An astronaut has lost his place on Space Shuttle Discovery's final voyage after being injured in a bicycle accident. Timothy Kopra suffered unspecified injuries on Saturday, six weeks before Discovery's planned lift-off. He is on indefinite sick leave.
He will be replaced by Stephen Bowen who will take over Colonel Kopra's spacewalking duties. The launch has been on hold since November because of fuel tank cracks and is now set for 24 February.
This is the second time in a month that Nasa has had to deal with crew problems. Last week, Nasa named a backup commander for the final flight of Endeavour in April. The official commander, Mark Kelly, remains at the bedside of his wife, Congresswoman Gabrielle Giffords, who was seriously wounded in the Tucson shootings.