Weather satellite launch delayed to repair rocket leak

A countdown simulation for the upcoming Delta 4 rocket launch carrying a next-generation weather satellite has uncovered a liquid oxygen leak on the booster's first stage, a problem that will delay liftoff at least a couple of weeks. Officials announced Friday that the launch would slip from April 28 to mid-May as a result. Standing atop pad 37B at Cape Canaveral Air Force Station, the Delta 4 underwent a full launch day rehearsal Wednesday. The mobile service tower was rolled back and the two-stage rocket was filled with supercold liquid hydrogen and liquid oxygen while the launch team practiced the countdown procedures. More

(Source: SpaceFlightNow.com - Apr 11)