Nicole Watch

Astronauts practice escaping today. The astronauts spent Thursday getting familiar with the launch tower escape system. The system comprises seven metal baskets that would zip down a 1,200-foot slidewire to a bunker on the outer perimeter of the launch complex.

Today, the astronauts will don partial-pressure launch-and-entry suits and ride an elevator up to the 195-foot level of the launch tower. They’ll then enter the orbiter Discovery and strap into seats. NASA’s shuttle launch team will conduct the final hours of a practice countdown.

Countdown clocks will come to a halt at T-minus 4 seconds. The launch team will simulate a main engine shutdown and the astronauts will go through an emergency escape drill. They climb into the baskets, which also are on the 195-foot level of the tower, but they will not ride down the slidewire.