NASA’s latest launch delay for the Space Shuttle Discovery could push the orbiter’s final mission into the Christmas holiday, or even postpone it until February, agency officials said Nov. 24 following a review of recent repairs to Discovery’s external fuel tank.

Based on the discussion, NASA officials decided to forgo any launch attempts until at least Dec. 17, if not into the next launch window in February.

“What we’ve told the agency leadership is that clearly we’re not ready for the Dec. 3 to Dec. 7 window that’s coming up next week,” John Shannon, NASA’s shuttle program manager, said in a news conference. “We’ll leave the option open for a launch window for Dec. 17, but a lot of data has to come together to support that.”

A mid-December launch would push Discovery’s planned 11-day spaceflight into the Christmas holiday, something NASA has typically worked to avoid. The agency tries to not schedule any shuttle flights over the Christmas and New Year’s holidays, because shuttles in orbit when the year changes would need a flight computer reconfiguration, shuttle managers have said.

If NASA is unable to launch Discovery in December, the next clear chance to do so would come in February.

Shannon said engineers are concerned primarily with understanding the issues and evaluating the risks, and are less concerned with setting any definite launch dates.

Discovery’s STS-133 mission will be the shuttle’s 39th and final flight, before it is retired along with the rest of NASA’s orbiter fleet in 2011.

The final flight of Discovery already has been delayed by over a month due to technical and weather-related issues. As it stands, the mid-December launch window opens on Dec. 17 and runs through Dec. 20. A Dec. 17 launch, if approved, would occur at 8:51 p.m. EST, NASA officials said.

The shuttle’s planned 11-day mission will deliver a storage room and Robonaut 2, a humanoid robot, to the international space station. Two spacewalks are also planned.

Teams at Kennedy Space Center have been hard at work since Discovery’s launch was originally scrubbed on Nov. 5.

Managers will meet again on Dec. 2 to assess progress toward the Dec. 17 launch opportunity.