NASA knew of shuttle's 1,600 flaws

Published on Monday 23 June 2003 01:00

NASA launched the space shuttle Columbia aware that it had more than 1,600 potentially fatal technical flaws, an inquiry into the accident has found.

The revelation provides new evidence on the extent of NASA’s risk-taking, exposing how the space agency regularly diced with disaster rather than fix known problems.

It also shatters NASA’s hopes of returning the three remaining shuttles to service by next January, and will increase repair bills by millions of dollars.

The Columbia Accident Investigation Board, an independent 13-member panel, is writing its final report into the shuttle’s break-up on 1 February, which killed all seven astronauts aboard. It is expected to ask NASA to review thousands of "waivers", which allowed the spacecraft to fly despite the existence of known defects, most of them minor.

The leading theory on the cause of the disaster is that the left wing was damaged by falling debris during lift-off, allowing super-hot gases to seep inside the craft during re-entry.

However, the inquiry has also found critical weaknesses in NASA’s management culture. The "waiver" system is seen as a particular problem.

NASA engineers can recommend the acceptance of a certain element of risk, thereby allowing the shuttle to fly with a known defect, especially if fixing the problem could involve a lengthy redesign. Waivers can cover minor or serious flaws. If an engineer is unable to trace the batch number of a spare part, as required by NASA rules, then a waiver must be granted, even though there is no safety issue.

But waivers can also be granted for problems with the fuel tank or the engines.

Internal NASA documents obtained by the Florida Today newspaper show that 5,800 waivers had been granted to Columbia by the time of its launch on 16 January.

Of those, 1,672 involved critical parts, the failure of which could have fatal consequences. They included 652 waivers on the orbiter itself, 312 on the main engines and 163 on the external fuel tank.

"There is no systematic effort to attempt to deal with all the waivers that have been granted," said Sally Ride, a former shuttle astronaut and member of the accident board.

Ms Ride also served on the commission that investigated the 1986 explosion of the space shuttle Challenger. That shuttle was found to have been flying with 829 so-called "Criticality 1" waivers, including one relating to the rubber seals on the booster rocket, later found to have caused the Challenger disaster. That commission criticised NASA’s "excessive" waiver system.

In its final report, the Columbia inquiry board will also cite "excessive waivers" as a factor that contributed to the latest disaster. It will call on the space agency to address each one before returning the remaining shuttles to service.