Zond 5 was the first mission to travel around the Moon and return safely to Earth.
The Soviet Union launched Zond 5 on 15 September 1968. The uncrewed spacecraft flew around the Moon, passing about 1,950 kilometers above its surface, and returned to Earth on 21 September. Its reentry capsule splashed down in the Indian Ocean.
Zond 5 carried biological specimens including tortoises, insects, plants, and microorganisms, allowing scientists to study the effects of a circumlunar journey. The mission demonstrated crucial navigation, communications, heat-shield, and recovery systems. Zond 6 followed with another lunar flight but experienced landing problems. Apollo 8 later became the first crewed mission to orbit the Moon, in December 1968.