Shuttle Crew Stages Mock Emergency Landing

Three space shuttle astronauts made a mock emergency landing Tuesday during a comprehensive launching rehearsal that tested hundreds of changes resulting from the Challenger explosion.

The practice session for the nation’s first shuttle mission in 2 1/2 years, scheduled for late August, put the launching team here and flight controllers in Houston through the final three hours of a countdown and the minutes of a failure requiring split-second decisions.

Astronaut Bob Crippen, deputy director of shuttle operations, who will make the final decision on whether a shuttle should be launched, said the test pointed up a few areas in problem-solving that needed to be improved, but “all in all, it was an excellent exercise.”

Challenger’s seven crew members died when a faulty booster rocket caused their spaceship to explode on Jan. 28, 1986. With the two boosters still attached and burning, the crew had no chance to escape.

Abort Maneuver

The simulated failure Tuesday of two of the three main engines occurred seconds after the boosters “burned out” normally and were jettisoned, enabling the three astronauts, operating in a Houston simulator, to execute an abort maneuver called “return to launch site,” or RTLS.

“We think we’ve lost the left engine,” astronaut Loren Shriver, the simulator commander, told mission control about two minutes after the pretend liftoff.

“Discovery, we confirm the left engine is down. Abort RTLS,” the control center radioed.

Shriver and his crew members, James Wetherbee and Franklin Chang-Diaz, “flew” the simulator to an altitude of about 75 miles and 400 miles out over the Atlantic Ocean to exhaust hundreds of thousands of gallons of fuel.

With a second engine now “locked up and useless,” the astronauts pitched around, went through the motions of jettisoning their huge external fuel tank into the ocean and, battling hydraulic and other difficulties, glided to the make-believe touchdown on a runway three miles from the launching pad. Landing occurred 21 minutes after the abort maneuver began.

Because of the Challenger accident, the National Aeronautics and Space Administration has introduced hundreds of changes, most aimed at safety, into the launching process. The changes include new procedures, management responsibilities and ground and flight hardware and software.