After a three-month delay, Atlantis finally blasted off Friday on NASA's first space shuttle mission of the year, continuing the construction of the International Space Station.

The shuttle lifted off at 7:38 p.m. EDT (2338 GMT) Friday from its seaside launch pad 39A at Kennedy Space Center in Florida. It is the first launch from that launch pad in over four years.

Cheers and shouts can be heard throughout the KSC as Atlantis roars off the launch pad into a clear blue Florida sky, according to NASA TV.

Launch Director Mike Leinbach wished the Atlantis crew members "good luck and Godspeed." Within 10 minutes after liftoff, Atlantis' solid rocket boosters successfully separated and has fallen away from the orbiter, then main engine cut off followed by jettison of the external tank.

Now, Atlantis has reached orbit and Commander Frederick Sturckow has confirmed a good separation, according to NASA's real-time launch blog. By flight day 3, Atlantis will be ready to dock with ISS.

This is the 21st shuttle mission to ISS, with seven astronauts aboard -- all American men. During the 11-day mission, the crew will install a 17.5-ton new truss segment, unfurl new solar arrays and fold up an old one in three planned space walks.

NASA describes the Atlantis mission, coded STS-117, as "just do it -- again". "If you missed either of the last two missions, now would be the time to catch up," said NASA's space shuttle program.

With two successful assembly missions leading the way, those involved with this flight are hoping it will be the best yet.

"We're really fortunate that we have those guys to follow," Atlantis' commander, Frederick Sturckow, said. "Almost everything went great on those missions, and the things that didn't go so well, we're able to learn from."

Along with Sturckow, the crew includes Pilot Lee Archambault and mission specialists Patrick Forrester, Steven Swanson, John Olivas, James Reilly and Clay Anderson, who will remain on the station to begin a long-duration flight.

Expedition 15 Flight Engineer Sunita Williams, who has been aboard the station since December 2006, will return home on Atlantis.

Atlantis was originally scheduled to launch in mid-March, but a freak hail storm damaged the shuttle's massive external fuel tank as the orbiter stood on the launch pad waiting for the launch. NASA was forced to roll it back to the hanger for repairs, which lasted for more than two months.

After a very long and arduous spring with the repair works, the shuttle got back to launch. No technical glitches or unfavorable weather conditions stopped the Friday show, with Atlantis soaring into the open sky in Cape Canaveral on Florida's Atlantic coast.

This is the fifth shuttle mission since the Columbia accident of February 2003, which forced NASA to ground the shuttle fleet for safety upgrades.

The shuttle returned to space in July 2005 with a Discovery mission focused on making space flight safer. A second safety mission in July last year proved successful, paving the way for the resumption of ISS assembly missions.

Atlantis' construction mission will increase the station's power capability and prepare the station for the arrival of the new modules from European and Japanese space agencies.

NASA hopes to fly at least 12 more construction missions to the space station before the space shuttle fleet is grounded in 2010. The space agency also wants to fly a single mission to repair the Hubble Space Telescope, which NASA officials said Thursday would be in September 2008.

(Xinhua News Agency June 9, 2007)