MIAMI – After two years of work and more than $1.5 billion in modifications, the space shuttle and its crew still could be endangered by the same debris problem that destroyed Columbia, NASA conceded Friday as it again delayed the spaceship’s return to flight.
Officials announced that shuttle Discovery, on the launchpad and scheduled for liftoff May 22, will be rolled back 4.2 miles to the hangar for additional repairs to its huge external fuel tank. The mission to test new safety measures and deliver supplies to the International Space Station will be postponed until at least July 13.
NASA’s top administrator called the delay “another routine launch slip,” but others wondered why the latest problem wasn’t identified and corrected before Discovery was on the pad. Many outside observers and some NASA engineers fear that the agency is rushing the shuttle back to space.
“With all the work we have done with the tanks over the years, especially the post-Columbia analysis,” said former astronaut Winston Scott, “it is amazing to me how it wasn’t flagged until just now, the 11th hour, sitting on the pad.”
At the same time, he praised NASA for what he called its continuing – though sometimes “toe-stubbing” – dedication to safety.
The main issue again is debris – in the form of foam insulation or shards of ice – that could break off the fuel tank during launch and inflict catastrophic damage on the orbiter, the airplane-like component that will carry Discovery’s seven astronauts.
The February 2003 loss of Columbia and its seven crew members was caused by a suitcase-size, 1.67-pound piece of foam that came loose and punched a hole in the left wing.
The New York Times reported last week that some NASA engineers believe the agency has loosened its standards concerning the acceptable risk of danger from such debris. They said NASA was searching for ways to justify returning the shuttle to space and was having trouble meeting safety goals set by an independent review board. NASA officials denied the assertions and said their latest action proves they are trying to reduce risks.