Crew Escape Mechanisms
sp...@alliant.uucp
Can someone out there fill me in on what modifications have been made to
the shuttle and launch proceedures to enhance crew safety during ascent?
Am I correct in assuming that ejection seats have been added to the flight-
deck seats? What about the people in the mid-deck?
Has the criterion for acceptable weather been updated? And if so what is it?
While I'm at it, has anything new been added to enhance saftey during re-entry?
Forgive me if this has been covered before as I have been away from the net
for awhile. If you prefer you can E-mail a response.
Dave Spain
spain@alliant
/MAt
:
: Can someone out there fill me in on what modifications have been made to
:
: Dave Spain
: spain@alliant
PLEASE EMAIL THE RESPONSES TO ME TOO...
Henry Spencer
> the shuttle and launch proceedures to enhance crew safety during ascent?
A lot of little things. Fixing the SRBs, adding a locking system to the
main propellant valves (having one of them slam shut would be, um, nasty),
and generally planning to fly less demanding missions at lower weights are
the biggies.
> Am I correct in assuming that ejection seats have been added to the flight-
> deck seats? What about the people in the mid-deck?
No, no ejection seats. They take up a lot of space, they are heavy, and
there is no obvious way to provide them for the mid-deck crew. They also
are effective over only a fairly limited speed and altitude range. What
is being done is to add a simple escape system -- details not yet fully
settled -- to allow bailing out safely in gliding flight (i.e. if you get
safely separated from the SRBs and the tank but cannot find a runway; the
orbiter is too fragile for a belly landing or ditching), which is not now
possible because (a) the hatch is not designed to be opened in the air,
and (b) just jumping out involves a high probability of hitting the wing.
> Has the criterion for acceptable weather been updated? And if so what is it?
They will undoubtedly be rather fussier about this, but I don't know details.
> While I'm at it, has anything new been added to enhance saftey during re-entry?
Not that I know of offhand. Re-entry is the easy part, actually.
--
Those who do not understand Unix are | Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly. | {allegra,ihnp4,decvax,utai}!utzoo!henry
Pete Jarvis
What they are working on is a rocket escape system that would work during
a controlled glide back to Earth in case they had to do an abort from the
stack after the SRB's have burned out, but before reaching orbit. There
is no possible escape during the first 2 minutes of ascent because of the
loads on the vehicle. The rocket escape system, in short, will propel each
Astronaut out the side hatch in a "controlled" emergency. But this will add
weight and storage problems to the Shuttle. It probably will not be
incorporated on the first few flights. In fact, I've not heard any more
about this for a long time now. Don't know for sure whether they will have
such a system.
Peter Jarvis - Physio-Control
Henry Spencer
This has not been decided yet. There is a possibility that it will go in
for the very next flight, although the schedule is distinctly tight if
STS-26 is to go up in June.
t...@ism780c.uucp
< stack after the SRB's have burned out, but before reaching orbit. There
< is no possible escape during the first 2 minutes of ascent because of the
< loads on the vehicle. The rocket escape system, in short, will propel each
Since the Challenger crew survived the explosion, doesn't that indicate
that there is a possible escape mechanism for the first two minutes? For
instance, put a parachute on the crew compartment, and when there is an
emergency, you blow up the external tank. The crew compartment then
descends back to the ocean.
Ok, this is a little crazy, but is there anything wrong with it at a
fundamental level?
By the way, did NASA ever release the autopsy reports? How many crew
members did survive the explosion? How serious were their injuries
before they hit the water?
--
Tim Smith, Knowledgian t...@ism780c.isc.com
"and if I ever lose my eyes, if my colours all run dry,
yes, if I ever lose my eyes, oh if...
I won't have to cry no more"
Henry Spencer
> that there is a possible escape mechanism for the first two minutes? For
> instance, put a parachute on the crew compartment, and when there is an
> emergency, you blow up the external tank. The crew compartment then
> fundamental level?
The parachute would be big and heavy, unfortunately, since the crew
compartment weighs a lot. Worse, could you rely on the parachute being
intact after violent disintegration of the orbiter? More controlled
versions of this idea have been looked at; the only deep, fundamental
problem is that they add a lot of complexity and weight, plus safety
problems of their own (there is no such thing as an escape system which
will never fire accidentally).
On a smaller scale, invididual parachutes, oxygen, and pressure suits might
have kept the Challenger astronauts alive, given that they survived the
breakup. Parachutes are definitely going to be aboard henceforth, as an
alternative to unsurvivable things like ditching or belly-landing an
orbiter. Oxygen and pressure suits are being looked at quite seriously.
> By the way, did NASA ever release the autopsy reports? How many crew
> members did survive the explosion? How serious were their injuries
> before they hit the water?
I'm not sure they released the actual autopsy reports; they did release
Joe Kerwin's medical report, which summarized the results from autopsies
and other forensic work. (Remember that, to quote somebody or other,
"we're talking about remains, not bodies" -- the crew cabin wasn't found
right away.) It is probable that the entire crew survived the breakup
without crippling injury; the human body is pretty tough. Certainly some
of them were alive and conscious for a few seconds afterward. If the cabin
held pressure -- superficially unlikely, but the forensic people were not
able to find out for sure -- they could have been alive and conscious
until water impact.