The spacecraft, which carried scientific probes including cosmic ray and micrometeoroid detectors, photography equipment, and a biological payload (flies, bacteria and turtles), was a precursor to a manned circumlunar flight which the Soviets hoped could occur in December 1968, beating the American Apollo 8.
Pesawat ruang angkasa, yang membawa probe ilmiah termasuk sinar kosmik dan detektor micrometeoroid, peralatan fotografi, dan muatan biologis, adalah pendahulu untuk penerbangan berawak yang circumlunar Soviet diharapkan bisa terjadi pada Desember 1968, mengalahkan Amerika Apollo 8.