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| Mission type | Lunar science | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Operator | OKB-1 | ||||||||||||||
| COSPAR ID | 1965-056A | ||||||||||||||
| SATCAT no. | 01454 | ||||||||||||||
| Mission duration | 228 days | ||||||||||||||
| Spacecraft properties | |||||||||||||||
| Spacecraft type | 3MV-4 | ||||||||||||||
| Manufacturer | OKB-1 | ||||||||||||||
| Launch mass | 950 kg (2,090 lb) [1] | ||||||||||||||
| Start of mission | |||||||||||||||
| Launch date | July 18, 1965, 14:32 UTC [1] | ||||||||||||||
| Rocket | Molniya SL-6/A-2-e | ||||||||||||||
| Launch site | Baikonur LC-1/5 | ||||||||||||||
| End of mission | |||||||||||||||
| Last contact | March 3, 1966 [2] | ||||||||||||||
| Orbital parameters | |||||||||||||||
| Reference system | Heliocentric | ||||||||||||||
| Eccentricity | 0.2683 | ||||||||||||||
| Perihelion altitude | 0.9 AU (130 million km) | ||||||||||||||
| Aphelion altitude | 1.56 AU (233 million km) | ||||||||||||||
| Inclination | 0.5° | ||||||||||||||
| Period | 500 days | ||||||||||||||
| Epoch | July 19, 1965, 20:00 UTC [3] | ||||||||||||||
| Flyby of Moon | |||||||||||||||
| Closest approach | July 20, 1965 | ||||||||||||||
| Distance | 9,219 km (5,728 mi) | ||||||||||||||
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Zond 3 was a 1965 space probe which performed a flyby of the Moon 's far side, [4] 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. [2] In addition to a 106.4 mm focal length f/8 imaging system for visible light photography and ultraviolet spectrometry at 285-355 nm, it carried ultraviolet (190-275 nm) and infrared (3-4 μm) spectrophotometers, radiation sensors (gas-discharge and scintillation counters), charged particle detector, magnetometer, and micrometeoroid detector. [2] [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 9,219 km (5,728 mi), [2] approximately 35 hours 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 11,570 km (7,190 mi) prior to closest approach and ending at 02:32 UTC and 9,960 km (6,190 mi) past closest approach, covering a period of 68 minutes. [2] [7] The photos covered 19 million km2 (7.3 million sq mi) 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 2.25 million km (1.40 million mi). To test telemetry, the camera film was rewound and retransmitted in mid-August, mid-September, and finally on October 23 at a distance of 31.5 million km (19.6 million mi), thus proving the ability of the communications system. [2] The subsequent transmissions were also at progressively slower data rates but higher quality. [6] The mission was ended after radio contact ceased on March 3, 1966, when it was at a distance of 153.5 million km (95.4 million mi). [2] [5] It operated for 228 days, roughly equivalent to the time needed to survive a journey to Mars and exceeding that needed for Venus. [2]
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 (1:5000000 scale [12] ) and updated complete globe (1:10000000 scale), featuring 95 percent of the lunar surface, [12] were released in the Soviet Union. [13] [14]
| Preceded by Zond 2 | Zond program | Succeeded by None |