Zond 3

Zond 3, a member of the Soviet Zond program, was launched from a Tyazheliy Sputnik (65-056B) earth orbiting platform towards the Moon and interplanetary space. The spacecraft was equipped with an f106 mm camera and TV system that provided automatic inflight film processing. On July 20 lunar flyby occurred approximately 33 hours after launch at a closest approach of 9200 km. 25 pictures of very good quality were taken of the lunar farside from distances of 11,570 to 9960 km over a period of 68 minutes. The photos covered 19,000,000 square km of the lunar surface. Photo transmissions by facsimile were returned to Earth from a distance of 2,200,000 km and were retransmitted from a distance of 31,500,000 km (some signals still being transmitted from the distance of the orbit of Mars), thus proving the ability of the communications system. After the lunar flyby, Zond 3 continued space exploration in a heliocentric orbit.

The spacecraft design was similar to Zond 2, in addition to the imaging equipment it carried a magnetometer, ultraviolet (0.25 - 0.35 micron and 0.19 - 0.27 micron) and infrared (3 - 4 micron) spectrographs, radiation sensors (gas-discharge and scintillation counters), a radiotelescope and a micrometeoroid instrument. It also had an experimental ion engine.

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 trajectory, although Mars was no longer attainable, as a spacecraft test.

• Launch Date/Time: 1965-07-18 at 14:38:00 UTC
• On-orbit dry mass: 960 kg