In 1960, the U.S. Military put the Convair B-58 supersonic jet into service but they had a problem, it had standard ejection seats in it and at supersonic speeds and at high altitude, that meant there was good chance the crewman would not survive the extreme conditions. The military had to come with a better idea, so they worked with Stanley Aircraft to develop an ‘escape capsule’, and they did. One problem, who to test it on?

The solution was to put a bear in the ejection capsule to see if it worked. In March of 1962 a female bear name Yogi was strapped in and taken for a ride at a speed of 870 mph. At 35,000 feet Yogi was ejected and about 8 minutes later the bear and the capsule touched down safely.

About two weeks later they tried it again using a male bear named ‘Big John’ but this time the went higher, 45,000 feet, and faster, 1,000 mph, and again, the bear landed safely. The reason the bears where used was because they most accurately represented the weight of a pilot.

Airpigz.com