The timing of NASA’s next shuttle launch remains uncertain as the space agency works to recover key facilities from the aftermath of Hurricane Katrina, agency officials said Sept. 8 .

Hurricane Katrina damaged NASA’s external tank-producing Michoud Assembly Facility in New Orleans, as well as nearby Stennis Space Center, Miss., where shuttle main engines are tested .

While some NASA officials still hope to launch around March 2006, they were unable to complete a feasibility analysis for that target before the hurricane struck the Gulf Coast Aug. 29 .

“We’re in the process of evaluating it,” William Gerstenmaier, NASA’s associate administrator for space operations, said of a possible spring launch during a teleconference with reporters.

The update followed reports of an internal Sept. 1 memo by Wayne Hale, NASA’s deputy shuttle program manager, in which he suggested that “launch dates before fall [2006] may not be credible.”

Even before Katrina, launching again before June was unlikely given all NASA has to do to prepare for the next flight, Hale wrote.

“Right now, we’re still addressing what the implications are on the shuttle launch schedule, and if I say I don’t know what those are, that’s an understatement,” NASA Administrator Mike Griffin told employees in a televised address, according to the Associated Press.

Gerstenmaier said Hale’s note — a copy which was obtained by Space News — was a very preliminary paper used to discuss some of the initial points raised by the hurricane.

“It’s really too difficult to predict” future shuttle launch dates, Gerstenmaier said.

NASA has estimated it will need about $1.1 billion – $500 million for Michoud and $600 million for Stennis – to aid recovery efforts at the two sites, Gerstenmaier said. But those were preliminary damage estimates based on photographs, and NASA’s past experience with hurricanes at Kennedy Space Center in Florida, he added.

In addition to damage at both facilities, up to 900 people who work at Stennis have lost their homes, said William Parsons, NASA’s space shuttle program manager, who is spearheading the agency’s hurricane relief effort. Almost 4,000 people were evacuated to Stennis Space Center when Hurricane Katrina hit, he added.

All of the Stennis center’s civil servants have been accounted for, as well as 95 percent of its contractor personnel, Parsons said, adding that Lockheed Martin is still tracking down about half of its 2,200 employees at Michoud. The 15 NASA employees stationed at the New Orleans facility have been accounted for, he added.

NASA’s next shuttle flight depends on when engineers solve a foam-shedding problem observed during the July 26 launch of the Space Shuttle Discovery.

A half-kilogram piece of foam insulation fell from a protective ramp on Discovery’s tank during launch. While that chunk of foam did not strike Discovery, a similar shedding event did strike the Space Shuttle Columbia during its ill-fated 2003 launch. Columbia’s heat shield was damaged in the impact, and the shuttle broke apart during re-entry, killing its seven-astronaut crew.

NASA engineers are still unsure of the exact cause of the latest foam loss, but have narrowed it to a few potential sources, shuttle officials said.

“It looks like it’s going to be very unlikely that we’re going to be able to just remove the … ramp and fly,” Gerstenmaier said.

Some tank studies are under way at Marshall Space Flight Center in Huntsville, Ala. , while other non-destructive analysis work likely will be moved from Michoud to Kennedy while the New Orleans facility rebuilds, Gerstenmaier added.

Conditions are improving daily at Michoud and Stennis, though recovery teams only recently have managed to reach the external tank facility by road, NASA officials said. The facility previously was accessible only by helicopter, they added.

Michoud suffered roof damage when Hurricane Katrina struck, including the external tank storehouse. One tank was damaged when concrete, knocked loose in the storm, hit it, Parsons said.

“We haven’t been able to evaluate that damage,” Parsons said, adding that cursory looks suggest it’s superficial. “We’re trying to safe the facility.”

A tornado damaged some roofs at the Stennis center, but overall the facility fared “very well,” Parsons said.