Stats: Delta 4 history and backlog (updated March 30)

The U.S. Air Force has identified the launch of a next-generation GPS navigation satellite for the first in a series of competitive rocket procurements between United Launch Alliance and SpaceX, service officials announced Wednesday.

United Launch Alliance plans to assemble leftover parts for a Delta 2 rocket display at the Kennedy Space Center Visitor Complex in Florida alongside other icons of U.S. rocketry, the company announced Saturday soon after the final Delta 2 launch.

United Launch Alliance teams ran through an 11-hour countdown Friday at Cape Canaveral to rehearse procedures before the first flight of a modified Atlas 5 rocket with Boeing’s Starliner crew capsule Dec. 20.