Explorer II Gondola
Launched on Nov. 11, 1935, near Rapid City, SD, Explorer II carried two aeronauts and an assortment of instruments to a world-record altitude of 22,066 meters (72,395 feet).
Explorer was the brainchild of Capt. Albert W. Stevens, chief of the Army Air Corps' photography laboratory at Wright Field, Ohio. With funding from the National Geographic Society, he attempted a world altitude-record flight in 1934 with Explorer I. The flight ended in disaster when the balloon ripped shortly after launch, and its hydrogen mixed with air and exploded. After a harrowing few moments while Stephens had trouble escaping through the manhole, he and his two fellow aeronauts parachuted to safety.
For his next attempt, in Explorer II, the manholes were widened for easier escape, and the balloon was filled with non-flammable helium. To ensure that it attained a record altitude, Explorer II's balloon was enlarged, the crew was cut from three to two, and its scientific payload (the stated rationale for the flight) was halved.
Like Explorer I, Explorer II was constructed of welded magnesium/aluminum alloy sections. The 2.8 meter (9-foot) sphere weighs 290 kilograms (640 pounds) and can carry a payload of 700 kilograms (1500 pounds).
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