Surveyor 1 was launched on May 20th, 1966 and landed in a flat area
inside a 100 km crater north of Flamsteed Crater in southwest Oceanus
Procellarum on June 2nd,
1966. It was the first American probe to soft land on the lunar
surface. Surveyor 1 was primarily an
engineering test mission for Apollo, validating technologies necessary for
flying and landing on the lunar surface. It returned 10,338 photos, including
some of the probe’s footpads and the surrounding terrain, prior to nightfall on
June 14. Surveyor 1 also acquired data on the radar reflectivity of the lunar
surface, bearing strength of the lunar surface, and spacecraft temperatures for
use in the analysis of the lunar surface temperatures. After withstanding a
lunar night, the probe transmitted additional pictures during the section lunar
day before its battery power ran out.
Lunar Orbiter 1
Lunar Orbiter 1 was launched on August 10th, 1966 and entered lunar orbit
92.1 hours later. It took a total of 42 high resolution and 187 medium
resolution photos, covering over 5 million square km of the Moon's surface. It
also took the first two pictures of the Earth ever from the distance of the
Moon. Orbit tracking sensors on Lunar Orbiter 1 showed a slight
"pear-shape" to the Moon based on the gravity field and no
micrometeorite impacts were detected.
Luna 11
Luna 11 was launched on August 24th, 1966 and entered lunar orbit on August 28th, 1966. It
studied lunar gamma- and X-ray emissions in order to determine the Moon's
chemical composition, lunar gravitational anomalies, the concentration of
meteorite streams near the Moon, and the intensity of hard corpuscular
radiation near the Moon.
Luna 12
Luna 12 was launched on October 2nd, 1966 and entered lunar orbit on October 25th, 1966. It
returned an unknown number of pictures of the lunar surface.