Is the shuttle safer?


After 2 years of work, dangers remain as Discovery's July 13 liftoff nears.

July 3, 2005|By Michael Cabbage, Sentinel Space Editor

CAPE CANAVERAL -- NASA spent more than two years and $1.1 billion to make sure the space shuttle is safe enough to fly again.

How safe is it?

It's as safe as any 20-year-old ship that has 2.5 million parts, hurtles to orbit atop an 8 1/2-minute controlled explosion and zips through the airless vacuum of space faster than a rifle bullet.

"This is a very risky venture," NASA Administrator Michael Griffin reminded agency employees at a town-hall meeting Tuesday. "The people who are doing this are risking their lives in support of objectives that the United States has in the pursuit of space exploration."

For Griffin, as well as many experts inside and outside of NASA, the pivotal question becomes: Is the shuttle fleet safer today than it was before Columbia broke up over Texas while returning home on Feb. 1, 2003?

The answer is a definitive "yes." The shuttle, in fact, is safer than it has ever been. For the crew members of the Discovery, which is scheduled to launch from Kennedy Space Center on July 13, that makes their mission a risk worth taking.

Shortly after the disaster, the Columbia Accident Investigation Board, or CAIB, coined the phrase "breaking the chain." That has been NASA's focus ever since -- to make sure the chain of events that led to America's second shuttle disaster never happens again.

Those events are well-known: A chunk of Styrofoam-like insulation fell from Columbia's external fuel tank during launch and hit the left wing. Vulnerable heat shielding on the wing was damaged. Unsuspecting crew members had no way to inspect their ship in space or make repairs.

Had any one of those things been different, the deaths of seven astronauts might have been averted.

In an exhaustive investigation of the accident, the CAIB criticized NASA for not recognizing the danger posed by launch debris or doing enough to protect the shuttle.

One of the space agency's toughest critics, CAIB chairman and retired Adm. Harold Gehman, now looks back on NASA's two years of work since the disaster and reacts with cautious approval.

No, NASA did not meet the letter of all 15 CAIB safety recommendations for returning to flight, he acknowledged Friday. However, he said, it made tremendous progress and reduced the risk enough to justify Discovery's launch.

Does that mean the shuttle is safe to fly?

"I'm sure that this next flight will be safer than the previous ones," Gehman said.

"But by any measure of `safe,' this is not safe."


When NASA received the CAIB's final report on Aug. 26, 2003, it quickly became clear that meeting some of the board's recommendations would be tough.

Few understood just how tough.

In an effort to give the shuttle program flexibility, the accident board described the recommendations as interrelated. It wasn't necessary to completely break every link to break the chain. The disaster happened because the tank shed foam, the orbiter's heat shielding was damaged and the crew had no way to inspect or fix the problem.

The CAIB made three key recommendations designed to specifically address those causes: Eliminate all dangerous debris shed by the tank, harden the space plane's heat shielding to make it more impact-resistant, and develop a means of inspecting and repairing the ship in orbit.

"The intent of our recommendations was to break what we considered a closely coupled cause-and-effect relationship between the inadvertent creation of debris at launch and the killing of astronauts," Gehman said. "That chain has a lot of links in it and it can be broken in many places. What we wanted NASA to do was to go after all the links at the same time."

Not surprisingly, the three links considered the most critical also presented the biggest challenges. Complicating matters was a deep division within an advisory group formed by NASA in 2003 to monitor the space agency's progress.

Headed by former astronauts Thomas Stafford and Richard Covey, the group's majority decided to hold NASA to a high standard based on a literal reading of the recommendations. Efforts to interpret the wording and uncover the CAIB's precise intent sparked the sort of debate usually reserved for the U.S. Constitution and religious texts.

"Admiral Gehman told me that they [NASA] should do the best that they could to develop the capabilities, go fly and continue developing the capabilities for the future," Covey said. "But you don't get that from the words."

The Stafford-Covey Task Group wrapped up two years of work Monday by concluding NASA failed to fully meet what were arguably the three most critical recommendations.

Group members decided it was better to rely on the actual wording of the recommendations than on Gehman's interpretation to Covey and others.

"Quite honestly, it's easier to come down on the side of a strict interpretation that was not met than to measure performance against a lesser standard and be subject to criticism that we didn't grade NASA hard enough," Covey said.


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