The backup crew and some support crew participated in an interesting rescue scenario with 2 astronauts flying to Skylab to take back the crew of 3 onboard Skylab. This would mean 5 astronauts returning to earth in the command module.
Neutral Buoyancy Simulator at MSFC
Gibson Training at ATM Simulator
3rd Crew at Mission Training and Simulation Facility at JSC
Aside from physically training for the longest crewed missions that the United States had ever attempted, the actual training program was developed simultaneously with the hardware and experiments for the mission.
Ten days ago, their Saturn V rocket had blasted Bean and his crew mates out of earth’s gravitational pull. Now their home planet was pulling them back at more than 24,000 miles per hour, twelve times faster than a high-speed rifle bullet. “Boy,” said Bean, “we are really hauling!”
Dick Gordon opened the tunnel to Intrepid, saw his companions floating in a dirty cloud of moon dust, and slammed the hatch closed. He called out, “You guys ain’t gonna mess up my nice clean spacecraft!”