A one-and-one-eighth-inch socket from a torque wrench fell from a service platform and hit the shuttle Atlantis' left payload bay door radiator during Hubble Space Telescope cargo installation earlier this week. In a lucky break for NASA's shuttle team, no one was injured, coolant lines in the radiator were not damaged, and a dent where the socket impacted will not need repairs.
Atlantis is tentatively scheduled for liftoff May 12 on a fifth and final mission to service, repair, and upgrade the Hubble Space Telescope. Shuttle managers planned to meet Friday for a second round of discussions on whether to move the launch up one day.
NASA relies on tracking and telemetry equipment operated by the Air Force Eastern Range, and a previously scheduled military operation will prevent any shuttle launches for about a week, starting May 14. By moving launch up one day, to 2:01:49 p.m. on May 11, NASA could make three attempts in a row before standing down for the military operation.
The payload for the long-awaited mission--two new science instruments, new batteries, stabilizing gyroscopes, and other critical equipment--was delivered to launch complex 39A on Saturday and mounted in a payload changeout room in the pad's rotating service structure. After the RSS was moved into position around the orbiter's fuselage, the payload was installed in the shuttle's 60-foot-long cargo bay Wednesday.
The torque wrench socket fell from an upper-level access platform in the payload change-out room and hit Atlantis' left payload bay door aft radiator panel about 2 inches from the inboard edge and 5.5 inches above the panel's bottom edge. Two workers experienced glancing blows, one on the arm and one on the back. A NASA spokeswoman said medical exams showed no injuries.
Embedded Freon coolant loops in the radiators carry away heat generated by the shuttle's electronics, but an inspection revealed that the socket hit the face sheet over aluminum honeycomb material between two Freon lines and did not damage the cooling system.
Ultrasound inspections showed possible debonding between the face sheet and the underlying honeycomb, where the socket impacted. But additional inspections showed that the dented face sheet was not cracked, and managers decided that no repairs were necessary.