Problems, defects plagued Columbia's space missions

By Mary Pat Flaherty and Sara Kehaulani Goo, Washington Post, 2/23/2003

or years before it broke apart in the skies over Texas, the space shuttle Columbia was beset by recurring problems, glitches, and close calls.

In 20 of its 28 missions, the first in 1981, Columbia experienced mechanical or technical problems at launch or in orbit. Those problems caused Columbia to have more flight delays than any other orbiter, according to a review of thousands of pages of NASA documents and interviews.

While nobody is yet sure what caused Columbia's catastrophic ending this month, between 1996 and 1999 the orbiter had at least five ''escapes'' - a NASA term for a mission that flew with a problem that only ''luck or providence'' prevented from causing serious damage. On another launch, a worker made what NASA calls a ''diving catch,'' meaning his diligence caught a flaw that routine checks had missed.

For more than a decade, as inspectors tried to keep Columbia on schedule, they granted waivers from required maintenance, 350 pages worth. Since Columbia was the oldest orbiter in the fleet, NASA also relaxed maintenance standards, an acknowledgment that an old machine cannot perform as well as a newer one.

But those changes were made without an assessment about whether the adjustments heightened risk. A safety panel looking at Columbia's wiring problems in 1999 concluded that the issue may have contributed to Columbia's narrowly avoiding an emergency landing.

For all the bold thinking that brought forth Columbia, the shuttle program has experienced financial pressure, the loss of skilled workers, and maintenance challenges. Numerous outside reviews have concluded there are systemic weaknesses in the shuttle program that go deeper than the mission-by-mission problems.

As NASA ponders how to recover from its second shuttle catastrophe in slightly more than 100 flights, it has become clear that manned space flight remains a far riskier undertaking than the program's architects had envisioned. Each of the remaining shuttles - Discovery, Atlantis, and Endeavour - will face questions about its maintenance record and safety history. NASA is confronting increasing pressure to find a better successor vehicle to the shuttle.

NASA staunchly denies safety has slipped, even as outside audits and reviews noted items - including the hundreds of maintenance waivers or reduction in quality checks - that point to troubling systemic problems.

William Readdy, NASA's associate administrator for space flight, said, ''I think you would have to look at each of those individually,'' to understand them, but as a general matter NASA has a safety ''culture'' that extends from the top down to its smallest vendors.

''We are anything but complacent,'' said NASA administrator Sean O'Keefe.

The care NASA takes in its programs, O'Keefe added, may have lulled the public into forgetting that space flight is risky.

Details from Columbia's missions demonstrate that.

As a five-man crew slept in January 1990, Columbia flew out of control for 15 to 20 minutes when the automatic pilot received bad navigation data and fired thrusters. Mission Control woke up the commander, who righted the shuttle.

Three seconds before liftoff in March 1993, an engine failed to ignite, aborting the launch. All three of Columbia's engines had to be replaced.

In June 1996, the Columbia flew with damaged and exposed wires that should have been discovered before liftoff, and on the 1999 flight with wiring problems, Columbia suffered a power drop that put it 7 miles off its intended orbit.

Columbia bore the signs of how bruising flight can be. The shuttle took 1,239 hits from unknown debris on its protective ceramic tiles between 1995, just after a major upgrade, and the summer of 1999, just before its last overhaul, according to a Washington Post review of mission reports. The tiles shield the orbiter from scorching heat during reentry. Of the 1,239 hits, 217 caused damage larger than an inch on Columbia's lower side, the section most exposed during reentry. Tiles were repaired and replaced after those missions.

Columbia was also the most refurbished shuttle. Its improvements and maintenance mean ''the age of this asset is something of a deception,'' O'Keefe said.

Each shuttle undergoes an overhaul after eight to 10 flights, a process O'Keefe describes as tearing it down to the frame and reconstructing it. Columbia's last major upgrade, finished in early 2001, took 18 months and cost close to $160 million.

Designed to fly 100 missions overall, Columbia was on its 28th when it disintegrated, far below the expected limit on metal fatigue and in-flight stresses. But it also had been 24 years since the first piece of aluminum alloy was cut for Columbia. The ambitious schedule NASA predicted for its shuttle fleet early on - 50 flights a year, not the four or five it was achieving - would have had Columbia logging its maximum missions at a much younger age.

This story ran on page A8 of the Boston Globe on 2/23/2003.
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