While the Mercury, Gemini, and Apollo programs developed core technologies, selected and equipped astronauts for deep space exploration, other robotic precursor programs provided the reconnaissance data critical for planning, simulating, and executing Apollo field activities. The earliest, Ranger (1961–1965), implemented by NASA JPL, established the basic capabilities for navigation, tracking, and communication from the Earth to the Moon. Lunar Orbiter (1966–1967), implemented by NASA Langley, confirmed the capability for orbital insertion and provided pictures of the potential landing sites at nominal resolution of 1 meter. Lunar Surveyor (1966–1968), implemented by NASA JPL, verified that soft landing on the moon was possible, established that the regolith could support a lander and its crew, and provided the first pictures and compositional data of the lunar surface in situ. Aerial reconnaissance data with comparable resolution were obtained for selected terrestrial sites where simulation and astronaut training would be performed. From 1968 to 1969, prior to lunar landing, Apollo crewed missions demonstrated crucial capabilities including (1) operation of the command module in Earth orbit (Apollo 7), (2) operation of the command module to, from and around the Moon (Apollo 8), (3) operation of the full Apollo configuration, both command and lunar module, in Earth orbit (Apollo 9), and (4) all operations for lunar landing at the moon except actually landing (Apollo 10).