Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site uiucdcs
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!inuxc!pur-ee!uiucdcs!irwin
From: irwin@uiucdcs.CS.UIUC.EDU
Newsgroups: net.columbia
Subject: Re: Challenger Destruct
Message-ID: <8500015@uiucdcs>
Date: Wed, 29-Jan-86 02:50:00 EST
Article-I.D.: uiucdcs.8500015
Posted: Wed Jan 29 02:50:00 1986
Date-Received: Sat, 1-Feb-86 00:00:20 EST
References: <540@ihlpl.UUCP>
Lines: 39
Nf-ID: #R:ihlpl.UUCP:540:uiucdcs:8500015:000:2272
Nf-From: uiucdcs.CS.UIUC.EDU!irwin    Jan 29 01:50:00 1986


Nope, no laser. The main fuel tank ruptured. I viewed several network
news broadcasts, saw the explosion in slow motion several times.

When the pilot advanced the throttle to 104%, the thing blew up. I
think, from the views of the flames licking the side of the main tank,
that volatile fuel was leaking from the main tank, somewhat toward the
nose of the tank. It was ignited by the exhaust flames as it passed
the tail of the rockets, the flash flame followed up the tank to the
hole, crack, whatever and she blew. It could well have cracked, where
the nose mount of the shuttle was attached to the tank.

The main tank, with 500,000 pounds of fuel to start, 1 and 1/4 min
into the flight had a lot of fuel left. If it was half, that would
be 250,000 pounds. At the G's they were pulling, that would multiply
to maybe a million pounds stress on the walls of the tank.

Remember, the solid fuel rockets are connected to the sides of the
liquid fuel tank, and the shuttle to the top of it. The fuel from
the tank supplies the engines in the shuttle, so the thrust from
the shuttle engines was lifting on the top of the tank. The thrust
of the shuttle engines did not bear all of the weight, as one has
to consider the lift factor of the solid rockets. This when summed
up, adds to one "H" of a lot of stress on the welded aluminum liquid
fuel tank. From what I saw, the liquid fuel tank cracked or ruptured
under the stress, and the leaking fuel was ignited by the thrust flames,
and she vaporized.

If one had the theory that one of the solid rockets flawed and burned
a hole in the liquid main tank, you would have seen a torch of flames
coming from the <side> of one or the other solid rockets. The views
of them as they continued to burn and move on, only showed flames from
the tail, where the flames should have been. Thus, the solid rockets
did not burn a hole in the liquid fuel tank to cause the leak. If you
sum this all up, it only leaves the rupture of the liquid fuel tank,
from stress. Note, this is my opinion, based on the vidio shots that
I saw. I may be proved wrong, but at this time, I think it makes sense.
They had already passed through the high vibration point, which could
have weakened the tank, and when they applied high throttle, it gave up.