NASA Puts Emphasis on Safety in Preparation for Next Launch

NASA engineers are putting the finishing touches on an elaborate new launch pad escape system that could save shuttle astronauts from a prelaunch catastrophe.

The work is part of a wide-ranging program to beef up safety at the Kennedy Space Center before Discovery’s launch on the first post-Challenger shuttle mission next June.

In addition to the launch pad escape program, engineers are working to determine whether lightning could set off a shuttle booster during the 3 1/2-mile trip from the rocket assembly building to the pad and, if so, what weather guidelines should be followed before allowing the shuttle to move.

6-Hour Trip to Pad

It takes about six hours for the shuttle atop a ponderous crawler-transporter to reach the pad. Before Challenger exploded last year, the move was allowed only if no lightning was expected in a circle roughly 12 miles across.

“You can predict up to six hours, which gives you time, but what happens if the crawler breaks down?” asked Gene Thomas, director of safety, reliability and quality assurance at the spaceport. “That’s happened to us before, and it takes a few hours to fix it. A storm could come in on you.”

He said engineers at the Marshall Space Flight Center in Huntsville, Ala., are conducting studies to determine whether a lightning strike during “rollout” could trigger ignition of a shuttle booster’s propellant.

On Jan. 11, 1985, three soldiers were killed and 16 injured in West Germany when a static electricity charge ignited the solid propellant of a Pershing-2 missile.

“The crawler crews said, ‘Hey! When we’re driving to the pad, we don’t have a ground that’s apparent. We know this thing is heavy and it’s touching the ground, but what would happen if lightning struck the top of the (shuttle’s external fuel) tank?’ ” Thomas said. “It’s an obvious question. Those are the kinds of things we’re talking about.”

While the lightning research is not yet complete, NASA is gearing up for tests of a beefed-up launch pad escape system to give shuttle crews a fighting chance in the event of a prelaunch emergency.

Astronauts board the shuttle at the 195-foot level of the launch pad gantry. On the side of the gantry away from the shuttle, large wire-frame baskets hang under cables that stretch 1,200 feet to the ground and a bunker west of the pad.

In the event of an emergency that required a quick escape, the astronauts would exit the shuttle, run across the gantry, jump in the baskets and make a dizzying descent to the underground bunker.

But tests conducted after the Challenger disaster prompted NASA to upgrade the system to improve safety. Two more baskets have been added for a total of seven, and each one can carry three people. Additional fire detectors have been installed on the gantry along with extra television cameras and fire protection equipment.

In the 25 previous shuttle missions, the escape system has not been needed. But on June 26, 1984, Discovery suffered a main-engine shutdown just four seconds before liftoff and a hydrogen fire broke out at the base of the orbiter.

“We opted, and I was part of that decision, to leave (the astronauts) in the vehicle,” Thomas said in an interview. “We thought we pretty well knew where (the fire) was. I can see a scenario where we’ve got that fire, and we’ve got a tank that’s fixing to blow.

‘It Could Happen’

“That didn’t happen, but I can see that it could happen. Then we’d say, ‘Get out of there and go to the baskets.’ We would not take the time to go down the elevator or the stairs.”

The new baskets feature several improvements for safer operations. Thomas said that after unmanned tests early next year, a three-person team will climb into a basket for a ride to the ground to verify the system’s operation.

“We’ll probably have one flight crewman, one close-out crewman and one fire rescue person,” Thomas said. “My requirement is going to be at least one basket with three people in it--that’s a normal load--and I think one astronaut for sure.”

The test is tentatively planned for early February.