LONDON – Tech Sgts. Adrian Estrada, left, 422nd Air Base Group, RAF Croughton, and Ron Hoop, 48th Equipment Maintenance Squadron, RAF Lakenheath, keep watch outside the USA House July 25, 2012. Servicemembers, civilian employees and family members from military bases across the United Kingdom volunteered at the USA House as well as the Team Processing Center. (U.S. Air Force photo/Senior Airman Jerilyn Quintanilla)