Repair Efforts Continue on Atlantis Shuttle's Dinged Fuel Tank

In Highbay 1 in the Vehicle Assembly Building, the space shuttle Atlantis' orbiter cockpit, nose cone and part of the external tank peak through various levels of scaffolding as work continues to repair the external tank. CREDIT: NASA/Jack Pfaller.

Engineers continue to work feverishly to repair the hail-damaged fuel tank of NASA's Atlantis shuttle in time for a mid-May launch, though space agency officials are still unsure whether a replacement may be required.

"We still don't know which tank we'll use for STS-117," William Gerstenmaier, NASA's associate administrator for space operations, told a senate subcommittee this week of Atlantis' mission. "We can still potentially make the May launch window if we use this tank, if we don't we'll be in the June time frame."

NASA officials have said that Atlantis could launch between mid-May and May 21 if the shuttle's fuel tank repairs, and a subsequent analysis, go well. Replacing the tank with a new one would push the spaceflight to no earlier than June 8.

NASA is expected to set a new launch target for Atlantis' STS-117 mission to the International Space Station (ISS) on April 10.

The shuttle and its six-astronaut crew were preparing for a planned March 15 liftoff from NASA's Kennedy Space Center (KSC) in Florida when a severe storm battered the orbiter's foam-covered fuel tank with golf ball-sized hail on Feb. 26.

The resulting damage left thousands of dings in the vital foam insulation on Atlantis' external tank, which engineers have been sanding smooth and repairing inside NASA's cavernous Vehicle Assembly Building at KSC. Of the more than 2,500 dings in the fuel tank, some 1,600 may require repair, NASA officials have said.

"It's going to be very challenging," George Diller, a NASA spokesperson at KSC, told SPACE.com of the time-consuming repair work. "There's a lot of work to do, but it's achievable."

A new shuttle fuel tank, originally built for NASA's STS-118 shuttle flight but which could be used for STS-117, will be shipped on Sunday or Monday from the agency's New Orleans-based Michoud Assembly Facility, NASA officials said. It will arrive two days earlier than expected at KSC in Cape Canaveral, Florida, they added.

"We're expecting the next tank on [April] 8 if they don't run into weather that slows them down en route," Diller said. "However, that is not going to speed the decision process any...the tenth is still decision day."

Gerstenmaier said that it will be the repair work's progress that will dictate when shuttle mission managers will target Atlantis' launch date.

"We're letting the work kind of drive the activity," Gerstenmaier said. "We're not picking the launch date and then forcing the work to fit into that launch date."

Commanded by veteran shuttle flyer Rick Sturckow, NASA's STS-117 mission is the first of several ISS construction flights scheduled for 2007. The 11-day flight features three planned spacewalks to install two new trusses and solar arrays to the station's starboard side.

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