CAPE CANAVERAL, Fla. – An astronaut who crashed his bicycle over the weekend won't be taking part in space shuttle Discovery's final voyage next month.

Astronaut Timothy Kopra suffered unspecified injuries in the accident Saturday, just 1 1/2 months before Discovery's planned liftoff. He is recuperating and on indefinite sick leave.

In a rare swap-out Wednesday, NASA removed Kopra from the crew and added veteran spaceman Stephen Bowen, who flew last May on the most recent shuttle flight. Bowen will take over Kopra's spacewalking duties during the 11-day flight; Kopra had been designated as the lead spacewalker and was to venture out twice to perform work on the International Space Station.

The shuttle flight has been on hold since November because of fuel tank cracks. Just last week, NASA said it had finally zeroed in on a cause for the potentially dangerous cracking. Shuttle repair work is continuing inside the Vehicle Assembly Building. Discovery's target launch date is Feb. 24.

This is the second time this month that NASA had had to deal with crew issues.

Last week, NASA named a backup commander for the final flight of Endeavour in April. The official commander, Mark Kelly, remains at the hospital bedside of his wife, Rep. Gabrielle Giffords, who was seriously wounded in a shooting in Tucson, Ariz. His identical twin brother, Scott, is flying on the space station right now as its skipper.