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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: sci.space.shuttle
Subject: Re: Launching shuttles too soon (ALL NEW MATERIAL)
Message-ID: <7343@utzoo.UUCP>
Date: Mon, 24-Nov-86 15:27:50 EST
Article-I.D.: utzoo.7343
Posted: Mon Nov 24 15:27:50 1986
Date-Received: Mon, 24-Nov-86 15:27:50 EST
References: <7254@utzoo.UUCP> <346@xios.UUCP> <7275@utzoo.UUCP>, <2338@ihlpa.UUCP>
Organization: U of Toronto Zoology
Lines: 46

> 2.  On the policy issue, perhaps what NASA needs to do is equip only the
> replacement shuttle with an escape system.  Then, when hazardous conditions
> are discovered... there would still be one vehicle which could be flown...

Unfortunately, this assumes that escape systems suffice for safety.  As I
recall it (my copy of the report isn't handy), the Rogers Commission found
that no escape system would have helped.  They recommended investigating
an escape system for a different situation:  an intact orbiter flying at
low altitude, more or less under control, but with no airstrip handy.
(The orbiter is too flimsy to ditch or belly-land safely.  I've read the
STS-1 flight plan; all the sequences which involve descent into the ocean
end in "EJECT".)  Not even an escape capsule would suffice to get the crew
out of something like an asymmetric SRB ignition.

> 3.  On the escape issue, I wonder:  would Young and Crippen (?) have survived
> if the SRB failure had occurred on the first flight of Columbia?  Consider,
> somebody stayed conscious long enough to turn on two air packs, and the 
> official "cause of death" is now said to be impact with the Atlantic Ocean.
> This seems to imply that there is at least some chance that ejection seats
> could have been used before impact.  

Given that Young and Crippen were wearing spacesuits, and assuming that
damage to equipment or hatches didn't interfere, they could probably have
ejected if their suits had on-suit or on-seat emergency oxygen supplies
(I'm not sure whether they did or not).  The suits are important:  they
eliminate unconsciousness due to decompression (which almost certainly
knocked out the 51L crew within 10-20 seconds) and they provide enough
physical protection to make high-speed ejection practical.  Even modern
ejection seats are normally red-lined at around 600 knots, as I recall,
because the pilot isn't well enough protected against the slipstream.

> 5.  Back to the subject of resuming flights immediately: where would the
> payloads come from?  ...  Even spysats are doubtful--given the cost
> and lead time for replacing a Big Bird (or equivalent)...

The key point here is that the USAF is (a) well funded, and (b) in the
business of taking risks in the national interest.  Undoubtedly the USAF
would prefer not to take risks with its satellites, and indeed the USAF is
getting more openly anti-Shuttle by the day, but they can simply be given
orders otherwise.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,decvax,pyramid}!utzoo!henry