New Foam Application Method Could Return Shuttle To Flight
By Mid-2006
By completely removing a foam ramp from the exterior of the
space shuttle's external fuel tank, NASA hopes to eliminate the
foam insulation breakage problem that caused tense moments during
Discovery's return-to-flight in July.
The 37-foot long ramp -- a long foam protuberance running down
the tank, designed to smooth airflow over the tank at high Mach
speeds and ease vibration to nearby piping and cables -- was the
source of the one-pound chunk of foam insulation that broke off
during Discovery's launch, nearly hitting the orbiter's right
wing.
According to media reports, the ramp would be replaced by
more-exacting foam placement, as well as sensors to measure the
resulting aerodynamic forces. A similar technique was used on the
Discovery flight, when a 10-foot section of the same ramp was
removed for a safety modification prior to the launch.
The foam that was then applied to the affected section stayed in
place during the launch, giving engineers hope that the complete
removal of the ramp will solve the problem.
According to Johnson
Space Center spokesman Kyle Herring, NASA shuttle chief Wayne Hale
met with managers Thursday and asked if a second test flight could
be launched in May, with an ISS assembly flight following in July
-- a brisk timetable by recent NASA standards.
Herring said Hale told the managers "these are not launch dates,
but I just want you guys to come back and tell me what it would
take to get there -- if we can get there."
Foam insulation issues, as well as damage wrought to NASA
facilities by the recent hurricanes, have all but ruled out NASA's
original March return-to-flight date. "I think that May would be
the earliest, based on two hurricanes that not only caused damage
at some of the facilities but also displaced the work force,"
Herring said.
Shuttle fuel tanks are assembled at NASA's Michoud Assembly
Facility in New Orleans, which was heavily damaged by Hurricanes
Katrina and, to a far lesser extent, Rita. Many of the 3,500
workers who work at Michoud, as well as Stennis Space Center in Bay
St. Louis, MS, are still living in temporary housing, and NASA
estimates it will take approximately $1.1 billion to repair the
damage to both facilities.
Nevertheless, workers at Michoud are back on task, and they will
play a crucial role in implementing the proposed fix to the fuel
tank currently slated to fly on the next shuttle mission.
"Even with the devastation to their lives, it's been kind of
remarkable that they have stepped up and are back at work and are
trying to balance that with their own personal issues," said
Herring.
Once the fixes are completed at Michoud, the tank will be
transported by barge back to Kennedy Space Center in Florida. The
tank would need to be returned to Kennedy in January in order to
launch Discovery in May.