Pad repairs won't delay Hubble mission

Kennedy Space Center, Florida - NASA settled on a go-forward plan today for repairs to the damaged flame trench at Kennedy Space Center's launch pad 39A, and officials say the work will not trigger a delay in the planned Oct. 8 launch of Atlantis and seven astronauts on NASA's fifth and final Hubble Space Telescope servicing mission.

Starting Friday, technicians will work two 10-hour shifts a day to clear debris and damaged brick from the east wall of the pad's north flame trench, which sustained significant damage during the May 31 launch of Discovery on a mission to delivery the Japanese Kibo science laboratory module to the International Space Station. The clean-up effort is expected to take about 14 days.

Then NASA will patch two areas with steel grid and a refractory concrete called "fondue fire" that is applied in much the same way contractors spray gunite to build back-yard swimming pools. The area to be repaired on the east wall is 25 feet high and 100 feet wide. On the west wall a 25-foot-high area that is 80 feet wide also will be patched up. Total cost: $2.7 million. The job should be done by the third week in August, clearing the way for Atlantis to be rolled out to the pad as scheduled on Aug. 29.

An estimated 3,540 flame-retardant bricks were torn away when Discovery's blasted off, sending up a billowing cloud of smoke and steam that reached temperatures near 3,600 degrees Fahrenheit while accelerating debris at supersonic speeds. Built with concrete and refractory bricks, the 490-foot-long trench -- which is 42 feet deep and 58 feet wide -- deflects flame from the shuttle's two towering solid rocket boosters and three liquid-fueled main engines. Discovery was not damaged, and transport analyses show it would be highly unlikely that a shuttle ever would be struck by flame trench debris.

Investigators say the damage was done when flame sneaked behind previous patch-work -- an intrusion that weakened an unseen fracture and ultimately blew out the bricks. The repair work is expected to hold up through the end of the shuttle program in 2010.

NASA officials also examined the flame trench at pad 39B, where the agency aims to launch the first Ares 1 test flight by the middle of next year. Some repair work might have to be done before that flight; more major work probably will be required before Ares 1 rockets and Orion spacecraft begin operational flights in the middle of the next decade.