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US space shuttle Endeavour landed safely back on Earth
Tuesday after a two-week mission to the orbiting
International Space Station. The crew included astronaut
Barbara Morgan, the first teacher in
space. Morgan's mission came 21 years after Christie
McAuliffe, the first 'educator astronaut,' perished in the
1986 explosion of the shuttle Challenger.
The shuttle landed at Kennedy Space Center at 12:32 p.m.
Eastern time. Within 30 minutes, six of the seven astronauts
climbed out and inspected the ship, but Barbara Morgan --
who was wobbly after her stay in the weightlessness of space
-- remained inside NASA's astronaut transporter. She had
been the designated backup to teacher-astronaut Christa
McAuliffe for the 1986 Challenger flight, which exploded
during launch, killing all seven crew members.
Douglas Hagerman suggested that this would be a particularly
numinous event because of the history. In addition, the event
was of higher than usual profile because the
shuttle suffered some damage
shortly after taking off on August 8 when a piece of foam
that broke off the external fuel tank, possibly accompanied
by some ice, hit the belly near the landing gear hatch 58
seconds after liftoff, leaving a small gash.
We set the formal event to include 1 hour prior to the
landing and 3 hours after, namely 1532 to 1932 GMT.
The data during the four hour period have a positive trend
with a Chisquare of 14716.730 on 14400 df for p = 0.032 and Z =
1.857.
For context, we look at the full 24 hour GMT day in the next
figure. There are lengthy periods that appear to show some
structure, including a strong negative slope early in the
day, but a few hours before the landing, the trace takes on a
positive trend that persists through the rest of the day.
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