Astronaut Mark Kelly listens to a question at a news conference where it was announced that he will serve as commander of the STS-134 space shuttle mission at the Johnson Space Center in Houston February 4, 2011. Kelly has been on leave from NASA caring for his wife, U.S. Congresswoman Gabrielle Giffords, who was critically wounded in a Tucson, Arizona shooting. REUTERS/Richard Carson (UNITED STATES - Tags: SCI TECH SOCIETY)