CAPE CANAVERAL, Fla. – An astronaut who crashed his bicycle last 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 1½ 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; 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.
The setbacks haven't hurt morale in the astronaut corps, said the chief astronaut, Peggy Whitson.
"Everyone is pulling together to support the crew members in a difficult time," she told reporters.
Shuttle crew replacements have happened eight times in the past 30 years, but never at such a late date.
The most famous switch in NASA history occurred 72 hours before Apollo 13 in 1970, after command module pilot Thomas "Ken" Mattingly was exposed to the German measles and yanked from the crew. The three men who flew to the moon on that mission almost didn't make it back alive. An oxygen tank ruptured en route, and it took all of the astronauts' effort and the ingenuity of Mission Control to safely return the crew to Earth.
To cut down on preflight injuries, NASA has a whole list of prohibited activities for astronauts assigned to space missions. Among the banned high-risk sports: motorcycle riding, skiing, parachuting and acrobatic flying. Bicycling is not on the list.
NASA has refused to elaborate on Kopra's injuries, citing medical privacy. The accident involved only Kopra's bicycle, officials said, and occurred near his Houston-area home.
Despite his keen disappointment, Kopra has managed to joke about his situation. Whitson said when she visited him at his home, his cat had a hoop around its head to prevent licking wounds. "He said, 'The cat's in the penalty box, and so am I for getting hurt before the flight,' " she said.
Whitson said Kopra expects a full recovery, but will not be ready to rocket into orbit by Feb. 24. If the mission is delayed until April, it's possible he will be able to rejoin the crew, she noted. At the very least, he will help in Mission Control during the flight.
Kopra, 47, a retired Army colonel, spent two months on the space station in 2009.
Discovery originally was supposed to lift off at the beginning of November. The shuttle holds a load of supplies and spare parts for the space station, as well as the first humanoid robot bound for orbit.
Bowen, 46, a Navy captain, has flown twice in space and performed five spacewalks.
"He's got a very even head and calm composure, and that also makes him easy to substitute and put in here without disrupting the crew," Whitson said.
Astronauts typically go through six to eight underwater sessions to train for a spacewalk; Bowen will get two. There's a chance some of the spacewalk chores won't get done, but by choosing someone so experienced, "we're optimizing for success," Whitson said.
Bowen begins training this week with the five other crew members.
The head of NASA's space operations, Bill Gerstenmaier, stressed that the flight will be delayed if additional training is needed.
NASA is retiring its shuttle fleet this year. Only two — possibly three — missions remain.