Before NASA's Atlas 9 mission, the longest amount of time an American had spent in space had been a whopping 9 hours and 13 minutes -- a record set by Wally Schirra, who made six orbits of Earth for the Mercury program in October of 1962.

And then Cooper, the seventh member of the "Original Seven," came along. Gordo, for his part, spent a total of one day, 10 hours, 19 minutes, and 49 seconds in space, making 22 full orbits of the planet before splashing down in the Pacific on May 16, 1963. (His flight overall took 34 hours.) Over the course of his long voyage, Cooper had a dinner of "powdered roast beef mush" washed down with water. He captured mesmerizing pictures of the Earth below. He became the first American to sleep in space.

The story doesn't end there, though: Cooper also ran into some trouble. On his 19th orbit, the solo astronaut encountered a problem with the indicator light on the craft he named himself, Faith 7. On the 20th, he lost his attitude readings. On the 21st, a short-circuit occurred, leaving the tiny craft's automatic stabilization and control systems without electrical power.

Suddenly, the crackling radio connecting Gordo to Earth became even more crucial than it had been before. John Glenn, aboard a ship in Japan at the time, communicated with Cooper as he swept around the planet, helping the solo space traveler to revise the checklist NASA had prepared for his entry back to Earth. Meanwhile, Mercury Control Center was in a flurry of worried activity," one history has it, "cross-checking Faith 7's problems and Cooper's diagnostic actions with identical equipment at the Cape [Canaveral] and in St. Louis, then relaying to each communications site questions to ask and instructions to give."

The team soon had another problem to wrestle with: rising carbon dioxide levels in Cooper's craft -- and in his suit. The cabin temperature was rising to 100 degrees Fahrenheit. "Things are beginning to stack up a little," Cooper told the ground of the issue, understatedly.

Indeed. Throughout all this, reports make a point of emphasizing, Cooper -- alone in space, in a tiny, malfunctioning pod named Faith -- remained calm. This was in part because he had taken a medically prescribed pill of dextroamphetamine, stimulating his alertness. But it was also because these are the kinds of situations that astronauts, then as now, are trained for. Ground Control determined that Cooper, given the problems Faith 7 was experiencing, would need to make a manual re-entry back to Earth. The margin of error for angling the craft correctly would be slight: If Cooper came in too steeply, g-forces would crush him; if his trajectory were too shallow, the craft would bounce off the atmosphere and be shot back into space.