The years from 1963 to 1966 were the busiest of the lunar landing project, no less for science planners than for the spacecraft and rocket builders. After the major decisions made in 1962 provided a basis for planning, the Office of Space Sciences called on its academic advisory bodies to define first the broad outlines of a program of lunar and planetary exploration, then more specific plans for the moon, based on the clearer definition of the Apollo project that was emerging during the period.