The five Lunar Orbiter missions, all successful, were launched at three-month intervals from August 10, 1966, through August 1, 1967. The program was a series of spacecraft used for lunar mapping. General area of interest for Apollo landing sites was a rectangle extending five degrees north and south of the lunar equator and 45 degrees east and west of the lunar prime meridian. As a result of the program, 95 percent of the Moon's surface was photographed.