In the situation where a space shuttle orbiter is in a controlled (level) gliding flight
yet unable to reach the runway for one reason or another, there is a orbiter system designed to give some chance of survival to the flight crew.
Using the Inflight Crew Escape System, the flight crew would blow the side door hatch and then deploy a pole that extends from the inside of the orbiter out and down (with respect to the orbiter as a glider). This angle of the pole provides astronauts a trajectory that will take them under the left wing. Space suits attach to this pole and allow the astronaut to slide out away from the orbiter and then parachute to safety.
The procedure for using the Inflight Crew Escape System is:
- At 30,000 feet, the airspeed is decreased to 230 mph (200 knots).
- At 25,000 feet, the autopilot mode changes the angle of attack to 15 degrees. This remains for 3 minutes at which point the orbiter should be at an altitude of 2,000 feet
- At 25,000 feet the jump master jettisons the side hatch
- In practice runs, it takes about 90 seconds for a crew of eight to bail out (12 second intervals). This process finishes at about 10,000 feet altitude.
With respect to the Challenger, this system would not be usable, even if it was installed (the Challenger explosion prompted the modification). Only a short time into the flight, the shuttle was not on a glide path, but rather was in effect a missile in a balistic path. In this case, the shuttle would follow the Return To Launch Site which may occur prior to 4 minutes, 20 seconds into flight. After this time, there isn't enough fuel to do this emergency landing and a Trans-atlantic Abort Landing would be undertaken in which case the shuttle would land either in Moron, Spain; Dakar, Senegal; or Ben Guerur, Morocco. With the Challenger, none of these options were possible.
The Columbia broke up at about 207,135 feet - on the order of 10 times higher than the standard procedure for use of the Inflight Crew Escape System. The Columbia was originally fitted with a ejection seats - used in the first 4 flights (only two crew were on board). The upper envelope of the ejection seat was 100,000 feet. The seats were removed to make room for larger crews after STS-4. The configuration of where people sits prevents more than two ejection seats in any case. Do realize, that specially designed suits are required for skydiving from 100,000 feet; and the current record is 102,800 feet by Joe Kittinger set in 1960. (see skydiving for more about the records and problems with such dives.)
(A fiction story about an orbital to land skydiving from STS-106 can be read at: http://people.qualcomm.com/billvon/fiction/orbit.html)