Safety questions remain in wake of shuttle tragedy

WASHINGTON – Two years ago today, the shuttle Columbia disintegrated on its way back to Earth, killing all seven astronauts and shattering confidence in NASA’s system of safety checks and balances.

After that stunning tragedy in the skies over Texas on Feb. 1, 2003, NASA grounded its remaining fleet of orbiters and worked to ensure there never again would be such a fatal safety breach.

The result: When Discovery blasts off from Kennedy Space Center – as early as mid-May – the maze of decisions behind the final “go” call will have changed dramatically.

Discovery will be a safer vehicle, thanks to the improvements made since the accident. But the key question as NASA moves forward is how the agency will ensure that no one relaxes its newer, stronger safety rules – the kind of erosion that marked the period between the 1986 Challenger accident and the loss of Columbia.

The first part of the answer is NASA’s new expanded safety net, which is designed to hand direct responsibility, and accountability, to experts within the shuttle program. They report to the chief engineer, who has a direct line to the agency’s administrator. Together, they can stop work on a particular component, and ultimately stop a launch altogether.

This new, internal oversight system is independent of the shuttle program, both in power structure and in budget.

But flying is the ultimate test of all of the changes, said John Logsdon, director of the Space Policy Institute at George Washington University and a member of the outside board that investigated the Columbia accident. The tough part is making sure the changes stick.

At the recommendation of the special accident board, NASA moved to create a network of people, now called “warrant holders,” responsible for each part of the complex shuttle machinery. These people will have the power to flag a potential problem and stop work while they seek to understand and fix it – and shuttle managers can’t stop them because of budget or schedule issues.

On the second-to-last mission before Columbia, a chunk of foam flew off the external fuel tank during Atlantis’ ascent and struck the rocket booster. Some engineers at NASA expressed concerns that the foam could present a safety issue in future launches. However, at the final pre-flight meeting for the next shuttle launch – on Endeavour – top NASA officials discussed the foam problem and decided it was safe to launch. The subject didn’t even come up before Columbia’s final flight.

The Columbia tragedy occurred because a briefcase-size chunk of foam broke apart from the external fuel tank during launch and hit the outer edge of the left wing, allowing hot gases to breach the wing during re-entry and break apart the shuttle.

In the future, NASA spokesman Dave Steitz said, the new technical authority would be involved from the first reports of a problem such as foam, studying the issue and weighing in on whether it would be safe to fly.

Also lending assistance could be the NASA Engineering and Safety Center, which is headquartered at Langley Research Center in Virginia. The center, which is open to inquiries from programs all over NASA, is a group of engineers who are there to scrutinize problems.

But while the intense scrutiny NASA has experienced over the past two years will surely last through the first couple of flights, inevitably it may fade, just as it did in the years after Challenger.

And the pressure to fly will be at least as intense as it’s ever been – with the retirement of the shuttle fleet hinging on the completion of the International Space Station and a schedule of roughly 28 shuttle flights before the end of the decade.

That’s where another key safety group – the revamped Aerospace Safety Advisory Panel – comes in. The panel is charged with changing the agency’s safety culture.

Joe Dyer, the retired vice admiral who now heads the panel, said the group will keep watch on the amount of money NASA requests and receives for all of the agency’s safety organizations.