The Mercurial Challenges and Lunar Comfort in Apollo Flights

When compared to the cramped and confining crew space in the Mercury and Gemini spacecraft, astronauts found Apollo positively luxurious. Mercury's habitable pressurized volume was a mere 100 cubic feet, divided in half by the pilot's seat and instrument panel, leaving just enough room for a single man to sit strapped in his seat. On the final two Mercury missions, astronauts Wally Schirra and Scott Cooper unbuckled their straps, but the tiny confines limited their movements. Gemini's pressure vessel contained a meager 90 cubic feet, roughly the volume of a Volkswagen front seat. The crews remained in their ejection seats for up to 14 days, where the cramped nature of the craft did not allow for much movement. On Gemini missions 5, 9, 10, 11, and 12, one of the crew would step outside the ship to perform an EVA, only then stretching their limbs. The Apollo Command Module (CM) offered a far more spacious 218 cubic feet of habitable pressurized volume for three men, allowing them to fold up and stow their couches, providing ample room to stand and move about simultaneously. On flights 9 through 17, the CM was docked to the Lunar Module (LM), adding an additional 235 cubic feet of habitable space. This design change meant that at least on the outward leg of those missions, some of the crew could spend part of their time in the LM.

The Zero G Environment and Freedom from Straps

It is important to remember that in Zero G, every surface becomes a wall. During a mission, astronauts did not have to stay strapped into their seats throughout. This flexibility was a significant improvement over the earlier spacecraft.

The Gemini Program and Space Endurance Testing

The Gemini program played a crucial role in testing space flight endurance. For instance, Gemini 7 was a 14-day mission in Earth orbit, significantly more cramped and claustrophobic than the Apollo spacecraft. Gemini missions were designed to serve as dress rehearsals for astronauts, pushing the limits of endurance and providing valuable feedback on aspects such as food, sleep schedules, suiting up procedures, and "bathroom breaks." Imagine sitting in your car for 14 days; this is what the astronauts faced, with the knowledge that their friends would do the same in a month's time, using their experiences to inform and improve conditions for extended space missions.