This would be a very, very bad day

Seven astronauts scrambled out of shuttle Discovery this week, capping a practice countdown with a launch tower escape drill.

Engineers in the NASA Launch Control Center staged a main engine shut down a scant four seconds prior to a would-be launch, triggering a crew cabin escape drill for the five-man, two-woman Discovery crew.

Clad in 70-pound partial pressure spacesuits, the astronauts exited Discovery at the 195-foot level of pad 39B and then scurried across an orbiter access arm before dashing to a slidewire basket system on the west side of the gantry.

The astronauts climbed into the baskets, but stopped short of riding them down a 1,200-foot metal slidewire to an emergency bunker on the western perimeter of the pad.

The evacuation drill was aimed at preparing the astronauts for a fire, explosion or other emergency at the pad on launch day.

Here's hoping the training is never put into practice.

Image note: Click to enlarge the NASA image of two Discovery astronauts scrambling off the orbiter access arm and heading for launch tower escape baskets at the end of a practice countdown Thursday. Photo credit: NASA/Kim Shiflett.