High-Altitude Balloons Take First Steps toward Space

Experiments with balloons in the 1940s and 1950s took human beings higher than ever, bringing with them space-observing scientific instruments.

A year before the launch of the Soviet Union’s Sputnik 1 satellite, manned flight reached closer to space using a more traditional method—a balloon. There was, however, nothing very traditional about this particular balloon.

Stratolab pilots in their pressure suits talk with Capt. Norman Lee Barr, the flight surgeon for the project.Stratolab pilots in their pressure suits talk with Capt. Norman Lee Barr, the flight surgeon for the project.
(National Geographic photo by Tomas J. Abercrombie)

Funded jointly by ONR and the National Science Foundation, this balloon was made out of polyethylene plastic (so it would not expand and explode at high altitudes) two-thousandths of an inch thick, and carried a sealed, pressurized gondola called Stratolab with a crew of two. On 8 November 1956, Stratolab set a world record of 76,000 feet, higher than any humans had ever gone before without the assistance of a rocket.

Stratolab was an extension of two other ONR-funded projects, Helios and Skyhook, which had developed extreme high-altitude balloons in the late 1940s for atmospheric research. Stratolab’s mission was to extend research into the farthest reaches of the atmosphere, to a point where instruments pointed skyward could measure and observe phenomena in space beyond 96 percent or more of the atmosphere.

Stratolab put a variety of instruments into near-space, from coronagraphs for measuring the sun’s brightness to telescopes for observing the stars. The program’s ultimate success—an ascent to 113,740 feet on 4 May 1961—was overshadowed by both tragedy and triumph. After landing safely in the Gulf of Mexico, Lt. Cmdr. Victor Prather drowned when he fell from the recovery helicopter.

The next day, astronaut Alan Shepard became the first American in space when his Freedom 7 rocket reached an altitude of just over 101 nautical miles. Shepard wore the same Mark IV spacesuit that had been developed for and tested by Stratolab pilots.

The science behind Stratolab continued on, however. Its full realization began with a series of solar and astronomical observing satellites launched beginning in the 1960s, the most notable of which was the Hubble Space Telescope in 1990. The evolution of the observation of space from space will be carried forward even further with the James Webb Space Telescope, planned for launch in 2018.

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