Space shuttle Discovery blasted off a seaside launch pad at the Kennedy Space Center in Florida on Saturday to deliver Japan's huge new research laboratory to the International Space Station.
The start of NASA's 123rd shuttle mission was as smooth as they come, with no technical glitches and no weather issues as the countdown clock ticked down to 5:02 p.m. EDT (10:02 p.m. British time).
That was the moment when Earth's rotation positioned the shuttle for its most direct path to the orbiting space station.
The shuttle's twin booster rockets roared to life, joining the ship's three hydrogen-burning main engines to catapult the 4.5-million-pound (2.04-million-kg) ship into the air. The load was especially hefty with Japan's Kibo lab tipping the scales at more than 16 tonnes.
"While we all tend to live for today, Kibo will give us hope for tomorrow," said shuttle commander Mark Kelly. "Now stand by for the greatest show on Earth."
Kibo, a complex that cost Japan about $2 billion (1 billion pounds) to manufacture, is being installed aboard the space station in three flights. The elaborate complex includes a storage chamber, launched in March, the main lab aboard Discovery and an outdoor porch slated to fly next year.
Kibo's main segment is a 37-foot (11-metre) by 15-foot (4.6-metre) cylinder that took up much of the shuttle's 50-foot (15-metre) cargo bay.
Japan built a large complex to make sure there was plenty of room for its own ambitious science program as well as those of the station's other partner nations. The United States is entitled to half of Kibo's lab space in exchange for building and operating the station and launching the hardware.
NASA administrator Michael Griffin called the construction of a lab capable of supporting humans in space a milestone for Japan.
"With this step, Japan has shown itself to be fully capable of participating at the highest levels in space exploration," he said at a news conference after the launch.
