Onizuka Air Force Station was a United States Air Force installation in Santa Clara County, California, just outside the city limits of Sunnyvale, at the intersection of U.S. Route 101 and State Route 237. Its main building, known locally as the Blue Cube, is large, pale blue, and windowless, with an array of parabolic dish antennas used for communication with remote tracking stations used to control military satellites. Onizuka AFS was operated by the 21st Space Operations Squadron, a geographically separated unit (GSU) of the 50th Space Wing. Onizuka AFS was closed on July 28, 2010, and operations were moved to the new Ellison Onizuka Satellite Operations Facility at Vandenberg Air Force Base.
Built in 1960 on land near Moffett Field purchased from Lockheed, the station was originally known as the Air Force Satellite Test Center. It was later renamed the Air Force Satellite Control Facility, and Sunnyvale Air Force Station. It was also Lockheed "Building 100". In 1986, the base was renamed Onizuka Air Force Base in honor of Lt Col Ellison Onizuka, USAF, one of the astronauts who, on January 28, 1986, died in the Space Shuttle Challenger disaster. On January 26, 1994, Onizuka Air Force Base was renamed Onizuka Air Force Station.
Realignment of Onizuka Air Force Station was recommended and accepted as part of the 1995 round of the Base Realignment and Closure Program. In summary, the 750th Space Group was to be inactivated and its functions relocated to Falcon AFB, CO. Detachment 2 of the Space and Missile Systems Center would relocate to Falcon AFB (now Schriever AFB), CO and Kirtland AFB, NM, while some other undisclosed tenants would remain in the existing facilities for some time. On May 13, 2005, Defense Secretary Donald Rumsfeld recommended closing the Onizuka Air Force Station in Sunnyvale as part of a fifth round of military base closures and re-sizing. The date by which the realignment and closure must be completed is September 15, 2011.
In April 2007, the mission of the National Reconnaissance Office at Onizuka AFS ended after 46 years.