Queen Elizabeth II greets children on her walk from NASA’s Goddard Space Flight Center mission control to a reception in the center’s main auditorium, Tuesday, May 8, 2007, in Greenbelt, Md. Queen Elizabeth II and her husband, Prince Philip, Duke of Edinburgh, visited the NASA Goddard Space Flight Center as one of the last stops on their six-day United States visit. Photo Credit: (NASA/Bill Ingalls)