For many years, scientists wanted to study the air above the earth. Then the Army Air Corps and the National Geographic Society got together. They built a balloon that could travel into the stratosphere. The stratosphere starts eleven miles above the earth. There are few clouds there but still enough oxygen to breathe. The air corps and the society picked a place near Rapid City to launch their balloon. It was a smooth hollow about five hundred feet deep. It was soon known as the Stratobowl. Men from the Civilian Conservation Corps and others worked hard to get the site ready.

Photo courtesy of South Dakota State Historical Society

     The balloon was called Explorer I. It made its first flight in 1934. The scientists riding in the balloon were able to take air samples. The balloon went up eleven and a half  miles. Soon the balloon started to break apart. The men had to jump out. They were wearing parachutes and made it safely to the ground. The balloon crashed and broke most of their equipment. They tried again a year later with Explorer II. This time they traveled even higher above the earth. They also wore football "crash" helmets from a school in Rapid City. The balloon landed safely near White Lake, South Dakota. Explorer II went nearly fourteen miles into the air. No one would fly higher until astronauts started flying into space.

     The scientists on the Explorer balloons learned a lot about the atmosphere of the earth. This helped the United States Air Force build better planes. It helped scientists build satellites. Today, you can still see the Explorer II at the South Dakota Air and Space Museum. The museum is at the Ellsworth Air Force Base in Box Elder, South Dakota.