spain@alliant.UUCP (11/11/87)
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
marshek@ut-ngp.UUCP (/MAt) (11/12/87)
In article <843@alliant.Alliant.COM>, spain@alliant.Alliant.COM (Dave Spain) writes:
:
: 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
PLEASE EMAIL THE RESPONSES TO ME TOO...henry@utzoo.UUCP (Henry Spencer) (11/16/87)
> 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? 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
petej@phred.UUCP (Pete Jarvis) (11/18/87)
Dave Spain--> There will not be ejection seats installed in the Shuttles. 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@utzoo.UUCP (Henry Spencer) (11/22/87)
> ...It probably will not be incorporated on the first few flights....
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.
--
Those who do not understand Unix are | Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly. | {allegra,ihnp4,decvax,utai}!utzoo!henrytim@ism780c.UUCP (11/25/87)
In article <1842@phred.UUCP> petej@phred.UUCP (Pete Jarvis) writes:
< 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 tim@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@utzoo.UUCP (Henry Spencer) (11/29/87)
> 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. ... is there anything wrong with it at a > 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. -- Those who do not understand Unix are | Henry Spencer @ U of Toronto Zoology condemned to reinvent it, poorly. | {allegra,ihnp4,decvax,utai}!utzoo!henry