Two hours before Neil Armstrong and Buzz Aldrin were scheduled to leave the surface of the moon after their historic moonwalk, an unmanned Russian probe called Luna 15 crash landed on the lunar surface just 540 miles away from Eagle.

The Luna missions began in 1958, before the Apollo program was even conceived. Its mission was to send a series of robotic spacecraft to the moon—either an orbiter or a lander. The ultimate goal was to bring lunar sample back to earth. Luna 15 was the fifteenth officially designated mission, although in terms of actual launch count it was the thirty-first.