High Altitude Balloons

In 1954, the Office of Naval Research (ONR) began the Strato-lab training program for manned balloon ascents to the upper atmosphere. On November 8, 1956, Malcolm Ross and M. L. Lewis ascended to 76,000 feet (23,165 meters) under the first plastic 2,000,000-cubic-foot (56,634-cubic-meter) balloon. Using a two-million-cubic-foot (56,634-cubic-meter), 172.6-foot (52.6-meter) diameter balloon and a cramped aluminum alloy capsule manufactured by Winzen Research of Minneapolis, Kittinger made the first Man High ascent on June 2, 1957. At sea level, it was 35 to 40 feet wide and 200 feet high; at altitude, due to the low air pressure, it expanded to 25 stories in width, and still was 20 stories high.

During the Cold War, balloons were used to collect data on atmospheric radiation levels. The Atomic Energy Commission's Project Ash Can, with some co-sponsorship by the Advanced Research Projects Agency (ARPA), monitored radioactivity in the environment. Launched in 1956, Ash Can used polyethylene balloons designed by Otto Winzen to collect particle samples in the stratosphere. These samples were tested for the presence of radioactive dust raised by nuclear blasts and nuclear bomb tests.

As part of the Stratoscope program, a series of three 10-million-cubic-foot (283,169-cubic-meter) Winzen balloons were launched from the deck of the Valley Forge aircraft carrier in the Caribbean starting on January 26, 1960. These huge thin-film polyethylene plastic balloons lifted cosmic ray research equipment weighing two tons (1,814 kilograms) for the National Science Foundation (NSF) above 100,000 feet (30,480 meters).

On May 4, 1961, U.S. Navy Commander Malcolm Ross and Lieutenant Commander Victor Prather set an altitude record of 113,740 feet (34,668 meters) on a flight launched from the U.S. Navy aircraft carrier Antietam over the Gulf of Mexico. Part of the Stratolab project, Ross and Prather ascended in the largest balloon ever used on a manned flight up to that time. They reached their maximum altitude two hours and 36 minutes after takeoff. Their achievement was marred, however, by the death of Prather, who fell from the sling of the recovery helicopter and died on board the carrier about an hour after being pulled from the water.

Manhigh II weighed in at 1,648 lbs. The balloon that carried it to 101,516 ft would expand to a diameter of 200 ft, with a volume in excess of 3,000,000 cu. ft. Manhigh II, on Aug. 19, 1957. Manhigh II reached the highest altitude of the program, at 101,516 ft-establishing a new altitude record for manned balloons.

Project Stargazer, a 2-man observatory carried to very high altitudes by a helium-filled mylar balloon that was 400 ft tall at launch, but flattened out and expanded to a diameter of 280 ft at altitude. On Dec. 13-14, 1962, Joe Kittinger and astronomer William White rode Stargazer to 82,000 ft over Holloman AFB. At a volume of 10 million cubic feet (283,169 cubic meters), Strato-lab V was the largest human-piloted balloon ever flown and set an altitude record that still stands - 113,740 feet (34,668 meters). The pilots wore suits being tested for the Mercury astronauts.

By 1972, the largest balloons had a 53-million-cubic-foot (1.5-million-cubic-meter) capacity, measured 750 feet (229 meters) tall, had 24.8 miles (40 kilometres) of heat-welded seams, and could carry seven tons (6,350 kilograms) of instruments to low altitudes or lighter packages to 31 miles (50 kilometres).