Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Shuttle Astronauts ... ALIVE ?!?!??
Message-ID: <1988Sep17.073035.29265@utzoo.uucp>
Organization: U of Toronto Zoology
References: <14956@ames.arc.nasa.gov>
Date: Sat, 17 Sep 88 07:30:35 GMT

In article <14956@ames.arc.nasa.gov> chguest@nike.UUCP (Charles Guest  RCE) writes:
>A few weeks back I heard of or read somewhere that the challenger
>astronauts (or some of them anyway), may have survived the initial
>explosion long enough to accuate some sort of emergency oxygen or
>life support system...

Sigh.  Eugene, better put this one in your frequently-asked-questions
compilation.

The most relevant document here is the medical and forensic report from
the team headed by (astronaut and MD) Joe Kerwin.  The stresses involved
in the disintegration of the orbiter and external tank were well within
normal human limits, and are quite unlikely to have caused either death
or major injury of the astronauts.  (The external tank did not explode,
it came to pieces and the propellants burned rapidly.  The orbiter,
somewhat damaged, was thrown out of control and was torn apart by the
hypersonic slipstream.)  The crew cabin survived as a single unit and
hit the ocean slightly battered but basically intact.  Several of the
emergency air packs, intended to provide breathing during an emergency
escape on the pad, had been activated.  It appears vanishingly unlikely
that this could have been caused by anything but human action.  It is
impossible to avoid concluding that most or all of the crew survived
the orbiter breakup, and at least some of them were conscious for at
least a few seconds afterward.  Almost certainly they were killed by
impact with the ocean, not by the accident itself.  (There were no voice
or other recorders running for more than a fraction of a second after
breakup, the cabin was badly smashed by the water impact, and the bodies
were under water for weeks before recovery, so it is hard to be positive 
of most of this.)

One remaining uncertainty is whether the crew were conscious all the way
down.  The key question is whether the cabin held pressure.  The emergency
packs held *air*, not *oxygen*, and would not have prevented quick loss
of consciousness at the breakup altitude.  Consciousness probably would
not have been regained before impact, once lost.  Kerwin's team worked
very hard to try to determine whether the cabin had held pressure, but
ultimately could not be sure -- the impact damage was just too great.
In particular, it was not possible to determine with certainty whether
any of the windows had broken during the breakup.  If one had to guess,
the best guess [in my opinion -- Kerwin's team did not guess] is that the
cabin lost pressure quickly and the astronauts rapidly lost consciousness,
but certainty is not possible.
-- 
NASA is into artificial        |     Henry Spencer at U of Toronto Zoology
stupidity.  - Jerry Pournelle  | uunet!attcan!utzoo!henry henry@zoo.toronto.edu