Surveyor 5

Equipped with a chemical element analyzer for conducting analyses of the lunar soil, the Surveyor 5 lander was the first spacecraft to do a soil analysis on the moon, or any other world. At the outset, the mission nearly failed due to a leak in the spacecraft's thruster system, but engineers devised an alternate braking sequence to land the spacecraft safely.

Returning more than 20,000 photographs taken over three days and making one of the most significant finds of the Surveyor missions (that the moon's surface was likely basaltic rather than powdery and therefore conducive to human exploration), Surveyor 5 became one of the most successful missions of the series.