Vandenberg Air Force Base, Space Launch Complex 3, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Significance: Space Launch Complex 3 (SLC-3) is one of the first operational installations in the United States military space program. The complex was constructed in 1959 to launch satellites into polar orbits without passing over inhabited areas. Since its first launch in 1960, SLC-3 has supported 101 launches of Atlas and Thor boosters carrying a variety of satellite payloads. SLC-3 played an important role in the United States' Cold War defense strategy by supporting surveillance and "early warning system" satellite programs throughout the 1960s and early 1970s. The complex consists of two launch pads, SLC-3 East and SLC-3 West. These pads contain two of the only three remaining A-frame service gantries (mobile service towers) characteristic of early Atlas launch pad construction. The pads are equipped with the only retractable umbilical masts at any U.S. space launch complex.
Survey number: HAER CA-133-1
Building/structure dates: 1959 Initial Construction
Building/structure dates: 1965 Subsequent Work
Building/structure dates: 1968 Subsequent Work
Building/structure dates: 1972 Subsequent Work
Building/structure dates: 1973 Subsequent Work
Building/structure dates: 1974 Subsequent Work
Building/structure dates: 1975 Subsequent Work
Building/structure dates: 1976 Subsequent Work
Building/structure dates: 1977 Subsequent Work
Building/structure dates: 1980 Subsequent Work