Zond 3 was a 1965 space probe which performed a flyby of the Moon's far side, taking a number of quality photographs for its time. It was a member of the Soviet Zond program while also being part of the Mars 3MV project. It was unrelated to Zond spacecraft designed for manned circumlunar missions (Soyuz 7K-L1). It is believed that Zond 3 was initially designed as a companion spacecraft to Zond 2 to be launched to Mars during the 1964 launch window. The opportunity to launch was missed, and the spacecraft was launched on a Mars-crossing trajectory as a spacecraft test, even though Mars was no longer attainable.