Shuttle Atlantis Short-Circuit Probe Continues

NASA is continuing an analysis of a short-circuit that knocked out an electronics box during the May 11 launch of shuttle Atlantis, but the problem isn't expected to delay in the upcoming launch of Endeavour.

Endeavour and seven astronauts remain scheduled for launch at 7:17 a.m. June 13 on a mission to deliver the third and final section of the Japanese Kibo science research facility to the International Space Station.

NASA engineers and managers, however, are continuing to analyze a short circuit that crashed an avionics box that amplifies signals sent to the shuttle's flight control system during atmospheric reentry and landing.

Engineers today briefed shuttle program managers on their latest analyses. Telemetry beamed back to Earth during Atlantis' nine-minute climb into orbit show the short circuit likely came from wiring associated with the avionics box as opposed to the box itself.

An examination of the box and associated wiring in the shuttle's aft engine compartment will be a high priority after Atlantis is ferried back to Kennedy Space Center from a back-up landing site at Edwards Air Force Base. Technicians will not be able to access the area until the shuttle returns to its homeport.

Engineers and managers think the problem is specific to Atlantis and that it is highly unlikely that Endeavour would suffer the same failure. A failure would cause a loss of redundancy in flight but in and of itself would not be critical.

Atlantis is scheduled to depart Edwards at first light Sunday and make a two-day trip back to KSC. A protective, aerodynamic tailcone still must be mounted around the shuttle's three-main engines and it is possible that high winds could delay that work.

NASA officials say the earliest Atlantis might arrive back at KSC is Monday afternoon. Even in that case, it's unlikely that the failed electronics box can be removed and tested -- and associated wiring inspected -- prior to an executive flight readiness review next Wednesday.

NASA managers, however, still could set a firm June 13 launch date and press ahead, with launch approval pending on the final analyses of the tests and inspections. The subject in that case would be reviewed at a standard NASA management meeting two days prior to launch.

ABOUT THE IMAGE: Click to enlarge and save the NASA photo of Atlantis in a gantry outfitted with a crane that will enable technicians to lift and mount the orbiter atop a modified 747 carrier aircraft prior to its ferry flight back to Kennedy Space Center.