| Auto: | all | ||||||||||||
| Zond 3 | |||||||||||||
| Mission Type: | Lunar science | ||||||||||||
| Operator: | OKB-1 | ||||||||||||
| Cospar Id: | 1965-056A | ||||||||||||
| Satcat: | 01454 | ||||||||||||
| Spacecraft Type: | 3MV-4 | ||||||||||||
| Manufacturer: | OKB-1 | ||||||||||||
| Launch Mass: | 950kg (2,090lb)[1] | ||||||||||||
| Launch Date: | UTC | ||||||||||||
| Launch Rocket: | Molniya SL-6/A-2-e | ||||||||||||
| Launch Site: | Baikonur LC-1/5 | ||||||||||||
| Orbit Reference: | Heliocentric | ||||||||||||
| Orbit Eccentricity: | 0.2683 | ||||||||||||
| Orbit Periapsis: | 0.9AU | ||||||||||||
| Orbit Apoapsis: | 1.56AU | ||||||||||||
| Orbit Inclination: | 0.5° | ||||||||||||
| Orbit Period: | 500 days | ||||||||||||
| Orbit Epoch: | July 19, 1965, 20:00 UTC[2] | ||||||||||||
| Apsis: | helion | ||||||||||||
| Interplanetary: |
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| Instruments List: |
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| Programme: | Zond program | ||||||||||||
| Previous Mission: | Zond 2 | ||||||||||||
| Next Mission: | None | ||||||||||||
Zond 3 was a 1965 space probe which performed a flyby of the Moon far side,[3] taking 28 quality photographs. 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 crewed 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.
The spacecraft was of the 3MV-4 type, similar to Zond 2.[4] In addition to a 106.4 mm focal length imaging system for visible light photography and ultraviolet spectrometry at 285-355 μm, it carried ultraviolet (190-275 μm) and infrared (3-4 μm) spectrophotometers, radiation sensors (gas-discharge and scintillation counters), charged particle detector, magnetometer, and micrometeoroid detector.[5] It also had an experimental ion engine.
Zond 3 was launched from Baikonur Cosmodrome on July 18, 1965, at 14:38 UTC, and was deployed from a Tyazhely Sputnik (65-056B) Earth-orbiting platform towards the Moon and interplanetary space. This was a repeat of a mission that failed in late 1963 intended to test communication at distances equivalent to the distances experienced by Mars and Earth.[6]
Zond 3's lunar flyby occurred on July 20 with a closest approach of 9219km (5,728miles),[4] approximately after launch. 25 visible light photographs and 3 ultraviolet spectra of very good quality were taken of the lunar surface, beginning at 01:24 UTC and 11570km (7,190miles) prior to closest approach and ending at 02:32 UTC and 9960km (6,190miles) past closest approach, covering a period of 68 minutes.[4] [7] The photos covered 19e6km2 of the lunar surface.[8]
Zond 3 proceeded on a trajectory across Mars' orbit, but not at a time when planetary encounter would occur. These images were transmitted by radio frequency on July 29 at a distance of 2.25e6km. To test telemetry, the camera film was rewound and retransmitted in mid-August, mid-September, and finally on October 23 at a distance of 31.5e6km, thus proving the ability of the communications system.[4] The subsequent transmissions were also at progressively slower data rates but higher quality. The mission was ended after radio contact ceased on March 3, 1966, when it was at a distance of 153.5e6km.[4] It operated for 228 days, roughly equivalent to the time needed to survive a journey to Mars and exceeding that needed for Venus.[4]
In 1967, the second part of the Atlas of the Far Side of the Moon was published in Moscow,[9] [10] based on data from Zond 3, with the catalog now including 4,000 newly discovered features of the lunar far side landscape. [11] In the same year, the first Complete Map of the Moon (1: scale) and updated complete globe (1: scale), featuring 95 percent of the lunar surface,[12] were released in the Soviet Union.[13] [14]