Dec. 7, 2004 — NASA is counting on a series of preventative measures to get the space shuttle back into flight after the Columbia tragedy in 2003, including tight limits on fuel tank debris shedding and aggressive in-flight vehicle inspections.

However, the ability to make repairs in orbit likely will fall short of what would be needed to fix holes in the shuttle's heat shield or wing panels if they were discovered after the shuttle left Earth, NASA managers said Monday.

Columbia was destroyed and its seven crew members killed during re-entry into the atmosphere because of a hole in the ship's wing. The breach was caused by foam falling from the shuttle's fuel tank during launch.

"We are making strides," said shuttle program manager Bill Parsons. "We think we will have some techniques to test in orbit, but I can tell you I will be very, very surprised if we have a certified repair technique" in place before the first post-Columbia mission.

That flight remains targeted for launch between May 12 and June 3, 2005.

Managers said in-orbit repairs are proving more difficult to perfect than originally expected. Experiments slated to be conducted in the weightless environment of space during the Discovery mission are a key step in developing the technology and procedures. But an actual, proven in-orbit repair capability is probably years away, Parsons said.

The shuttles' days are numbered already. NASA is preparing to retire the fleet in six or seven years, once construction of the International Space Station is complete.

An orbital repair capability is among the 15 prime recommendations of the Columbia Accident Investigation Board. NASA, however, said that does not mean not having a repair kit will prevent the shuttle from flying.

"It is not a requirement," Parsons said. "The CAIB (Columbia Accident Investigation Board) said to do the best that we could to come up with some technique to repair RCC (reinforced carbon-carbon panels on the wing leading edge) and repair tile. We have done that. We have continued to put the best and brightest this agency has to offer on this.

"We've used every resource this agency and this nation has to work on this. We've made a lot of progress. There are some issues that we still need to resolve."

In addition to an improved shuttle fuel tank and in-flight inspection techniques, NASA has developed plans for astronauts to evacuate to the space station in case they cannot safely return to Earth in their ship.

The lesson of the Columbia accident, added Wayne Hale, a former flight director who now heads NASA's mission management team, is to always have options.