Between 1959 and 1976, the Soviet Union launched 24 robotic spacecraft toward the moon. These were the Luna missions. On February 3, 1966, Luna 9 became the first spacecraft to land successfully on the lunar surface and transmit photographs back to Earth. On March 13, 1966, Luna 10 became the first artificial satellite of the moon. On August 27, 1966, Luna 11 — essentially a backup of the Luna 10 spacecraft — became the second artificial satellite of the moon. The two latter missions included scientific instruments designed to study lunar chemical composition, gravitational anomalies, and radiation.
