Balloons on a Mission

When scientists need to do research at the very edge of space, they skip the rocket ship and send a balloon instead.

NASA researchers use balloon flights to do scientific experiments or test out equipment for future space missions. At 21 to 25 miles (34 to 40 kilometers) in the air, where these balloons fly, Earth's atmosphere is extremely thin. This means equipment on board the balloon can get a clear view of outer space.

"The super-pressure balloon technology is a real game-changer for conducting cutting-edge science at the end of space," says Debbie Fairbrother. She heads NASA's Balloon Program Office in Virginia.

These scientific balloons are made of a thin plastic film that's just 0.0008 inches (0.02 millimeters) thick. Called polyethylene, it's similar to sandwich wrap. But that flimsy-looking skin stretches around an enormous volume of air. The most common balloons flown by NASA are 40 million cubic feet in volume-equal to 195 Goodyear blimps. These balloons are about 40 stories tall. NASA also launches balloons that are smaller than this, or even larger.