To use it, an astronaut first would don a spacesuit and remove the 200-pound (90-kilogram) packaged escape system from a large suitcase-sized container aboard the spacecraft.

Then the person would unfold a 6-foot- (1.8-meter-) long bag made of clear Mylar plastic and step into one end of it.

Attached and bonded to the rear of the bag was an ablative heat shield about one-quarter inch (6.3 millimeters) thick. Inside the bag were two canisters of white polyurethane foam, a portable rocket motor with twin exhaust nozzles that protruded through the Mylar cover, a parachute, radio equipment and a survival kit.

Once inside the bag, the astronaut would don a harness, zip the bag closed and float out the hatch of the spacecraft.

Out in space the astronaut would activate the foam canisters, which would inflate the bag into the shape of a blunt cone within a few minutes.

Then the astronaut would orient the bag with the rocket motor so that the blunt end faced towards Earth. That way, atmospheric heat upon reentry would char only the heat shield.

Once the bag fell to 30,000 feet (9,145 meters) above Earth's surface, an on-board barometer would automatically deploy a parachute.

The parachute then would slow the bags speed to around 25 feet (7.6 meters) per second, slow enough to survive impact on land or water. The bag was designed to float in water.

On the way down, the bag's radio beacon would send signals to help rescue teams locate and recover the astronaut.