Ranger program

Ranger

Block III Ranger spacecraft
Manufacturer	Jet Propulsion Laboratory
Country of origin	United States
Operator	NASA
Specifications
Bus	Block I, Block II, Block III
Production
Status	Retired
Launched	9
Failed	5
Maiden launch	August 23, 1961
Last launch	March 21, 1965
Related spacecraft
Derivatives	Mariner
Configuration
Block II Ranger spacecraft

The Ranger program was a series of uncrewed space missions by the United States in the 1960s whose objective was to obtain the first close-up images of the surface of the Moon. The Ranger spacecraft were designed to take images of the lunar surface, transmitting those images to Earth until the spacecraft were destroyed upon impact. A series of mishaps, however, led to the failure of the first six flights. At one point, the program was called "shoot and hope".^[1] Congress launched an investigation into "problems of management" at NASA Headquarters and Jet Propulsion Laboratory.^[2] After two reorganizations of the agencies,^{[citation needed]} Ranger 7 successfully returned images in July 1964, followed by two more successful missions.

Ranger was originally designed, beginning in 1959, in three distinct phases, called "blocks". Each block had different mission objectives and progressively more advanced system design. The JPL mission designers planned multiple launches in each block, to maximize the engineering experience and scientific value of the mission and to assure at least one successful flight. Total research, development, launch, and support costs for the Ranger series of spacecraft (Rangers 1 through 9) was approximately $170 million (equivalent to $1.25 billion in 2023).^[3]