Vandenberg Space Launch Complex 6

Space Launch Complex 6 (SLC-6, pronounced "Slick Six") at Vandenberg Space Force Base in California is a launch pad and support area. The site was originally developed starting in 1966, but no launches occurred until 1995, as it was repurposed sequentially for three programs that were subsequently cancelled. Initially to be used for Titan IIIM rockets and the Manned Orbiting Laboratory, these were cancelled before construction of SLC-6 was complete. The complex was later rebuilt to serve as the west coast launch site for the Space Shuttle, but went unused due to budget, safety and political considerations. The pad was subsequently used for four Athena rocket launches before being modified to support the Delta IV launch vehicle family, which used the pad for ten launches from 2006 until 2022. The last Delta IV launched in September 2022, and SpaceX leased SLC-6 in 2023 to convert it to launch Falcon 9 and Falcon Heavy starting in 2025.

Launches from Vandenberg fly southward, allowing payloads to be placed in high-inclination orbits such as polar or Sun-synchronous orbit, which allow full global coverage on a regular basis and are often used for weather, Earth observation, and reconnaissance satellites. These orbits are difficult to reach from Cape Canaveral Space Force Station, where launches must fly eastward due to major population centers to both the north and south of Kennedy Space Center. Avoiding these would require major inefficient maneuvering, greatly reducing payload capacity.