American balloonist who, in November 1935, ascended to a then-record altitude of 72,395 feet (19,150 m) in the balloon, Explorer II. During a previous ascent in July, 1935, Stevens's balloon ruptured at an altitude of 60,000 feet (15,870 m), nearly taking Stevens and his crew to their deaths before they bailed out at less than 6,000 feet (1,590 m). During their November ascent, however, no such problems occurred, and the crew was able to make a number of important scientific observations.