The Manual Backup That Brought Palapa B-2 Home

Transcript

In November 1984, the crew of space shuttle mission STS-51A set out to retrieve the communications satellite Palapa B-2. The satellite weighed 555 kilograms, and the spacewalk to recover it lasted six hours. The planned capture depended on a stinger, a probe that Allen inserted into the bell of the satellite’s apogee kick motor. He used the Manned Maneuvering Unit’s automatic attitude hold to stop the satellite from spinning. But Gardner could not attach the A-frame capture device, which was meant to secure the satellite. The crew turned to a rehearsed backup: Gardner held the satellite by hand while Fisher used the shuttle’s Remote Manipulator System, its robotic arm, to move him to the frame in the payload bay. The chronology records the manual hold and the move to the frame, without separately stating a later mission outcome. The episode shows why a practiced backup mattered: when the planned hardware connection failed, the crew had another procedure to continue the retrieval.