Apollo 12 astronaut visits Surveyor 3, with Apollo 12 in background on the lunar surface. (NASA photo)

The Surveyor series of robotic spacecraft were the first American vehicles to "soft land" on the moon. Surveyor 1 landed June 2, 1966.

Surveyor 1 was not the first, though. Russia's Luna 9 made it there first about four months earlier. Surveyor was recently photographed from a satellite in orbit around the moon. (see lower photo)

All the Surveyors had the same framework, but were loaded with different types of instruments for each mission, investigating the surface for the upcoming Apollo manned missions.

Two of the seven Surveyor craft did not land on the moon because of technical problems.

Apollo 12, the second manned lunar expedition, landed close enough to Surveyor 3 that astronauts Pete Conrad and Alan Bean took some "selfies" with the craft (upper photo).