The space shuttle Discovery will blast off next Tuesday on a mission to the International Space Station, NASA said, clearing the launch after days of debate over safety issues.

Lift-off was set for 5.36am GMT from the Kennedy Space Centre near Cape Canaveral in Florida, NASA said, after two days of meetings between mission officials.

"It was a very effective review. I think we're ready to go fly," Bill Gerstenmaier, NASA's associate administrator for space operations, told a briefing.

Launch director Pete Nickolenko concurred. "I think the largest hurdles are behind us," he said. "The teams are in great shape to make this launch attempt on the 25th."

Safety talks had been "primarily dominated by the external tank foam issue, and really looking very hard at these data," John Shannon, NASA's space shuttle manager, said.

Foam fragments tore off the external tank of the shuttle on the last two launches, and NASA wants to make sure the tank used by Discovery doesn't show the same weakness.

Seven astronauts will travel aboard Discovery, including Nicole Stott, who will remain on the ISS for three months.

She will replace Tim Kopra, who has been on the orbiting station since July. Discovery will be transporting several tonnes of food and supplies as well a freezer to store test results.

NASA has been very cautious about exit and return conditions since the shuttle Columbia blew apart in 2003 as it returned from a 16-day space mission, killing all seven astronauts on board.

A chunk of insulation that broke off from Columbia's external fuel tank during take-off gouged the craft's heat shield, allowing superheated gases to melt the shuttle's internal structure.