Shuttle cleared for landing after safety checks on nose and wings

Mission Control gave the go-ahead yesterday for the space shuttle Discovery to land today, after inspections of its protective skin showed no signs of damage.

Images of the shuttle's wings and nose cap were taken by the crew over the weekend using sensors at the end of a 100ft boom and robotic arm. Damage to a wing of the shuttle Columbia caused the spacecraft to break up on re-entry to the earth's atmosphere in 2003 killing all seven astronauts.

Nasa said it would consider using the back-up landing site at Edwards Air Force Base in California if controllers were forced to postpone a landing at the Kennedy Space Centre because of bad weather. The shuttle must land by Wednesday.

Discovery will try to land at3.50pm or 4.14pm BST, completing a successful 13-day mission that took supplies and an extra crew member to the international space station and allowed astronauts to repair a rail car on the station.

Mission Control also told Discovery that a leaking unit that powers hydraulic systems used for steering and braking should not pose any difficulties during landing. Engineers were unsure whether it had been leaking harmless nitrogen or flammable hydrazine, but tests showed no problems.