Flight Readiness Review "Intensive and Spirited"
After two days of
"intensive and spirited" debate and deliberation, NASA's Flight
Readiness Review (FRR) Board gave the green light for a July 1
launch of Space Shuttle Discovery. "There were many different
viewpoints about whether we were ready to fly," said NASA
Administrator Mike Griffin, "and we've decided that we are." The
announcement came in a press conference Saturday.
Wayne Hale, Deputy Manager of the Space Shuttle Program, said
there were at least 250 people involved in the discussions.
"Contrary to prior FRRs, questions and concerns were accepted and
addressed from all people," said Hale. "Dissent was welcome."
In the end, NASA's safety engineer and chief engineer
recommended a "No Go" for launch until the foam surrounding the
tank's 37 ice/frost ramps could be redesigned. The engineers are
concerned that debris shed from the tank will damage the shuttle,
as it did in the launch that ultimately ended in Columbia's tragic
re-entry breakup in 2003.
True to what Griffin calls the agency's "new culture of openness
and healthy debate," the dissenting engineers were allowed to type
their concerns, in their own language, directly into the FRR Boards
final report.
In a surprisingly frank and open dialog with the press, Griffin
admitted the decision to fly was not unanimous. "You have to
understand that NASA gets a lot of external advice, and I get a lot
of advice internally. But, in the end, it's just advice. Somebody's
got to make the decision and that's what you pay me for."
"Debris shed from the tank does not represent an ascent risk,"
Griffin said, "it represents a descent risk." He would have had to
think harder about his "go" decision, he implied, if they did not
have a safe haven in the space station, a back-up space shuttle
ready to go for rescue, and, if necessary, assistance from
Russia.
Despite Griffin's confidence in the mission, Hale said that the
foam surrounding the ice/frost ramps is still at the top of NASA's
"risk chart."
"I have launched a ‘tiger team' to develop a new design in
rapid but thorough fashion," said Hale. "The risk is acceptable for
a limited number of flights until a new design is available."
Griffin was less comfortable even calling it a risk. "I do not
agree with categorizing [the risk of debris damage] as probable.
Now, in fact, we have had 114 flights with this vehicle. And, while
we've had two loss-of-vehicles incidents, they were not due to ice
frost ramps. Can we fly a number of flights without a probable
incident? I believe we can."
"This is a matter of programmatic risk," Griffin added, "not
crew risk. The shuttle will be retired in 2010. We need to accept
some programmatic risk and get on with it. That is not the same as
accepting crew risk." If the risk doesn't pay off, Griffin assured,
and NASA loses another shuttle vehicle, he will be the first to
call for an immediate end to the shuttle program.
William Gerstenmaier, NASA's associate administrator for space
operations, said the two-day FRR tackled lots of other issues
besides the foam and ice/frost ramps. "We reviewed everything we
could to make sure we were really ready to fly. Losses of ice/frost
ramp foam are expected to be similar to past launches, which are
acceptable losses for STS-121."
STS-121 and the next 15 consecutive missions are designed to
complete the construction of the international space station prior
to the scheduled phase out of the shuttle program in 2010.
Launch director Mike Leinbach said the processing of Discovery
was going extremely well and there were no problems that might
preclude a July 1 launch.
Preparations for Discovery's sister shuttle, Atlantis, were also
proceeding on schedule in the event it would be needed for a rescue
mission, according to NASA.
A rescue shuttle could be called up within 10 days of
Discovery's launch, and be in the air 47 days after that. Leinbach
said there would be a two-week window of launch opportunity at the
end of August and first week of September, and that Atlantis would
be ready for an August 21 launch if necessary. The Discovery crew
will have enough supplies on board for 82 days.
Countdown begins Wednesday, June 28 for a scheduled 3:43 pm EDT
launch from pad 39B at Kennedy Space Center.