CAPE CANAVERAL, Fla. (AP) _ NASA had one last chance to get space shuttle Atlantis off the ground Saturday, or it would have to wait as long as two months to restart building the international space station.
It couldn't afford much more of a delay.
The multibillion-dollar space lab's construction has been on hold since the Columbia disaster 3 1/2 years ago, and NASA and its international partners face a 2010 deadline to finish before NASA stops flying the shuttle fleet. The Atlantis mission, initially planned for 2003, was rescheduled for August, then delayed four times in two weeks.
``It looks like your long wait is over,'' launch director Mike Leinbach told Atlantis commander Brent Jett and his crew as they waited aboard Atlantis Saturday morning.
Minutes later, Atlantis' rockets fired and the shuttle lifted off its seaside pad and streaked into space in what NASA Administrator Michael Griffin called a ``majestic launch.''
As the shuttle headed for orbit, more than 100 cameras zoomed in for any signs of foam breaking off its external fuel tank, the problem that doomed Columbia. Five hours later, shuttle program manager Wayne Hale had little but positive news after reviewing the early reports from officials still poring over the video.
``Not only am I not alarmed, I'm really at ease,'' Hale said. There was some debris, but the first spray came more than four minutes after launch, and it was small pieces with low velocity that appeared to cause no damage, Hale said.
NASA also observed some ice falling after the shuttle reached orbit, again too late in the ascent to worry the space agency.
``The countdown itself went extremely smoothly, which probably shouldn't be surprising considering how many times we tried it,'' Leinbach said.
There was a slight problem when a freon coolant system didn't work properly during ascent, but NASA didn't view it as a major concern. The fuel cells that forced launch delays earlier in the week were working as expected, NASA spokesman Kyle Herring said.
``Great work!'' astronaut Jeff Williams said minutes after the launch from the space station 220 miles above Earth.
Atlantis carried one of the heaviest payloads ever launched into space _ a 17 1/2 ton truss section that will be added to the half-built space station. It includes two solar arrays that will produce electricity for the orbiting outpost. Atlantis' weight was so much that it only had a crew of six, instead of the usual seven astronauts.
Jett and his team face one of the most challenging construction tasks in space history, Hale said.
They will conduct three complicated spacewalks during the 11-day flight to install the $372 million addition, but they should be ready for it _ the crew have trained far longer than any crew, more than four years.
Construction of the space station has been on hold since Columbia disintegrated over Texas on its return to Earth in February 2003, killing seven astronauts. Since then, NASA has struggled to find ways to prevent foam from breaking off the external fuel tank like the chunk that had fatally damaged Columbia's wing during liftoff. NASA engineers are still working on a redesign of the tank.
The crew's Atlantis mission was delayed for three years as NASA worked to figure on the foam problem.
Then in August, with the shuttle ready to go, the astronauts had to wait a little longer: The launch was scrubbed four times in two weeks, first because a lightning bolt hit the launch pad, then Tropical Storm Ernesto threatened _ NASA actually started rolling the shuttle back to its assembly building, but changed course when the forecast improved _ then problems with the electrical system and a fuel gauge cropped up.
In the last delay, Friday morning, the astronauts were already strapped in when NASA scrubbed less than an hour before launch time because a sensor in the hydrogen fuel tank gave an abnormal reading. That delay cost NASA $616,000.
If the shuttle didn't get off the ground this week, NASA would have had to wait until late September or even late October to try again.
Russia plans to send a Soyuz capsule to the space station on Sept. 18, bringing two new crew members to the space station and Anousheh Ansari, a Texas entrepreneur who is to become the first female space tourist. NASA also wanted a daytime launch for Atlantis so it could watch for any damage to the spacecraft.
``We're confident that in the next few weeks, and few years for that matter, NASA is going to prove to our nation and our friends around the world that it was worth the wait,'' Jett said. ``We're ready to get to work.''
The astronauts with him aboard Atlantis are pilot Chris Ferguson and mission specialists Joe Tanner, Dan Burbank, Heidemarie Stefanyshyn-Piper and Steve MacLean of the Canadian Space Agency.