At a media conference following the Flight Readiness Review of space shuttle Discovery responds to a question.

At a media conference following the day-long Flight Readiness Review of space shuttle Discovery for the STS-119 mission, NASA's Associate Administrator for Space Operations William H. Gerstenmaier (left) responds to a question. At right are NASA's Space Shuttle Program Manager John Shannon and Program Manager for the International Space Station Mike Suffredini. NASA managers decided to plan a launch no earlier than Feb. 19, pending additional analysis and particle impact testing associated with a flow control valve in the shuttle's main engine system. Photo credit: NASA/Cory Huston