Lunar Orbiter 2 was launched on November 6th, 1966 and entered lunar orbit
92.5 hours later. It returned a total of 609 high resolution and 208 medium
resolution photos were returned, with resolutions down to 1 meter, including a
spectacular oblique picture of Copernicus crater. It acquired new data on lunar
gravity, radiation, and micrometeoroids
Luna 13
Luna 13 was launched on December 21st, 1966 and landed in the region of Oceanus
Procellarum on December 24th,
1966. It transmitted visual panoramas of the nearby lunar landscape
at different sun angles. It also collected data on the mechanical and physical
properties and the cosmic-ray reflectivity of the lunar surface.
Lunar Orbiter 3
Lunar Orbiter 3 was launched on February 5th, 1967 and entered lunar orbit on
February 8th. Lunar Orbiter 3’s mission was to map areas of the
lunar surface to ascertain safe landing sites for the Surveyor and Apollo space
craft. A total of 149 medium resolution and 477 high resolution images were
returned.
Surveyor 3
Surveyor 3 was launched on April 17th, 1967 and touched down on a 14
degree slope inside a subdued 200 meter crater in southeast Oceanus Procellarum
roughly 370 km south of Copernicus crater on April 20th, 1967. Surveyor 3 returned 6326
pictures and operated a surface sampler that dug a number of trenches as deep
as 18 centimeters. New data on the strength, texture, and structure of lunar
material was transmitted by the spacecraft. Images of an eclipse of the Sun by
the Earth and related thermal measurements were also returned.
Lunar Orbiter 4
Lunar Orbiter 4 was launched on May 4th, 1967 and entered an elliptical near
polar high lunar orbit days later. A total of 419 high resolution and 127
medium resolution pictures were acquired covering 99% of the Moon's near side
at resolutions from 58 meters to 134 meters. Radiation data showed increased
dosages due to solar particle events producing low energy protons.