Cape Canaveral, FL (CBS/AP) -- Space shuttle Discovery and a crew of seven rocketed away Tuesday in pursuit of the international space station, where a formidable construction job awaits them.
Discovery blasted off at 11:38 a.m., carrying up a giant Tinkertoy-type link that must be installed at the space station before European and Japanese laboratories can arrive.
Despite a forecast calling for rain right at launch time, the weather ended up cooperating. And a chunk of ice on plumbing between the external fuel tank and Discovery - 4 inches by 1½ inches - was deemed too small by NASA to pose a serious launch hazard. It appeared to be melting as the countdown entered its final minutes.
Launch director Mike Leinbach wished the crew good luck and Godspeed just before liftoff.
"We're ready to take Harmony to her new home," replied commander Pamela Melroy, referring to the new space station compartment aboard Discovery.
Discovery and its crew embark on a two-week mission that is considered the most challenging and complex in the nine years of orbital assembly of the international space station.
The shuttle carries an Italian-built live-in compartment, about the size of a small bus, that the astronauts will attach to the space station. It's named Harmony, the choice of schoolchildren who took part in a national competition. About 130 of those youngsters traveled to Cape Canaveral to witness the launch.
Also on hand for the launch was "Star Wars" director and writer George Lucas. Packed aboard Discovery is the lightsaber used by the character Luke Skywalker in 1983's "Return of the Jedi," to mark the 30th anniversary of the first "Star Wars" film.
Europe and Japan's laboratories will link up with Harmony once they are launched by shuttles over the next few months.
Discovery's astronauts also will move a massive girder and set of solar wings from one part of the space station to another. That work will involve extending radiators as well as the folded solar wings - 240 feet from tip to tip when outstretched.
In all, five spacewalks are planned, four to complete this construction job and one to test a method for fixing damaged shuttle thermal tiles using a caulking gun and high-tech goo. The demonstration with sample tiles was added after Endeavour suffered a gouge to its belly during the last launch in August from a piece of flyaway fuel-tank foam.
Once Discovery leaves, the three space station residents - one of whom will be dropped off by the shuttle - will face even more construction work to prepare for the European lab's arrival as early as December.
Discovery's crew includes an Italian astronaut making his first spaceflight, Paolo Nespoli.
The launch is scheduled during a busy time for international space travel.
Sunday, Malaysia's first space traveler and two Russian cosmonauts endured eight times the force of gravity as a technical glitch sent a Soyuz spacecraft on what turned out to be a wild, but safe, ride home.
The Russian space agency says medical tests show all three are fine, despite the steeper-than-usual descent in Kazakhstan, the cause of which is under investigation.
A similar problem occurred in May 2003 when a three-man also experienced a steep, off-course landing. It took salvage crews then several hours to locate the spacecraft because of communications problems.
Also this week, China plans to launch its first lunar probe - only a few days after regional rival Japan put a probe in high orbit over the moon, in a big leap forward for Asia's space race.
The rivalry is likely to be joined soon by India, which plans to send its own lunar probe into space in April.
The launch window for China's Chang'e 1 orbiter has been set for Wednesday through Friday, with the prime time being 6 p.m. (6 a.m. EDT) Wednesday, said Li Guoping, a spokesman for the China National Space Administration.
"The orbiting of the moon is a high-tech project of self-innovation," Li told reporters Monday. "It will set the technological foundation for the development of China's space exploration."
The Chang'e 1 - named after a legendary Chinese goddess who flew to the moon - is to be launched from the Xichang Satellite Launch Center in Sichuan province in southwestern China.
The Chang'e is expected to orbit the Earth while technical adjustments are made, and by Nov. 5, it should enter the moon's orbit.
The goal is to analyze the chemical and mineral composition of the lunar surface, using stereo cameras and X-ray spectrometers to map three-dimensional images of the surface and study the moon's dust.
It will transmit its first photo back to China in the second half of November. "Then it will work for one year of scientific exploration," says Li.
China sent shock waves through the region in 2003, when it became the first Asian country to put its own astronauts into space. This year, China also blasted an old satellite into oblivion with a land-based anti-satellite missile, the first such test ever conducted by any nation, including the United States and Russia.
"The mission has a very strong scientific emphasis," said Sun Kwok, professor of physics and dean of science at the University of Hong Kong. "It's not just about technology. It's more than just launching a satellite, it's more than putting the first satellite in orbit."
"It's very good for China being a major power," said Kwok, who is on an advisory panel of Chinese scientists who have been invited to help with data analysis on the Chang'e's findings. "It shows that China is moving more and more into the international space community."
© MMVII, CBS Interactive Inc. All Rights Reserved.