THE first indication of trouble on shuttle Columbia was a
loss of temperature sensors in hydraulic system of left wing,
a NASA official said today.
The crew of Columbia pointed out technical difficulties in
the seconds before the space shuttle disintegrated over Texas
as it re-entered the Earth's atmosphere.
Ron Dittemore, the shuttle program manager, said that
during Columbia's liftoff, a piece of insulating foam from the
fuel tank was believed to have hit the left wing.
Dittemore said the loss of the sensors on the left wing was
followed seconds later by several other problems, including a
loss of tyre pressure and indications of excessive structural
heating.
"Our thoughts and our prayers go out to the families of
Rick and Willie and Davie and Kalpana, Michael and Larel and
Ilan. True heroes," he said.
It was possible that debris that struck the left wing of
Columbia during takeoff may have played a role in the space
shuttle's breakup, Dittemore said.
"And so as we look at that now in hindsight, that impact
was on the left wing," he said.
"We can't discount that there might be a connection."
Dittemore said videos of the takeoff showed foam break free
of the craft and appear to strike the shuttle's wing.
"We spent a goodly amount of time reviewing that film and
then analysing what that potential impact of debris on the
wing might do and would there be any consequences... it was
judged that that event did not represent a safety concern," he
said.
"We can't discount that there might be a connection.
"But we have to caution you and ourselves that we can't
rush to judgment on it because there are a lot of things in
this business that look like the smoking gun but turn out not
even to be close."
Is it possible that missing heat shields near the wheel bay
could have caused heat build up in that area to a point
where the tyre could have caught fire?
View the sequence of the events below:
08:53
20 to 30 degree rise in temperature in left wheel
well over 5 minutes.
08:54 (Eastern California & Western Nevada)
Mid-fuselage bond line (bond between fuselage and
top of wing on the port side) has a 60+ degree temperature
rise over 5 minutes. Starboard side is nominal at
15+. Inside of the Orbiter's fuselage wall, the temperature
is nominal.
8:56 a.m.
Sensors detect rise in temperature and pressure in
tires on the shuttle's left-side landing gear.
8:58 a.m.
Data is lost from three temperature sensors embedded
in the shuttle's left wing.
I would guess that the rubber tyre had caught fire,
soon followed by the hydraulic fluid.
Flight Control problems noted may have been caused
by the left main-gear door then opening.
Cause: No clue in last contact
