Zond (Russian: Зонд, lit. 'probe') was the name given to two distinct series of Soviet robotic spacecraft launched between 1964 and 1970. The first series, based on the 3MV planetary probe, was intended to gather information about nearby planets.
The second series of test spacecraft was intended as a precursor to remote-controlled robotic circumlunar loop flights, using a stripped-down variant of Soyuz spacecraft, consisting of the service and descent modules, but lacking the orbital module.
Two tortoises and other lifeforms aboard Zond 5 were the first terrestrial organisms to travel around the Moon and return to Earth.