The US space agency Nasa has successfully launched the space shuttle Endeavour - at the sixth attempt.
Earlier launches at the Kennedy Space Centre in Florida were called off because of bad weather and fuel leaks.
The crew will spend 11 days on the International Space Station, finishing work on a Japanese research laboratory.
If the shuttle had not taken off by Thursday, it would have had to have waited until the end of the month to make way for a Russian cargo ship.
"The weather is finally co-operating so it is now time to fly," said launch director Pete Nickolenko. "Persistence pays off, good luck and God speed."
"We're ready to go, and we're going to take all of you with us on a great mission," replied mission commander Mark Polansky.
The orbiter is taking a seven-strong crew into space, made up of six Americans and one Canadian - Julie Payette - who will operate the shuttle's robotic arm during the mission.
Their arrival, on Friday, will bring the total crew on the outpost to 13 - a record for the International Space Station (ISS).Story from BBC NEWS: