The shuttle carrying six astronauts took off from the Kennedy Space Center in Florida on Saturday.
The mission's primary goal is to install a $372-million solar power module on the $100-billion space station.
The US space agency had intended to launch the space craft on Friday afternoon but postponed liftoff after the technical fault was found on Friday.
Nasa has been trying to launch Atlantis for nearly two weeks but its efforts have been repeatedly thwarted by unfavourable weather and technical glitches.
Space station assembly has been on hold since the loss of shuttle Columbia and its seven-member crew in 2003.