Luna 23
The Soviet Union launches the unmanned space probe Luna 23 toward the moon, intended to gather surface samples from the Mare Imbrium region for return to Earth. The sample collection hardware is unable to complete its task after landing, and ground controllers are only able to receive partial scientific data from the lander, whose batteries run out within three days of landing. It won’t be until 2012, when NASA’s Lunar Reconnaissance Orbiter photographs Luna 23’s landing site from orbit, that the truth will be learned: the lander tipped over on its side during a descent mishap, leaving it intact but unable to gather a soil sample.