In January 2013, the museum opened the US Freedom Pavilion: The Boeing Center, which is the now largest building on the campus. The collection in the US Freedom Pavilion includes a B-17E Flying Fortress bomber, a B-25J Mitchell bomber, an SBD-3 Dauntless, a TBF Avenger, a P-51D Mustang, Corsair F4U-4 and an interactive submarine experience based on the final mission of the USS "Tang". The B-17E is the airplane dubbed "My Gal Sal", famous for having been lost over Greenland and recovered 53 years later. The US Freedom Pavilion was paid for with a $15 million donation from the Boeing Company and with a $20 million grant from the US Department of Defense with congressional approval.