Gemini 9 to Gemini 12: Learning to Work in Space

On Gemini 9, Cernan estimated that maintaining position consumed 50 percent of his workload.

On Gemini 9, exertion overwhelmed moisture removal, fogging Cernan’s visor and temporarily blinding him.

On Gemini 12, body restraints, procedures, and underwater training made attempted EVA tasks feasible.

On Gemini 12, monitoring Aldrin’s physical condition allowed him to be told to rest before fatigue developed.