ULA Vulcan Launch completes its first National Security Space Launch mission, taking the reins from the Delta IV Heavy for Space Force.

This is a tough business. It takes a million things to go right, one thing to go wrong, said Col. Jim Horne, director of the USSF-106 mission, on launch eve. The stakes are unusually high for this mission: it is the first operational flight of United Launch Alliance’s Vulcan rocket for America.