An anonymous reader writes "The launch of Space Shuttle Discovery was originally slated for February 12th, has now been postponed to February 19th — at the earliest. The change of launch dates were decided by NASA managers during a review of the shuttle's flow control valve in the main engine. The new date is pending further analysis of the flow control valve and everything checking out okay for pre-flight tests. Discovery's STS-119 14-day mission will deliver the station's fourth and final set of solar arrays, completing the orbiting laboratory's truss, or backbone. The arrays will provide the electricity to fully power science experiments and support the station's expanded crew of six in May."