Scouting the Moon for Apollo: Ranger and Surveyor

Ranger 1, launched on 23 August 1961, was a prototype meant to test the functions and parts needed for later lunar and planetary missions. A launch vehicle malfunction left it in low Earth orbit instead of the high orbit planned, so it completed only part of its mission.

Ranger 2, launched on 18 November 1961, was a second flight test of the Ranger spacecraft system, carrying instruments for cosmic rays, magnetic fields, radiation and dust. It reentered the atmosphere and burned up,.

Ranger 3, launched on 26 January 1962, was a NASA mission to study the Moon. A series of malfunctions sent it past the Moon by about 22,000 miles and into a heliocentric orbit.

Ranger 4, launched on 23 April 1962, was designed to send pictures of the lunar surface in its final ten minutes of flight and to rough land a seismometer capsule. It crashed on the far side of the Moon without returning any scientific data.

Ranger 5, launched on 18 October 1962, carried the same plan as Ranger 4, with pictures, a rough landing seismometer capsule and gamma ray data. An unknown malfunction ran it out of power, and it passed within 725 kilometers of the Moon.

Ranger 6, launched on 30 January 1964, was built to transmit high resolution photographs of the lunar terrain in its final minutes of flight, with six television vidicon cameras in two self contained channels for reliability. A failure of the camera system meant that no images were returned.

Ranger 8, launched on 17 February 1965, was the second successful Ranger, following Ranger 7. It transmitted 7,137 lunar surface photographs, which helped select landing sites for later Apollo missions, before crashing into the Moon as planned.

Ranger 9, launched on 21 March 1965, was the final Ranger on this path. Its six cameras, two wide angle and four narrow angle, sent images that were broadcast live on television to millions of viewers across the United States.

Surveyor 2, launched on 20 September 1966, was meant to be the second lander of the Surveyor program. A mid course correction failure made it lose control, and contact was lost on 22 September.

Surveyor 3, launched on 17 April 1967 and built by Hughes Aircraft, was the second Surveyor to land successfully. It was the first of the program to carry a soil sampling scoop, which it used to test the mechanical properties of the lunar surface material.

Surveyor 4, launched on 14 July 1967, crashed after an otherwise flawless mission when telemetry contact was lost about 2.5 minutes before its planned touchdown at Sinus Medii.

Surveyor 5, launched on 8 September 1967, landed on Mare Tranquillitatis and transmitted a total of 19,118 images back to Earth.

Surveyor 6, launched on 7 November 1967, landed on Sinus Medii, the region Surveyor 4 had been aiming for, and transmitted a total of 30,027 images back to Earth. It accomplished all its planned objectives.

Surveyor 7, launched on 7 January 1968, was the seventh and final lander of the program and the fifth to achieve a soft lunar landing. It transmitted a total of 21,091 pictures back to Earth.