NASA's top leaders decided
at a meeting Thursday to put off any further design changes to the space shuttle's external
fuel tank until after Discovery's flight in July, despite concerns raised by
engineers, including Bryan O'Connor, the space agency's chief safety officer.
The agency had been
considering changing the design of the tank's 34 so-called ice frost ramps to
stop insulating foam from falling off. Meeting participants were split, but top
leaders decided it was best to see how recent changes to the tank held up before making any more
modifications, space shuttle program manager Wayne Hale said last week.
Foam breaking off the
external tank at liftoff doomed
Columbia and its seven astronauts in 2003.
In an e-mail Monday,
O'Connor said he had recommended redesigning the ramps before the next flight,
but NASA Administrator Michael Griffin favored the opinion of the program
manager and an associate administrator to fly "as is,'' with plans to develop a
new design for future flights.
"I believe the discussion
of options and their risk trades were carried out professionally and with due
respect to all opinions,'' O'Connor said. "The agency accepts the risk of
flying the current configuration with its eyes open.''
Last week's meeting
illustrated that the space agency may have learned a major lesson from
management problems leading up to Columbia's disintegration upon re-entry, said
Adm. Harold Gehman Jr., former chairman of the now-disbanded Columbia
Accident Investigation Board.
"The old NASA would have
rolled over dissent,'' said Gehman, whose board concluded that dissent was
discouraged before the accident.
But James Hallock, a
Department of Transportation safety official, said he wished he knew more about
why O'Connor was overruled. If you're not going to listen to the safety
officer, "Why do you have one?'' he said.
Sheila Widnall, an
aeronautics professor at the Massachusetts Institute of Technology who also
served on the board, said she was still concerned that NASA hadn't solved the
tank's foam problem. The tank was redesigned for the first post-Columbia flight last
July, but foam still
came off.
"The thing I don't know ...
is why have the different approaches NASA has taken not been satisfactory?''
Widnall said.
Douglas Osheroff, a physics
professor at Stanford University who served on the board, said he worried that
NASA was facing political
pressure to fly in July.
"These guys are under an
awful lot of pressure,'' Osheroff said. "I surely would not want to be in
Griffin's shoes right now.''
advertisement
