A United Launch Alliance Delta II rocket blasted off with the Air Forces Global Positioning System IIR-21 satellite from Space Launch Complex 17A at 6:35 a.m. EDT August 17, 2009 This was the 48th successful and last in a series of GPS launches on a Delta II rocket ending an era that began in February 1989. During that time, the Delta II/GPS tandem boasted a 98 percent mission success rate.