Waterside view of Delta 4 GPS 2F-6 Launch

The 100th rocket in America’s Evolved Expendable Launch Vehicle program, the current fleet of boosters used by the nation to get its critical assets into space, was rolled to the pad Friday morning for a vital mission on Saturday.

The first mission for United Launch Alliance’s Vulcan rocket as part of the National Security Space Launch Phase 2 contract will be USSF-106. ULA began stacking the rocket that will support this mission in October 2024.

The 32-story-tall mobile service tower at the Delta 4’s launch pad at Vandenberg Air Force Base in California was retracted away from the rocket Thursday in advance of a planned liftoff with a top secret National Reconnaissance Office payload.