Discovery Launches on Space Station Construction Mission

The shuttle is headed toward a rendezvous with the International Space Station, where astronauts will deliver a school-bus-sized module named Harmony that will provide more living quarters in the station and link it to a planned laboratory space. They also plan to move a 17.5-ton solar panel array to boost the station's power supply, and test a high-tech caulking gun that could be used to repair minor damage in space.

Completing all of these tasks will require five spacewalks during the 10-day mission -- the most ever during a shuttle mission to the space station.

"We hit the jackpot, I won't kid ya. I think this is every astronaut's dream of a mission," mission commander Pamela Melroy told the Web site Space.com. "It's going to be an enormous challenge."

Melroy is the second woman to head a shuttle mission -- the first was former astronaut Eileen Collins, who led missions in 1999 and 2005. Coincidentally, the International Space Station is also being led by its first female commander, U.S. astronaut Peggy Whitson.

In the hours before takeoff, NASA officials discovered a chunk of ice on the pipes that carry super-cold hydrogen from a fuel tank to the shuttle. However, they decided that the small ice patch didn't pose a danger to the flight, and it appeared to be melting before takeoff.

Watching the successful launch was "Star Wars" film director George Lucas. The shuttle is carrying the "lightsaber" used by character Luke Skywalker in "Return of the Jedi," to mark the 30th anniversary of the first "Star Wars" movie.