Astronaut Scott Carpenter wearing his Mercury spacesuit, 1962. Credit: NASA
Astronaut Scott Carpenter flew only one mission, a relatively short three orbit Mercury flight on May 24, 1962. Carpenter was Glenn's backup for the Friendship 7 mission and became the fourth American in space and second American to orbit Earth. He had been training closely with Glenn for months, and was the best prepared astronaut the agency had.
John Glenn had proved that an astronaut could be more than just a passenger in space, so with its second orbital mission NASA decided to really push the astronaut into a central role. Building on the experience gained from Glenn’s flight and seeking to gather as much scientific data as possible, Carpenter’s flight plan quickly filled up.
Scott Carpenter snaps views of Earth with a handheld camera, 1962. Credit: NASA
Carpenter would have more control over his spacecraft than Glenn. NASA wanted the astronaut to orient his spacecraft to see sunrises, day and night horizons, earthly landmarks, and find certain stars as navigation references. He was also covered in biomedical sensors which continually sent biomedical data back to mission control. His mission included various science, photography, and microgravity experiments.
During his first orbit, Carpenter inadvertently bumped his hand against the inside wall of the cabin resulting in a bright shower of particles outside the spacecraft - what John Glenn had called "fireflies" - which turned out to be ice particles shaken loose from the spacecraft's exterior. During his second orbit, Carpenter’s suit began to overheat and by the end of his five-hour flight, he had lost seven pounds, mostly through perspiration.
Scott Carpenter in the Mercury Control Center at Cape Canaveral, 1962. Credit: NASA
By the end of his second orbit, Carpenter's fuel supply had dropped to worryingly low levels – about 42 percent in the manual tanks and 45 percent in the automatic tanks. Houston told Carpenter that as long as he had 40 percent fuel in both tanks, he’d be ok. Any less, and the mission might end in disaster.
By the end of his third orbit, positioned over the islands of Hawaii, Carpenter began reentry. The Aurora 7 retro-fire rockets failed to fire automatically. The three seconds it took for Carpenter to fire them manually caused the Aurora 7 spacecraft to land in the Atlantic Ocean some 250 miles from its intended splashdown point. Two hours later he was winched aboard a recovery helicopter and flown to the USS Intrepid where he took congratulatory calls from Vice President Lyndon B. Johnson and President John F. Kennedy.