We have liftoff!

Commander Mark Kelly promised "the greatest show on Earth," and space shuttle Discovery delivered with a thundering, fiery arc stretching over Florida's East Coast on Saturday. The launch began a 14-day mission for Kelly and his crew of seven astronauts as they install a new Japanese-built laboratory module on the International Space Station.

As the astronauts got used to their new surroundings in space, NASA officials on Earth basked in the satisfaction of a flawless countdown and liftoff from NASA's Kennedy Space Center in Florida.

"(It was) obviously a huge day," said NASA Administrator Mike Griffin. "A huge day for the space station partnership, for the Japanese Space Agency, for NASA and, really, for the people who hoped to see the space station do what it was designed to do, to be a place in orbit where we can learn to live and work in space."

Neither weather nor technical problems cropped up as the launch team and mission controllers went through their checks on the way to an on-time liftoff at 5:02 p.m. EDT.

"I reveled in the (launch) team's performance," said Mike Leinbach, shuttle launch director. "It's really a pleasure to have my job and just sit back and watch the launch team."

Next up for the STS-124 mission is a two-day chase across space to link up with the International Space Station. It will take the crew several hours of robotic arm maneuvers and spacewalks to connect the Pressurized Module of Japan's Kibo laboratory to the station. The 36-foot-long module is the largest habitable section to be launched to the orbiting research post.