Cernan wore a stiff, pressurized spacesuit as protection from the vacuum and heat and cold of space. He struggled mightily for several hours against the inflexibility of his suit and his gloves, all the while trying to control his movements in the weightless environment while connected to the spacecraft with a long, uncooperative tether. His heart rate tripled … his helmet fogged tremendously … and ultimately, his attempt to strap on a small rocket pack was aborted. But his biggest challenge lay ahead.
As Cernan wrote in his 1999 book The Last Man on the Moon: Astronaut Eugene Cernan and America's Race in Space, squeezing back into the small spacecraft was almost impossible, especially after the unexpected exertion of the spacewalk. “My goal was to get my butt flat in the seat and my spine against the backrest, but that was impossible because of the stiff, inflated suit. Effort turned to struggle, then to outright fight as I gained territory a sweaty millimeter at a time. My heart rate, which had calmed somewhat, shot up again as I squirmed about, and I was sucking air forty times a minute,” he writes. “It was worse than trying to stuff a cork back into a champagne bottle.”
“Eventually, I was halfway in and halfway out the spacecraft, still using all my strength to shove my bulk down into the cabin. I forced my shoulders below the level of the hatch, scrunched down as hard as I could, bent my neck and at an impossible angle, and pulled the hatch. It hit the top of my helmet and wouldn’t close. Sonofabitch! I was still not in far enough.”
His crewmate, Tom Stafford, was able to reach over from his seat and pull down on the hatch, managing to pull it another couple of inches down and engaging the first tooth of a closing ratchet. “Another scrunch, and I was in awful pain,” writes Cernan. “… I was frozen in place by the suit, unable to unfold my feet, which were still tight beneath me. … More work, more clicks from the closing ratchet as I ground my teeth. … I’d never known such pain. … I gave the handle a last twist, and the hatch finally locked tight.”
“I might admit that I was crying, but only Tom really knows,” Cernan writes.