Three Delta IV Heavy boosters, which were extracted from a United Launch Alliance barge known as the RocketShip, are placed in a Horizontal Integration Facility, May 4, 2020, at Vandenberg Air Force Base, Calif. A HIF is a building within which the stages of a multistage rocket are brought together before the assembled stack is rolled out to the launch pad or space launch complex and raised into a vertical position for final integration and launch. (U.S. Air Force photo by Senior Airman Aubree Owens)