tumbling motion). It wouldn't have been easy by any stretch, but at
least some of them might have been able to get out with the new
equipment.

No chance for the Columbia crew though...no way you're going to design
an escape system for those conditions. And, sheesh, read the CAIB
report...Columbia was basically flying with an internally collapsed
wing, missing both upper and lower TPS covering, for around 300 seconds
during the most intense portion of the reentry! I wonder how close they
came to getting down lower, where they could have bailed out.....

Reed

--
Dr. Reed L. Riddle, Assoc. Dir., Whole Earth Telescope Operations
Iowa State University Department of Physics & Astronomy
Homepage: http://www3.iitap.iastate.edu/~riddle/
Remove "DAMN SPAM" from my email address to reply.....

"This life has been a test. If it had been an actual life, you would
have received actual instructions on where to go and what to do."
-- Angela Chase, "My so-called life"

[Mary Shafer]

On Tue, 15 Jul 2003 03:14:24 GMT, "James Oberg"
> wrote:

> Mary, can you follow up and elaborate on these themes, please?
>
>
>
> "Mary Shafer" > wrote in message
> ...
> > On Mon, 14 Jul 2003 22:54:48 GMT, "James Oberg"
> > > wrote:
> >
> > >
> > > Sorry I wasn't clear. My supposition is that the Challenger crew, which
> > > survived vehicle breakup but lost consciousness at altitude, could have
> > > remained conscious inside the ACES/LES full pressure suits worn on
> Columbia.
> >
> > You've overlooked g-LOC, though.

This is g-induced loss of consciousness. G tolerance is a function of
anticipation, recent experience, g suit, physical condition, sex
(women are more tolerant), fatigue, general health, and other factors.
For a well-conditioned, healthy pilot who has flown high-g maneuvers
recently, who is good at the straining maneuver, who isn't tired, who
knows the straining maneuver, etc, the maximum g level that can be
tolerated without LOC, in a smooth, relatively slow input maneuver, is
about 9 g.

For the backseater ditto, the maximum level is probably 1 or 2 g
lower. This is because the backseater isn't making the input and
can't anticipate it and start straining at the beginning of the input.

On the other hand, a tired, out-of-condition pilot who hasn't flown at
high g recently, isn't good at the straining maneuver, and is a bit
dehydrated probably can't pull much more than 7 g without LOC.

Gray-out happens 2 or 3 g lower than LOC as a rule.

Forgive me all the qualifiers, but they do matter.

To give you a concrete example of the value of anticipation, one of
our test pilots was letting his backseater, an engineer and
experienced pilot, fly the F-18. They were maneuvering, I think as
part of the PMCF cards. The backseater initiated an aft-stick input
and the resulting g blacked out the test pilot briefly. This was the
classic "high-g" pilot, good condition, g suit, experience, etc, but,
because he was unable to anticipate the maneuver he couldn't keep from
losing consciousness. The backseater had a little gray-out, but that
was all (however, remember the reduced moment arm in the aft cockpit,
which was probably a factor). This wasn't a 9-g maneuver, more like 7
in the front seat.

Also, recovery from g-LOC isn't instantaneous; it takes a while for
the body to get O2-rich blood back to the brain and for the brain to
do an IPL. Even if the g level goes back down right away, the pilot
is going to take a while to recover and will be a little twitchy at
first. Literally, not figuratively. It's not a full-up tonic-clonic
seizure by any means, but there's a definite neurological effect.

> > > The rotation rate of the crew cabin was no more than 3-4 RPM, I recall
> from
> > > pictures -- probably not high-enough rotational G-forces to immobilize
> crew.
> >
> > It's not just g level, but also onset rate.

In a word, F-20s.

Northrop lost two F-20s doing demo routines that should have been
safe, having been flown many times before, but there was no reason
known for the losses--nothing mechanical, nothing from the pilot,
nothing. The airplanes just fell out of the sky.

Finally, after a great deal of research, the aeromedical folks figured
out it was g-onset-rate. That is, the rate at which the g is applied
initially can be lower than the level the pilot can tolerate, but
because it happens so quickly, the body just can't keep enough blood
at the brain. I think the big clue was that the other pilots had been
graying out earlier than they expected, doing the routine.

The old g-LOC chart, with g vs time, had a very short, linearly sloped
ramp at the beginning, topping out at 9 g. Everything above that line
was g-LOC, everything below that line and above a parallel line about
3 g down was grey-out or other impairment, and everything below the
bottom line was no problem. It turns out the original slope of the
ramp was wrong and it was possible for a pilot to snatch himself into
LOC at g levels far below those ever thought to be dangerous. (You
snatch an airplane by making a big, fast nose-up input.)

As I recall, the initial perturbation of the Challenger crew cabin was
fairly high, like 20 g. High onset rate, no anticipation, no g suit.

> > I can understand your reason for hoping, but there are a lot of ways
> > to die in an airplane, particularly when it's tumbling. Flail,
> > aversion, pressure-suit malfunction, etc.

That should have been "avulsion", not "aversion". Spell checkers
aren't very good at some of this.

I was actually thinking of the Columbia accident more than the
Challenger accident, but g can cause some of these. However, these
happen most commonly when aircrew are exposed to the airflow suddenly,
as in an ejection.

Flail is the tendency of unsupported extremities, including the head,
to be driven to very peculiar and unnatural positions relative to the
torso and can include amputation, massive joint damage, and torn
muscles and ligaments, in descending order of concern. High g levels
can cause this, as can wind blast. Shock, blood loss, and pain can
cause unconsciousness.

Avulsion is peeling away the flesh from the body, frequently beginning
at a natural orifice like the eyes or mouth. Wind blast, not g,
probably. Same effects as flail, only more so.

Pressure suit malfunction is just what it sounds like. A mis-mated
helmet, for example, can cause enough leakage to leave the aircrew
unprotected. Of course, both g and blast can pull an insecurely
fastened pressure suit apart. Striking a hard surface with enough
force can crack a visor.

Anything wind blast can do, really hot air, at high speed, can do
better. And more. Pressure suits are not designed for hypersonic
flight without the protection of a vehicle.

In the case of Challenger, the integrity of the pressure vessel is
also an issue. It doesn't take much to crack the vessel open and this
will let all the air out. The PEAP(S?) isn't a self-contained
breathing apparatus and it would be totally ineffective at that
pressure altitude. It would also be exhausted long before the crew
cabin reached an altitude with enough O2 to sustain life.

These are just some of the ways to die in aircraft. How about making
a successful ejection at over Mach 3, after the drone you're launching
takes the left rudder off your modified A-12, and drowning? Or having
your throat cut by a shard of the canopy after a high-speed bird
strike? Or being cooked (well-done in ten or fifteen seconds,
unconscious in a lot fewer) by the hot air from the engine bleed air
duct that runs right by the aft cockpit of the F-4?

Flying in high-performance aircraft is dangerous. The Orbiter is just
one such.

Mary

--
Mary Shafer Retired aerospace research engineer

"A MiG at your six is better than no MiG at all."
Anonymous US fighter pilot

[John Maxson]

Mary Shafer > wrote in message
...
> On Tue, 15 Jul 2003 03:14:24 GMT, "James Oberg"
> > wrote:
>
> > Mary, can you follow up and elaborate on these themes, please?

<snipped explanation and relevance to 51-L of g-LOC and g-onset-rate>

Thanks for sharing your extensive insight here, Mary. It meshes
with my gut feeling on the topic and reinforces my thinking.

> It turns out the original slope of the ramp was wrong and it was
> possible for a pilot to snatch himself into LOC at g levels far below
> those ever thought to be dangerous. (You snatch an airplane by
> making a big, fast nose-up input.)

I assume you agree that if the 51-L forward fuselage nosed-up (flying
inverted as it was), its top immediately met increased air resistance.

> As I recall, the initial perturbation of the Challenger crew cabin was
> fairly high, like 20 g. High onset rate, no anticipation, no g suit.

Assuming the cabin nosed-up, would that be enough to help explain
why so little was recovered from the *top* of the forward fuselage
(relative to the bottom and sides)?

http://history.nasa.gov/rogersrep/v3o387a.htm

If not, could the forward fuselage perhaps have struck the ocean
top-first, nose-forward?

<snipped fine explanation of flail, avulsion, etc., with relevance to 51-L>

--
John Thomas Maxson, Retired Engineer (Aerospace)
Author, The Betrayal of Mission 51-L (www.mission51l.com)

[Charleston]

"Mary Shafer" > wrote in message
...
> On Tue, 15 Jul 2003 03:14:24 GMT, "James Oberg"
> > wrote:
> > Mary, can you follow up and elaborate on these themes, please?
> > "Mary Shafer" > wrote in message
> > ...
> > > On Mon, 14 Jul 2003 22:54:48 GMT, "James Oberg"
> > > > wrote:
> > >
> > > >
> > > > Sorry I wasn't clear. My supposition is that the Challenger crew,
which
> > > > survived vehicle breakup but lost consciousness at altitude, could
have
> > > > remained conscious inside the ACES/LES full pressure suits worn on
> > Columbia.
> > >
> > > You've overlooked g-LOC, though.

I don't think so. We know that at least three crew members activated their
Personnel Emergency Air Packs. They could not have done this while
unconscious. They could not have done it during the very brief 12-20g
period they were exposed to at break-up. They could only do so if the crew
compartment was in a relatively stable tumble. Afterall, it happened so
quickly it had to be a little disorienting.

> This is g-induced loss of consciousness. G tolerance is a function of
> anticipation, recent experience, g suit, physical condition, sex
> (women are more tolerant), fatigue, general health, and other factors.
> For a well-conditioned, healthy pilot who has flown high-g maneuvers
> recently, who is good at the straining maneuver, who isn't tired, who
> knows the straining maneuver, etc, the maximum g level that can be
> tolerated without LOC, in a smooth, relatively slow input maneuver, is
> about 9 g.

Well they were not expecting it, I'll agree with that.

<snip interesting examples>

> Also, recovery from g-LOC isn't instantaneous; it takes a while for
> the body to get O2-rich blood back to the brain and for the brain to
> do an IPL. Even if the g level goes back down right away, the pilot
> is going to take a while to recover and will be a little twitchy at
> first. Literally, not figuratively. It's not a full-up tonic-clonic
> seizure by any means, but there's a definite neurological effect.

Thus in the case of Challenger G-Loc did not likely occur, perhaps because
the duration of high gs was so short.

<snip>

> In the case of Challenger, the integrity of the pressure vessel is
> also an issue. It doesn't take much to crack the vessel open and this
> will let all the air out. The PEAP(S?) isn't a self-contained
> breathing apparatus and it would be totally ineffective at that
> pressure altitude.

It is a SCBA with six minutes of breathing air not O2. So indeed if the
pressure vessel was seriously compromised the PEAP would have provided no
help.

It would also be exhausted long before the crew
> cabin reached an altitude with enough O2 to sustain life.

There was 1/8 to 1/4 of the air content left in each PEAP at water impact.
The PEAP contains two 2100 psi air bottles connected to a pressure regulator
with a pressure bypass check valve that allows orbiter O2 (100 psi) to pass
through the PEAP when it is hooked up to the Launch and Entry Helmet (LEH).
When the crewmember activates the PEAP the orbiter O2 still flows into the
LEH, until the astronaut has unhooked the PEAP from its seat attachment and
hooked it up to the flight suit carabiner. Then the astronaut hits the
quick disconnect and exits the crew compartment (launch pad or after landing
only). In the alternative when the O2 pressure is lower than the PEAP air
pressure at the regulator (70 psi) you get PEAP air to the LEH Challenger
accident). I think I got that right.

<snip>

> Flying in high-performance aircraft is dangerous. The Orbiter is just
> one such.

Except that most high-performance aircraft have an escape system that gives
the pilot an escape opportunity which is better than what the Challenger
crew got and the Space Shuttle is orders of magnitude more dangerous than
most high-performance jet aircraft. As with everything there are
exceptions.

--

Daniel
Mount Charleston, not Charleston, SC

[Derek Lyons]

Reed Riddle > wrote:
>It also was a good story that Resnik reached up and turned Smith's on, a
>last bit of heroism before they went unconscious due to lack of pressure.

Such actions can be performed without full consciousness being
present, especially in situations where the action is embedded in the
muscle memory of the person performing the action.

During a casualty drill, there were numerous times when I'd go from a
dead sleep in my bunk to being completely awake, alert, aware, and on
station, with *no* conscious memory of how I got there. Adrenaline,
reflexes, and the subconscious did the work while the conscious mind
was spinning up.

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.

[Greg D. Moore \(Strider\)]

"Derek Lyons" > wrote in message
...
> Reed Riddle > wrote:
> >It also was a good story that Resnik reached up and turned Smith's on, a
> >last bit of heroism before they went unconscious due to lack of pressure.
>
> Such actions can be performed without full consciousness being
> present, especially in situations where the action is embedded in the
> muscle memory of the person performing the action.
>
> During a casualty drill, there were numerous times when I'd go from a
> dead sleep in my bunk to being completely awake, alert, aware, and on
> station, with *no* conscious memory of how I got there. Adrenaline,
> reflexes, and the subconscious did the work while the conscious mind
> was spinning up.

Did that once when I was on beeper duty and the phone rang. Had the phone
in hand and was 1/2-way down the stairs towards my computer before I was
actually concious of what I was doing. But the "get out of bed, grab the
phone, answer it, acknowledge the problem" was all auto-polit.

>
> 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.

[Derek Lyons]

"Greg D. Moore \(Strider\)" > wrote:
>
>"Derek Lyons" > wrote in message
>
>> During a casualty drill, there were numerous times when I'd go from a
>> dead sleep in my bunk to being completely awake, alert, aware, and on
>> station, with *no* conscious memory of how I got there. Adrenaline,
>> reflexes, and the subconscious did the work while the conscious mind
>> was spinning up.
>
>Did that once when I was on beeper duty and the phone rang. Had the phone
>in hand and was 1/2-way down the stairs towards my computer before I was
>actually concious of what I was doing. But the "get out of bed, grab the
>phone, answer it, acknowledge the problem" was all auto-polit.
>

Happens to a lot of folks, but it was beaten into us as it could make
the difference between life and death, literally. I imagine the same
holds true for astronauts.

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.