Weather Also Poses Potential Conflict
The countdown to the scheduled Tuesday morning launch of space
shuttle Discovery on the STS-120 mission is proceeding on schedule,
NASA Test Director Steve Payne told reporters Monday. But that
doesn't mean all's clear for the shuttle flight.
"At this point in the count, we're on schedule, our systems are
all good and we're in great shape," Payne said, adding that the
launch team is not tracking any technical issues. However, the
weather forecast for Tuesday continues to pose a threat to NASA's
launch plans.
Shuttle Weather Officer Kathy Winters reported the seabreeze
could begin developing by the 1138 EDT launch time. There is a
60-percent chance that cumulus clouds, showers and a low cloud
ceiling could keep Discovery grounded for Tuesday; earlier
scheduled launch times for Wednesday and Thursday improve the
orbiter's odds of liftoff.
Despite receiving the all-clear to launch last week by NASA
mission officials, there are those at the agency who would have
preferred to see Discovery stay on the pad, the Palm Beach Post
reports, until three worn heat tiles are repaired or replaced.
As ANN reported, three of the
44 reinforced carbon carbon (RCC) tiles that line the edges of
Discovery's wings show signs of degradation in their outer coating.
Roughly half of the engineers on NASA's shuttle safety team
recommended the agency pull Discovery back to the Vehicle Assembly
Building, to replace the tiles... adding several weeks to an
already tight launch schedule.
Damage to the RCC tiles, caused by a falling chunk of insulating
foam from the orbiter's external fuel tank, brought down Columbia
in 2003.
After studying the problem, program manager Wayne Hale said last
week the agency ruled the issue posed "an acceptable risk," saying
the issue has cropped up on past shuttle flights, without leading
to catastrophic failure of the shuttle's heat shield.
"There was a great deal of evidence presented, and the
preponderance of evidence in my mind says that we have an
acceptable risk to go fly," Hale said in an October 16 mission
briefing. "And let me make sure you understand that. I didn't say
it's safe to go fly and I wouldn't say that. We have an acceptable
risk to go fly."
NASA is under the gun to complete the International Space
Station, before the shuttle fleet is retired in 2010.