Conference 7.286::space

    I saw something on the news yesterday which suggested someone was
    trying to figure out a way to make the entire crew cabin an escape
    module of some sort.  They were looking at ways to put parachutes,
    etc., on it an allowing the cabin to separate from the shuttle in
    an emergency.  However, since there is no spare room in the shuttle
    it would be a several year redesign effort to work out the system.
    
    I think it was Richard Truly who said such a system might have been
    able to save lives in the case of the Challenger explosion.  Even
    though the crew wouldn't have had time to initiate an escape sequence
    if the crew module had parachutes some of them might have lived.
    

    A lot of this talk came up when it was discovered that the crew
    cabin may have survived intact until impact with the water. This
    led to speculation about allowing the the cabin to seperate in an
    emergency.
    
    gary

    I heard something on "the news" that one or more of these ideas
    wouldn't work if the explosion was just a little lower or higher
    in altitude.  Whoever said that didn't seem to be impressed in
    making radical changes for an event unlikely to happen with just
    those exact conditions again.
    
    (Sorry for being vague, it was a day or two ago I heard this.)
    
    Charlie

    Since it seems that at least some of the crew were concious long
    enough to turn on their O2 and don the mask, a "command ejection"
    sequence might have saved the whole crew. A command ejection sequence
    in a modern jet fighter is one where no matter which crew member
    initiate the ejection the entire crew is ejected in the proper
    sequence. Proper sequence is required to avoid injury to the other
    members of the crew, ie being burned by the seat rocket.
    
    I saw the somments that these would have only worked for this one
    rare type of explosion, of course this explosion could never have
    happened either. I don't think that these guys really know for sure
    and it seems stupid to gamble the crew's life on an assumption that
    is not testable.
    
    dave

Re .3:

I've also heard claims in the media that there was only a narrow altitude
window during a launch where the crew could be saved.  I'm not impressed
by them in the least.  I suspect that they were generated by people trying
to rationalize participation in decisions to omit orbiter escape systems by
claiming that they are ineffective in a few accident scenarios.  And/or by
the media trying for emotional leverage by pandering to conjectures
about "what if we only had done this...".

If it means the entire crew has to be wearing oxygen masks and/or
relatively cheap flight suits (unsuitable for EVA in orbit), then so
be it.  If it means the commander and pilot have to be in real space suits
to allow them to command after a catastrophic loss of cabin pressure,
then fine, do it.  If it means that some accidents would result in possible
anoxia for the back-seat crew members, or potentially non-survivable
decelerations because of low-altitude parachute deployment from the
crew module, so what.  The people that don't want the systems can volunteer
to go up with cheap seat belts and no masks once the shuttle flys again
to demonstrate how futile it all is.

The trouble is, if it really takes a long time and a lot of money to
retrofit the remaining orbiters with escape systems, then the program will
be over before they are done.  And that may not be because the TAV has
superseded the shuttle, either.
				/AHM

      The issue of escape systems comes down to one of weight vs 
    reliability. The narrow window is due to the fact that once you
    get above a certain speed you would need a heat shield as well
    as a pressure suit or capsule to survive.
    
      If you believe that the shuttle can not be made reliable and you
    can afford the weight you could make the entire crew compartment
    an escape capsule with heat shield, control system, etc. (i.e.
    something like an Apollo command module). This would save the
    crew from most situations.
    
      By the way, according to AWST, NASA is considering an escape
    system for the space station based on Apollo technology.
    
      If you believe that the shuttle can be made reliable then you
    save the weight and try to land if there is a problem. This is
    the aproach taken by the airlines. There have been several air
    disasters that might not have been as bad if DC-10s, 727s, etc
    had escape systems but they are still not put in place and
    probably shouldn't be.
    
      George

    Note 177.* contains the earlier discussion on this subject.
    Interesting reading in light of the current news.
    
    						-Dave