NASA Pushes Next Shuttle Flight to Spring

CAPE CANAVERAL, Fla. - NASA has pushed the next space shuttle flight to no earlier than spring 2006, conceding that engineers need months more work on the fuel-tank foam problem that returned with a vengeance on July's Discovery launch.

The next mission, aboard Atlantis, had been targeted for a March window; agency officials now say even that is optimistic as technicians redesign the tank's foam ramp — the piece whose failure in flight brought the shuttle program to a halt barely two weeks after its celebrated return.

"We will fly when the tank is right and not before," a senior shuttle manager said. "Nobody at this agency needs another lecture on schedule pressure."

The July flight was supposed to close the book on the Columbia disaster. Instead, cameras captured a chunk of foam — smaller than the one that doomed Columbia but similar in kind — separating from the tank at ascent. The shuttle itself was unharmed, but the fleet was grounded anyway.

Engineers have spent the weeks since dissecting the tank, section by section, at the Michoud Assembly Facility in New Orleans — work that proceeded even as Hurricane Katrina scattered the plant's own work force and flooded parts of the city around it.

Michoud escaped major structural damage, and NASA says tank work has resumed, but the storm cost the program weeks. Some of the facility's 2,000 workers are living in trailers and commuting from out of state.

The three shuttles' fate is tied to a 2010 deadline: the agency plans to retire the fleet then and shift to a new crew exploration vehicle, leaving roughly 18 flights to finish the International Space Station.

Each slip compresses that math. "The station doesn't build itself," one official said. "But a foam answer you have to give twice is no answer at all."

The Discovery crew, meanwhile, has been touring the country with the flight's photographs — including the unprecedented spacewalk repair in which an astronaut plucked protruding filler from the shuttle's belly by hand.