Shuttle Begins Descent to Earth

The space shuttle Discovery has begun its descent to Earth after rain and thunderstorms over Florida forced another delay to its return and a change in landing venue.

The shuttle is now expected to touch down at 13.12 BST at Edwards Air Force base in California. It had been due to arrive three hours earlier at the Kennedy Space Centre in Florida, but flight controllers ordered the astronauts to continue circling the planet while waiting for better weather.

When the weather failed to improve, Nasa officials decided to land the shuttle on the other side of the US in the desert of California. The landing had already been postponed from yesterday because of the weather.

Nasa will spend about $1m on returning the shuttle from California to Florida, piggybacking on a Boeing 747, where its launches take place.

Discovery will also land at night; the touchdown on runway 22 at Edwards occurs about 53 minutes before dawn local time.

The shuttle had six opportunities to land today: 10.08 BST and 11.43 BST in Florida, followed by 13.12 BST and 14.47 BST at the Edwards Air Force base.

Flight controllers had also been considering landing at the White Sands Missile Range in New Mexico if the weather did not improve. The landing slots there were 11.39 BST and 13.13 BST.

Nasa administrator Michael Griffin said: "We're going to land [today] one way or another, one place or another."

Discovery has enough fuel and supplies to stay in orbit until tomorrow, but Nasa wanted to reserve that option in case a technical problem arose that takes time to resolve.

Discovery is the first shuttle to attempt a landing since the Columbia disintegrated on re-entry to the Earth's atmosphere two and half years ago, killing all seven astronauts on board.