Gemini 9A returned to Earth after three days testing rendezvous techniques crucial for the coming Apollo missions. The mission's docking target had failed to reach orbit properly during a launch mishap, and a replacement Augmented Target Docking Adapter suffered a shroud malfunction that Command Pilot Tom Stafford famously described as an 'angry alligator,' preventing docking. Gene Cernan also conducted a grueling, near-disastrous spacewalk before splashdown.
Gemini 9A was NASA's second attempt at this mission slot after the original Agena target vehicle crashed into the Atlantic Ocean during its own launch in May 1966. A backup docking target, the Augmented Target Docking Adapter, was rushed into use, but during its own launch, the protective shroud covering its docking mechanism failed to separate fully, leaving it dangling and useless.
Tom Stafford, flying the mission with rookie Gene Cernan, maneuvered close enough to inspect the tangled wreckage and radioed the unforgettable description that it looked 'like an angry alligator' with jaws open. Docking was impossible, but the crew still practiced multiple rendezvous techniques, valuable rehearsal for lunar missions to come.
Cernan's spacewalk turned into one of the era's most harrowing spaceflight ordeals. Without adequate handholds or foot restraints, he fought exhaustion, his heart rate spiking dangerously and his visor fogging so badly he could barely see, as he attempted to test a rocket backpack. He nearly didn't make it back inside the capsule. The mission concluded on June 6 with a successful splashdown in the Atlantic, having proven, painfully, how much engineering work remained before spacewalks and dockings could be routine.