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From: peterb@pbear.UUCP
Newsgroups: net.columbia
Subject: Re: Challenger disaster
Message-ID: <900005@pbear.UUCP>
Date: Wed, 5-Feb-86 23:42:00 EST
Article-I.D.: pbear.900005
Posted: Wed Feb  5 23:42:00 1986
Date-Received: Tue, 11-Feb-86 07:22:03 EST
References: <787@decwrl.UUCP>
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Nf-ID: #R:decwrl:-78700:pbear:900005:000:3373
Nf-From: pbear!peterb    Feb  5 23:42:00 1986


>      .....         Think, folks (and I hope the 'Powers' in their
>finite wisdom do, too) -- ejection seats on fighter aircraft depend on the
>fact that the canopy can be blown clear first (and a few pilots have died
>when it wasn't).  Is it feasible to put a removable canopy in a shuttle???
>Or are we going to eject them through the roof?  There is no smiley here
>because too many people -- no doubt uninformed people -- have phrased the
>question seriously.
>
>Barb

Not only that Barb, some people think that if the ejection seats were in the
Challenger then the occupants would had a better chance of surviving.

This is impossible. First if there was enough time for the astronauts to
eject, they would have been become crispy critters when their ejection seats
are fried by the intense heat of the blast, or riddled by millions of white
hot pieces of shrapnel. Ok, if they had about 15 seconds time they would be
out of the danger zone, but problems in the shuttle turn sour far faster
than that...

Second, I don't know about you, but I would NEVER eject from an airplane
at Mach 3+ (the shuttle was moving at 2900 feet per second, or 1977 mph).
The wind shear would rip your hide apart. I quote an excerpt from Tom
Wolfe's _The_Right_Stuff_ top of page 17:

	   In time the Navy would compile statistics showing that
	for a career Navy pilot, i.e.  one who intended  to  keep
	flying  for twenty years as (Peter) Conrad did, there was
	a  23  percent  probability  that  he  would  die  in  an
	aircraft  accident.   This  did  not  even include combat
	deaths, since the military  did  not  classify  death  in
	combat  as  accidental.   Furthermore, there was a better
	than even chance, a 56 percent probability, to be  exact,
	that  at  some  point  a  career Navy pilot would have to
	eject from his aircraft  and  attempt  to  come  down  by
	parachute.   In  the  era of jet fighters, ejection meant
	being exploded out of the  cockpit  by  a  nitroglycerine
	charge, like a human cannonball.  The ejection itself was
	so  hazardous -- men lost knees, arms, and their lives on
	the rim of the cockpit or had the  skin  torn  off  their
	faces  when  they hit the ``wall'' of air outside -- that
	many pilots chose to wrestle their aircraft to the ground
	rather than try it .  .  .  and died that way instead.


	So if an astronaut chose to eject a few seconds before the
explosion (if there was enough warning to warrant the ejection), the
followin chain of events would occur with a high rate of probability:

	First the ejection seat would intercept the wind shear layer.
		Loose articles of clothing overstressed(ripped) by the
		supersonic wind. Super cooling would occur since astronauts
		do not wear insulated flight suits. Explosive decompression
		occurs due to traumatic shift of felt altitude (sea level to
		54000 feet.

	Second the seat would intercept the orbiters exhaust path and become
		super heated by the hot gasses.

	Thirdly the astronaut would asphyxiate while seat drops to 15000 feet
		before chute opens.

	Fourthly the shute would fail since it was crisped by the exhaust
		gasses and seat would plummet to the ground.

Conclusion: Ejection seats are just added weight since they would not improve
	    the chances of survival. I do not reccomend their placement in
	    the shuttle.

Peter Barada
...!ihnp4!ima!pbear!peterb