Launch Complex 21 (LC-21) at Cape Canaveral Air Force Station, Florida is a launch complex that was used for horizontal launches of cruise missiles between 1958 and 1963. It initially consisted of a single launch rail, from which XSM-73 Bull Goose missiles were tested. Between 1959 and 1960, the complex was rebuilt for the MGM-13 Mace, with a second rail added, and a large concrete structure erected around the launch rails, earning the pad the nickname of "the hardsite".