Pictured is Lt. Col. Merryl Tengesdal, the only black female U-2 pilot in history. "The Air Force has always been on the forefront of breaking aviation and racial barriers," Tengesdal said. "I am extremely proud of being the first black female U-2 pilot in history." Read Tengesdal's full story on Beale Air Force Base's website. (U.S. Air Force graphic/Staff Sgt. Andrew Park; U.S. Air Force Photo/Senior Airman Bobby Cummings)