Associate Administrator for Space Operations Bill Gerstenmaier, Space Shuttle Program Manager John Shannon and Space Shuttle Launch Director Mike Leinbach respond to media questions about the flight readiness review news conference for space shuttle Discovery's STS-119 mission. NASA managers decided Feb. 20 more data and possible testing are required before proceeding to launch. Engineering teams have been working to identify what caused damage to a flow control valve on shuttle Endeavour during its November 2008 flight. A new launch date has not been determined. Photo credit: NASA/Glenn Benson