Commander Eileen Collins and her crew are scheduled for a 3:51 p.m. EDT liftoff.
"After a vigorous, healthy discussion our team has come to a decision: we're ready to go," NASA Administrator Michael Griffin said after a two-day Flight Readiness Review meeting at NASA's Kennedy Space Center in Florida.
"The past two and half years have resulted in significant improvements that have greatly reduced the risk of flying the Shuttle. But we should never lose sight of the fact that space flight is risky."
2014: The Year in Music [PHOTOS]