Nickname of main building at Onizuka Air Force Base in Sunnyvale, CA, California: a five story windowless building, surrounded by radar antennae, and painted blue.

And for many years, it was Silicon Valley's ground zero: the most likely target in the event of a Soviet nuclear attack.

From the 1970's until the 1990's, there were no signs on or around the building to indicate that it had a name, or that it belonged to any particular company. However, the Cube was surrounded with antenna and radar dishes, and people who worked across the street at Lockheed and NASA could tell you that it was not their building. No one seemed concerned--long before it was known as "Silicon Valley," aerospace was the main industry-- so if the government wanted a secret building in the Valley, they were entitled. If you had high enough security clearance at Lockheed, or knew someone who did, you could have found out that the Blue Cube was known internally as the Sunnyvale Air Force Station, and it kept track of military satellites.

In 1983, unclassified testimony from the Pentagon before Congress noted a flaw in the United States' strategic command: the Air Force admitted its ability to keep track of the government's military and intelligence satellites was "dependent on the single satellite control facility (SCF) located at Sunnyvale, California." Of the half dozen or so command and control communication sites which the military would use to warn of and retalitate in the event of a Soviet nuclear attack, the Blue Cube was the weakest link-- it was above ground. It was unhardened against blasts and unshielded from electromagnetic pulses. And it was just a few miles from the Pacific Ocean.

According to analysis by the Union of Concerned Scientists, the EMP produced by a single sub-launched nuclear missle airburst over the building would effectively blind US satellites (Which could explain the constant stream of P-3 Orion "subchasers" flying overhead, in and out of the Navy's Moffett Field, 2 miles to the north).

In 1983, with the release of the TV movie "The Day After," the San Jose Mercury News followed up with a feature story on the after-effects of a Soviet attack in the Valley. The story featured a map, with concentric circles spreading out from the Blue Cube, so we could see the effects of blast damage, firestorm damage, and radiation from a single airburst over Sunnyvale (Though the 100,000 residents of Sunnyvale couldn't have been pleased, I studied the map with morbid curiosity from my home in San Jose, 6 miles away, and wondered how far I could run before the black rain started).

One day in the 1990's, a sign popped up on Highway 237: "Onizuka Air Force Base, Next Exit." With the Cold War over, the base was no longer a secret. In 1995, the base was realigned (most of its functions were moved to Falcon AFB (now Schriever AFB) in Colorado), but the Air Force is still there today, tracking DOD satellites, although presumably they've updated their computer equipment (When the semiconductor boom hit Silicon Valley, companies vied to replace the Air Force's punch card fed, refrigerator size computers from the 1960s. Rumors had it that inside the Cube, technicians took the numbers crunched from these behemoths, and tracked the satellites with magic markers on sheets of butcher paper). Today, there are no more P-3s flying over Sunnyvale. And the gleaming corporate headquarters of Ariba Technologies next door makes the architecturally plain, faded Blue Cube look even more like an outdated relic of a long gone era.

Update: As part of the Department of Defense's Base Realignment and Closure 2005, Onizuka was slated for closure, with its functions transferred to Vandenburg Air Force Base. The DoD closed the site in 2010, and in 2011, the nearby City of Sunnyvale signed off on redevelopment plans (developed over a two year public process) that include housing for the homeless, educational facilities (for the nearby Foothill-De Anza Community College District, and a new fire station and emergency services training).

Sources:
"Why Onizuka?", Western Disaster Center Web site, <http://www.wdc.ndin.net/whyonizuka.htm> (20 November 2001)
Edward Hasbrouck, "Moffet Park, Sunnyvale, CA: "Star Wars" Ground Zero," in Poli-Sci Digest, Volume 6: Issue 13, 28 May 1986, <http://www.cs.rutgers.edu/~cwm/NetStuff/Poli-Sci/volume6-2.html> (20 November 2001)
John Schneidawind, "New Pentagon Satellite System Having Troubles"San Francisco Chronicle, Friday, August 12, 1988.
City of Sunnyvale, "Onizuka Air Force Station Redevelopment." <http://sunnyvale.ca.gov/Departments/CommunityDevelopment/OnizukaAirForceStationRedevelopment.aspx> (23 April 2012)