The U.S. space shuttle Discovery lifts off from Launch Pad 39B at the Kennedy Space Center in Cape Canaveral, Florida Dec. 9, 2006. (Xinhua Photo)

U.S. space shuttle Discovery successfully lifted off at 8:47 p.m. EST Saturday (0147 GMT on Sunday) at Kennedy Space Center in Florida, flying to the International Space Station (ISS), according to NASA TV.

This was the first night launch in four years, also marking the third and last shuttle flight in 2006.

Outfitted with its external fuel tank and twin booster rockets at the seaside 39B launch pad, Discovery soared into space on the firing command, leaving splendid flames and roaring sound.

Discovery "lifts off successfully," NASA spokesman Bruce Buckingham announced excitedly.

Several minutes before the scheduled launch time, Launch Director Mike Leinbach wished Discovery crew "good luck and Godspeed."

"We're looking forward to lighting up the night sky and rewiring the ISS," replied commander Mark Polansky.

The launch moment, which was lighting up the Central Florida sky, was just like an amazing painting of masterpiece with the night sky as a cosmic canvas.

So far everything was going well, reported the launch team.

Commander Polansky confirms a good separation of the main engine from the orbiter. Discovery will roll into a heads-up orientation shortly.

Discovery had been scheduled to launch on Thursday night, but thick low clouds over the launch site forced NASA to scrub the first launch attempt just minutes before the planned blastoff. As the weather gradually shaping up, Discovery finally left for the International Space Station on Saturday night.

The shuttle, with five-man, two-woman astronauts aboard, will take another section of the half-built International Space Station's metal truss, or frame, into orbit. The mission will also deliver a new resident crew member, replacing one of the space station's three crew members.

During the planned 12-day mission, shuttle crew, joined by station crew, are expected to install the new truss segment and rewire the station so it can make use of solar arrays installed by the last shuttle crew in September. NASA said the reconfiguration of power system in the planned three spacewalks would be its most complex and critical mission to date.

It will be the second space station assembly flight since NASA resumed flying the shuttles after the 2003 Columbia disaster. NASA needs 14 more flights for completing the construction of the orbital outpost.

All of the three launches after the Columbia tragedy were scheduled during daytime so that cameras on the ground and on the shuttle could take images of the spacecraft's exterior tank in case pieces of thermal insulation or ice might break off during liftoff.

In 2003, foaming breaking off the tank and striking Columbia's wing at liftoff led to the breakup of the space shuttle that killed all the seven astronauts onboard.

NASA lifted the nighttime launch ban so it would have enough time to finish the station before the shuttle fleet's retirement slated for 2010.

NASA had hoped to get this mission finished before New Year's Eve as computers on the shuttle were not designed to make the change from the 365th day of the old year to the first day of the new year while in flight.

NASA had developed a fix but still prefer not to try it.

Commanded by astronaut Mark Polansky, Discovery's crew team in the 117th flight in shuttle program history is among the most culturally diversified of any previous space shuttle crew. There are two African-Americans, an Indian descent, the first Swede in space, a British-born American mission specialist, an Alaskan and a New Jersey Boy.

However, the crew team is also the greenest in eight years when it comes to space flight experience as five of them had never flown in a space shuttle before.

But commander Polansky said each of them had been trained as an astronaut anywhere from eight to 12 years. "I don't consider them rookies," he said.

Discovery is scheduled to return to Earth on Dec. 21.

Editor: Yan