Luna 24 was an unmanned space mission of the Soviet Union's Luna programme. The last of the Luna series of spacecraft, the mission of the Luna 24 probe was the third Soviet mission to retrieve lunar soil samples from the Earth's moon (the first two sample return missions were Luna 16 and Luna 20). The spacecraft orbital dry mass was 4,800 kg (10,600 lb). The probe landed in Mare Crisium (Sea of Crises). The mission returned 170.1 grams (6.00 oz) of lunar samples to the Earth on 22 August 1976.