NASA's own engineers refused to pronounce it the way the public did, and history has largely squeezed it between Mercury's firsts and Apollo's glory. But Project Gemini, which ran from 1961 to 1966, was the crucible where the United States learned to rendezvous, dock, spacewalk and survive two weeks in a capsule the size of a car's front seat. This deep dive draws on NASA records and flight logs to give the program its due.

The episode covers Jim Chamberlin's fighter-jet design philosophy, the 59-pound onboard computer, the Gusmobile interior tailored to a 5-foot-6 astronaut that 14 of 16 pilots could not fit into, and the controversial decision to replace the escape tower with ejection seats atop a hypergolic Titan II. It then walks through the counterintuitive physics of orbital rendezvous, the Gemini 8 emergency with Neil Armstrong, the  ...