Nasa unveils shuttle launch date

The shuttle has been grounded for two-and-a-half years

Nasa has set 13 July as the launch date for Discovery, the first shuttle to go into space since the Columbia disaster in February 2003.

The announcement follows a two-day review of the Discovery's readiness for lift-off.

An original launch date in May was put back because of ongoing redesign work on the shuttle's fuel tank.

Columbia disintegrated after re-entering the Earth's atmosphere, killing all seven astronauts on board.

Earlier this week, a panel monitoring Nasa said the agency had failed to meet three of 15 recommendations made by the Columbia Accident Investigation Board (Caib) for the safe resumption of shuttle flights.

But Nasa Administrator Michael Griffin said Discovery was fit for launch.

"Based on a very thorough and very successful flight readiness review, we're currently 'go' for launch of Discovery on 13 July," he announced.

Ice risk

An earlier investigation found Columbia broke up as a result of damage sustained when a chunk of fuel-tank insulating foam smashed into its left wing during lift-off two weeks earlier.

The Caib probe concluded astronauts would still be unable to fix such damage once in orbit.

While Nasa's focus was on how to prevent the insulating foam breaking off, concerns also emerged earlier this year about the build-up of ice on the outside of the fuel tank.

The agency's management however decided the risk of ice striking the shuttle's heat shield was low enough to resume flights.

Discovery will carry a seven-strong crew on a mission to take supplies and parts to the International Space Station.