Onizuka Air Force Station, Military space facility in Sunnyvale, California, US.

Onizuka Air Force Station was a military satellite facility in Sunnyvale equipped with three large parabolic dish antennas for communications and tracking operations. The dishes named Sun East, Sun West, and Sun 3 monitored satellite signals for defense purposes.

In the late 1950s the Air Force bought about 19 acres from Lockheed, including Building 100, and finished the original facilities in 1960 as Sunnyvale Air Force Station. It hosted the Air Force Satellite Test Center, renamed the Air Force Satellite Control Facility in 1979. The 1995 BRAC round and a 2005 recommendation led to closure on 28 July 2010.

The station was renamed in 1986 for Air Force Lieutenant Colonel Ellison S. Onizuka, an astronaut who died in the Space Shuttle Challenger disaster on January 28, 1986. The name ties a satellite control site to a crew member of the ill-fated mission.

The base was not open to the public and closed in 2010, with operations transferred to other facilities. Today visitors can see only the location where the station once stood.

Building 1003, called the Blue Cube, had no windows and was one story tall, though its blue colour and cube shape made it a local landmark. The site's three parabolic antennas were named Sun East, Sun West and Sun 3. After closure the land was split: 9 acres went to the Foothill–De Anza Community College District and 4.4 acres to the Department of Veterans Affairs.