Manhigh II balloon gondola displayed at the National Museum of the U.S. Air Force, Wright-Patterson AFB, OhioAs displayed in 2018
Project Manhigh was a pre-
Space Age military project that took men in
balloons to the middle layers of the
stratosphere, funded as an aero-medical research program, though seen by its designers as a stepping stone to space. It was conducted by the
United States Air Force between 1955 and 1958.[1]
Manhigh I to 29,500 m (96,800 ft), by
CaptainJoseph W. Kittinger on June 2, 1957. The balloon was launched from
South St. Paul Airport and the flight was cut short due to one of the capsule's valves being installed backwards which vented the oxygen supply outside, but not before reaching a record altitude of 96,784 feet.[1]
Manhigh II to 30,942 m (101,516 ft), by
MajorDavid G. Simons on August 19–20, 1957, launched from Portsmouth Mine in Crosby, Minnesota, for a 32-hour flight that included a set of 25 experiments and observations, and earned Simons a
Life magazine cover spot.[1][2] With the pilot and the scientific payload, the Manhigh II gondola had a total mass of 748 kg (1,649 lb). At maximum altitude, the balloon expanded to a diameter of 60 m (200 ft) with a volume of over 85,000 m3 (111,000 cu yd).
Candidates for the Manhigh project were put through a series of physical and psychological tests that became the standard for qualifying astronauts for the
Project Mercury, America's first manned orbital space program.[1]
Similar projects in which men in a gondola reached near-space altitudes were performed by Swiss physicist
Auguste Piccard and Paul Kipfer, reaching 15,785 m (51,788 ft) in 1931,
USSR-1 piloted by
Georgy Prokofiev reaching 18,500 m (60,700 ft) in 1933, and
Osoaviakhim-1 reaching 22,000 m (72,000 ft) in 1934 as well as
Explorer II reaching 22,066 m (72,395 ft) in 1935.