This will be the first launch since Columbia exploded in 2003.
KNIGHT RIDDER NEWSPAPERS
CAPE CANAVERAL, Fla. -- Despite lingering safety concerns, NASA mission managers officially declared Discovery ready for the first shuttle launch since the February 2003 accident that destroyed Columbia and killed its seven astronauts.
Liftoff from the Kennedy Space Center is scheduled for July 13 at 2:51 p.m., though the launch "window" doesn't close until July 31.
"Based on a very thorough and very successful flight readiness review, we are currently go for launch of Discovery," NASA Administrator Michael Griffin said Thursday after a meeting of top shuttle managers that spanned two days.
"The proximate causes of the loss of Columbia have been addressed," he said. "We honestly believe this is the cleanest flight we have ever done. The only flight that will ever be cleaner is the next one."
The decision came despite a report earlier this week from a NASA-appointed task force, which said engineers still had not resolved the three most challenging safety recommendations issued by a post-Columbia investigative panel.
Columbia investigation findings
Columbia shattered in flight as it returned to the space center on Feb. 1, 2003. Investigators blamed the accident on insulating foam that peeled from the shuttle's external fuel tank during blastoff, punched a hole in Columbia's left wing and allowed superheated atmospheric gases to enter the craft.
The task force said that not all sources of foam and other debris had been eliminated; the shuttle has not been sufficiently "hardened" and astronauts still lack a proven technique to repair damage during a mission.
Still, the task force praised NASA for fulfilling 12 other safety recommendations, and several of its leaders said they would not hesitate to fly aboard Discovery. Griffin said Thursday that fixes for the remaining concerns "are not doable based on our knowledge today."