An OC-135B Open Skies aircraft goes through pre-flight checks Jan. 16, 2010, at Joint Base Andrews, Md. The OC-135 is with the 45th Reconnaissance Squadron at Offutt Air Force Base, Neb., and is used to conduct observation flights in support of the Open Skies Treaty. (U.S. Air Force photo/Airman 1st Class Perry Aston)