National Geographic : 1955 Nov
Twentieth Anniversary of the Epoch-making Stratosphere Flight by Explorer II 707 THE date: Armistice Day, November 11, 1935. Grouped around radios, millions of Americans listened to the laconic conversation of two men suspended in a metal ball more than 13 miles above the earth. Capt. Albert W. Stevens and Capt. Orvil A. Anderson had ridden the Explorer II strato sphere balloon to a new world's record alti tude of 72,395 feet. Their flight, sponsored by the National Geographic Society and the U. S. Army Air Corps, was launched from a cliff-encircled depression-the Stratobowl in South Dakota's Black Hills near Rapid City. After 8 hours and 13 minutes aloft, the flyers brought their instrument-laden gondola safely to rest near White Lake, South Dakota, 230 miles from the launching site.* Flight's Value Grew with the Years November, 1955, marks the 20th anniver sary of that epoch-making flight. The data it yielded opened broad new avenues of in vestigation. Yet in 1935 not even Explorer II's sponsors could gauge the richness of their legacy to the aeronautical sciences. That fact was often stressed by General of the Air Force H. H. Arnold, a trustee of The Society until his death in 1950. He stated that the stratosphere expedition "bore fruit in World War II far in advance of what was imagined to be the results at the time." The Army Air Forces' wartime commander referred in particular to lessons learned from the use of strong magnesium alloy for the hull of the nine-foot spherical gondola, the success of the gondola's advanced pressurized cabin, its two-way radio communication with the distant earth, and items of personal equip ment, such as electrically heated flying suits. "Many other items of equipment and meth ods were improved which later played im portant parts in giving American airmen su periority in the skies of Berlin and Tokyo," the General added. Explorer II carried 64 scientific instruments aloft. They provided much of the informa tion on which scientists based stratosphere research in the intervening years. Dr. Hugh L. Dryden, director of the Na tional Advisory Committee for Aeronautics and a life trustee of The Society, summarizes the expedition's sky soundings as follows: "About a ton of scientific apparatus pro duced new data on the direction of travel, number, and energy of cosmic rays; the dis tribution of ozone in the upper atmosphere; the spectra and brightness of sun and sky; the chemical composition, electrical conduc tivity, and living spore content of the air above 70,000 feet, and radio transmission from very high altitude." Dr. Dryden also cites the unique color photographs made of earth and sky. But per haps the most significant accomplishment, he points out, was the "convincing demonstra tion that man could protect himself from the environment of the stratosphere, from air so thin that the fan for rotating the balloon was ineffective, and from severe cold of 80° Fahrenheit below zero." The U. S. Air Force's Bell X-1A now holds the unofficial record for man's farthest aloft 90,000 feet, or approximately 17 miles. But the rocket-powered plane stayed that high only a few seconds. Stevens and Anderson were above 70,000 feet for one hour and 40 minutes, an achievement yet unequaled. A New Explorer Challenges the Old Explorer II still holds the altitude record for a manned balloon. But she may lose that distinction soon to a namesake, Explorer III of the U. S. Air Force. Two young para chutists, Capt. Edward G. Sperry and 1st Lt. Henry P. Nielsen, plan to take this balloon 90,000 feet or higher and jump. Their pur pose: research in survival problems of flyers forced to eject from tomorrow's planes.t Captain Stevens, commander of the Ex plorer II, held the retired Army rank of lieutenant colonel at his death in 1949. Cap tain Anderson, the pilot, became a major general in the Air Force, retiring in 1950. Today, in retrospect across two decades, aviation recognizes their flight as vital to research that followed, research that now promises unmanned earth satellites and, even tually, voyages by man into space. * For full accounts of the Explorer II flight, see, in the NATIONAL GEOGRAPHIC MAGAZINE: "Man's Far thest Aloft," January, 1936, and "Scientific Results of the World-Record Stratosphere Flight," May, 1936, both by Capt. Albert W. Stevens. See also "National Geographic Society-U . S. Army Air Corps Strato sphere Flight of 1935 in Balloon Explorer II" (Con tributed Technical Papers, Stratosphere Series, No. 2), published in 1936 by National Geographic Society, Washington, D. C. t See "Aviation Medicine on the Threshold of Space," by Allan C. Fisher, Jr., NATIONAL GEO GRAPHIC MAGAZINE, August, 1955.