Luna 23, launched October 28, 1974, was a Soviet spacecraft that was intended to land on the moon and return to Earth with a sample of lunar soil. Luna 16 and Luna 20 had returned successfully to Earth with samples taken from depths of 0.3 m. Luna 23 was to drill down to 2.5 m, but upon landing, it tipped over onto its side, thus rendering any sampling impossible.
Scientists manged to remain in contact with the probe until November 9.
