Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU
Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!space
From: dsmith@HPLABSC (David Smith)
Newsgroups: net.space
Subject: Re:  Future of the Space Program
Message-ID: <8601292328.AA16795@hplabsc>
Date: Wed, 29-Jan-86 18:28:40 EST
Article-I.D.: hplabsc.8601292328.AA16795
Posted: Wed Jan 29 18:28:40 1986
Date-Received: Sat, 1-Feb-86 02:51:41 EST
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 49

> - What kind of escape mechanism (if any) does the shuttle have for the crew?

None.  Columbia had ejection seats for the first test flights, but this
happened too fast for ejection seats.  Explosions like this were the reason
for the escape towers on Mercury and Apollo.  The escape tower saved two
Soviet cosmonauts from a launcher explosion in 1983, although they had
extended hospital stays.

> - Might this redirect (to some extent) the focus of the manned space
>   program away from the shuttle (large, complex) back toward simpler or
>   alternative launch systems?

It astounded me that the orbiter and ET were completely obliterated, while
the SRBs flew out of the fireball apparently intact.  This suggests that
ths SRB-X proposal might produce a good, reliable launcher (for unmanned
payloads).  SRB-X consists of two SRBs side by side for a first stage, with
one SRB on top as the second stage.  While solid propellant is more
expensive than LH/LOX, a savings would come from not launching the weight
of the manned compartment when the mission does not otherwise need to be
manned.  Manned launches could be via transatmospheric vehicle, which would
be much smaller than the current Shuttle, not carrying the heavy cargo and
(explosive) propellant for the cargo.  Being air breathing through the
atmospheric boost phase, it wouldn't have so much LOX to tangle with its LH.
Manned missions requiring heavy equipment would use orbital rendezvous.  

About the press: I am still surprised at how imperceptive the newscasters
were.  They played the tapes over and over in slow motion, pointing out
that the fire started between the orbiter and ET at about the forward
attachment point.  Finally they discovered the earlier fire at the rear of
the tank.  These were said to be two separate fires.  By Tuesday night,
Rather was saying that the fires may have been breaches of the left (nearer)
SRB, in spite of the fact that the SRBs didn't have any flame out their
sides after emerging from the fireball.  The V-2 was solid fueled.  Etc., etc.

Here's what I think.  There was a leak in the hydrogen tank or its
connections, as evidenced by the cloud that gathered around the base of the
tank unnoticed by newscasters.  The short-lived flame plumes near the 
closer SRB were ignited in the cloud of hydrogen by the rocket exhaust.
Perhaps they went out for lack of atmospheric oxygen:  the SSME exhaust is
hydrogen rich.  But before long, the cloud really caught;  the fire spread
around the back side of the tank (as seen from the camera) to appear
between the tank and the orbiter.  By this time, more hydrogen was coming
out of the tank.  The fire climbed the oxygen line to the oxygen tank.
The explosion which ripped the vehicle apart was centered at the join
between the O2 and H2 tanks.

			David Smith
			hplabs!dsmith
			dsmith%hp-labs@csnet-relay