Spaceflight

Despite talk of damage, telemetry from the Space Shuttle during ascent and on orbit was "in-family nominal", says Columbia accident investigation board member Scott Hubbard. "As far as we can tell from the telemetry, it looked like the mission was fine," he says.

NASA has recovered the first 5s and last 2s of the 32s of corrupted data that followed loss of communications with Columbia. The first 5s show the orbiter was running normally, except for the temperature rises and sensor failures. The yaw control thrusters were firing, attitude was stabilised and the vehicle was under control. The auxiliary power units (APUs) were running.

The last 2s show the APUs, electrical generators, flight computers and navigation systems were still running, but hydraulic fluids were at zero and hydraulic fluid reservoir levels at 0% for all three systems. "The conclusion seems to be...that somewhere in the 25s of unrecovered data there was some sort of a failure that affected all three hydraulic units," says Hubbard. There were no signals from the left wing in the final 2s, says Gehman, who describes the empty hydraulic reservoirs as a "big anomaly".