Discovery reaches its launch pad

The roll-out took 10 hours

The space shuttle Discovery has reached its launch pad after a brief delay when engineers found a crack in the fuel tank's foam insulation.

The US space agency Nasa said after the 10-hour rollout procedure that the flaw posed no reason for concern.

Discovery is due to be sent to the international space station in the coming months.

It will be the first shuttle Nasa has launched since the Colombia tragedy in 2003, in which seven astronauts died.

Columbia's disintegration was blamed on a foam chunk that fell off the tank during lift-off.

'Not major'

Nasa spokeswoman Jessica Rye said images of Discovery's hairline crack had been examined by the tank manufacturers.

The space agency concluded that no repairs were necessary and continued moving Discovery from its assembly building to the launch pad, four miles (6.4km) away.

Following the 2003 Columbia disaster, the tank has been revamped for Discovery's flight.

"It doesn't sound like it's a major issue, but because the foam is a sensitive issue we want to make sure we're in a safe and right configuration," Ms Rye said when the crack first came to light.

Discovery's first launch window runs from 15 May to 3 June - during which time the international space station will be in an appropriate position.

Everybody at the US space agency, including astronauts, understand that there are no risk-free shuttle missions, but nonetheless they firmly believe that the only way to improve its performance is to send it back into orbit.

"We are ready to go. I look at this as a new beginning," Nasa Flight Director LeRoy Cain said. "There is risk in this business, this business is about managing that risk."