Westover Air Reserve Base is an Air Force Reserve Command (AFRC) installation located in the Massachusetts communities of Chicopee and Ludlow, near the city of Springfield, Massachusetts. Established at the outset of World War II, today Westover is the largest Air Force Reserve base in the United States, home to approximately 5,500 military and civilian personnel, and covering 2,500 acres (10 km²). Until 2011, it was a backup landing site for the NASA Space Shuttle and in the past few years has expanded to include a growing civilian access airport sharing Westover's military-maintained runways. The installation was named for Major General Oscar Westover who was commanding officer of the Army Air Corps in the 1930s.