Ranger Missions

The Beginnings

The earliest US proposals for lunar exploration originated from the Jet Propulsion Laboratory (JPL) of the California Institute of Technology in the period immediately following the launch of Sputnik. In early 1958, the JPL proposals were reviewed by the Advanced Research Project Agency (ARPA) of the US Department of Defense (DOD). In March 1958, ARPA announced a program with the objectives of determining the US capability of exploring space in the vicinity of the moon, to obtain useful data concerning the moon and to provide a close look at the moon. The program, known as Pioneer, was to be a part of the US contribution to the International Geophysical Year and was to consist of three launches by the US Air Force, carrying a lunar probe built by an Air Force contractor, Space Technology Laboratories, and two by the US Army, carrying a lunar probe to be built by JPL. The first three Pioneer launches did not achieve escape velocity and did not reach the vicinity of the...