The space shuttle Endeavour has launched, with seven astronauts on board, on its sixth attempt.
The lift-off had been delayed by more than a month due to bad weather and technical difficulties - success came on the eve of the 40th anniversary of the lift-off of man's first Moon landing.
Endeavour will remain docked at the space station for nearly two weeks.
During that time, the shuttle astronauts will help install the third and final piece of the Japanese space station laboratory, a porch for outdoor experiments.
Japan's $1bn laboratory is the largest of the three up there.