CAPE CANAVERAL (Florida)(AFP) - The US space shuttle Endeavour Thursday headed for the orbiting International Station on a mission to complete work on the Japanese Kibo laboratory. The six Americans and one Canadian onboard Endeavour are scheduled to reach the ISS on Friday, where they will install a platform for astronauts to conduct experiments 350 kilometers (220 miles) above Earths surface. The shuttle blasted off Wednesday from the Kennedy Space Center, its sixth bid in recent weeks to reach the ISS after delays caused by weather woes and technical troubles. Soaring spectacularly into the Florida sky, the shuttle accelerated into space faster than the speed of sound, reaching 26,000 kilometers (16,150 miles) per hour in less than nine minutes. Eight minutes after launch the shuttle entered orbit 225 kilometers (140 miles) above Earth, and a few moments later the shuttle could be seen successfully separating from the external fuel tank. NASA said it hoped the launch would help fulfill Japans hope for an out-of-this-world space laboratory, as the shuttle delivers state-of-the-art equipment to conduct experiments in the vacuum of space. A US space agency official downplayed the potential of damage caused by debris that peeled off from Endeavours external fuel tank during liftoff and could be seen hitting the shuttle about two minutes into the flight in images broadcast on NASA TV. The debris could be ice or foam that broke off from the external fuel tank, said Bill Gerstenmaier, NASA associate administrator for space operations. We had some foam loss events, Gerstenmaier told reporters. You can clearly see, on the front part of the orbiter, some white indications where the tiles were dinged. We dont consider those an issue for us, those are probably coating losses, he said. But specialists will scrutinize the images, Gerstenmaier said, and later the shuttle exterior will be closely examined by the Endeavour and ISS crews. The issues will be in the back of the vehicle and well take a look at those when we do the roll-pitch maneuver thats planned, he said. NASA has been cautious about conditions for the space shuttles exit and return since the shuttle Columbia blew apart some 20,000 meters (65,500 feet) above the Earth in 2003 as it was returning from a 16-day space mission to land in Florida. A chunk of insulation that broke off from the shuttles external fuel tank during takeoff had gouged Columbias left wing heat shield, allowing superheated gases to melt the shuttles internal structure before it exploded, killing all seven astronauts onboard. Earlier, NASAs relief was evident when it became clear that weather would not cause another costly liftoff delay. Persistence pays off, good luck and God speed, said launch director Pete Nickolenko. Endeavours launch has been scrubbed three times since Saturday due to inclement weather. Two earlier attempts in June were aborted after potentially hazardous leaks to the shuttles external fuel tank were discovered. The aborted attempts left the cash-strapped US space agency footing 4.5 million dollars in extra costs. The shuttle crew includes Canadian Julie Payette, an electrical and information engineer who has been in space before and is the only woman on board. She was the final astronaut to board Endeavour Wednesday, blowing a kiss to NASA TV cameras before stepping through the cockpit hatch. American aerospace engineer Tim Kopra, 46, will replace Japanese astronaut Koichi Wakata, spending several months aboard the orbiting station. He would be the latest addition to the permanent crew of the ISS, which is a joint collaboration between 16 different countries. The ISS should be completed in 2010, also the target date for the retirement of the US fleet of three space shuttles.