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.

[1] Congress launched an investigation into "problems of management" at NASA Headquarters and Jet Propulsion Laboratory.

The three missions together demonstrated good performance of the Atlas/Agena B launch vehicle and the adequacy of the spacecraft design, but unfortunately not both on the same attempt.

Ranger 3 had problems with both the launch vehicle and the spacecraft, missed the Moon by about 36,800 km, and has orbited the Sun ever since.

The project team tracked the seismometer capsule to impact just out of sight on the lunar far side, validating the communications and navigation system.

Around the end of Block 2, it was discovered that a type of diode used in previous missions produced problematic gold-plate flaking in the conditions of space.

[11] The first of the new series, Ranger 6, had a flawless flight, except that the television system was disabled by an in-flight accident and could take no pictures.

Ranger 7 photographed its way down to target in a lunar plain, soon named Mare Cognitum, south of the crater Copernicus.

The new images revealed that craters caused by impact were the dominant features of the Moon's surface, even in the seemingly smooth and empty plains.

Its 5,800 images, nested concentrically and taking advantage of very low-level sunlight, provided strong confirmation of the crater-on-crater, gently rolling contours of the lunar surface.