Zond 1


Zond 1
Zond 2.jpg
The Russian Zond 1
NamesZond 3MV-1 No. 4
Mission typeVenus lander
COSPAR ID1964-016D
SATCAT no.00785
Spacecraft properties
Launch mass890 kg (1,960 lb)
Dry mass290 kilograms (640 lb)
Dimensions3.6 m (12 ft) tall
1.1 m (3 ft 7 in) diameter
Start of mission
Launch date02:42:40, April 2, 1964 (UTC) (1964-04-02T02:42:40Z)
RocketMolniya 8K78M
Launch siteBaikonur LC-1/5
End of mission
Last contactMay 24, 1964 (1964-05-24)
Orbital parameters
Reference systemHeliocentric
Perihelion altitude0.652 AU
Aphelion altitude1.001 AU
Period274 days
Flyby of Venus
Closest approachJuly 19, 1964
Distance100,000 km (62,000 mi)
← program started
Zond 2 →

Zond 1 was a spacecraft of the Soviet Zond program. It was the second Soviet research spacecraft to reach Venus, although communications had failed by that time. It carried a 90 cm spherical landing capsule, containing experiments for chemical analysis of the atmosphere, gamma-ray measurements of surface rocks, a photometer, temperature and pressure gauges, and a motion/rocking sensor in case it landed in water.


At least three previous Soviet planetary probes had been lost due to malfunctions of the ullage rockets (BOZ) on the Blok L stage, but an investigation found that the problem was easily resolved. The spacecraft, a Venera 3MV-1, was launched on April 2, 1964 from Tyuratam and this time the launch vehicle performed flawlessly. During the cruise phase, a slow leak from a cracked sensor window caused the electronics compartment to lose air pressure. This was a serious problem as Soviet electronics relied on vacuum tubes which would overheat without cooling air. An ill-timed command from ground control turned on its radio system while there was still a rarefied atmosphere inside, causing the electronics to short out by corona discharge. Chief Designer Sergei Korolev was upset at the failure of the mission and demanded higher quality control from the OKB-1 Bureau, including X-rays to test for pressure leaks.

By mid-April, the electronics in the main spacecraft had completely failed and all signal transmission ceased, but communication via the lander could still be performed, and space radiation and atomic-hydrogen spectrometer measurements were received. The star trackers in the spacecraft were also used to align it for a course-correction burn, but the second one was off by 65 feet per second (20 meters per second). Also one of the star trackers failed, forcing ground controllers to place Zond 1 into a spin-stabilization mode. However, all communications had failed by May 14. It passed 100,000 km from Venus on July 14, 1964.

A similar design of landing capsule was used in Venera 3.[1]


Zond missions were presented as engineering tests by the Soviet Union and to an extent at least that may have been the case.[2] Western observers at the time suggested that the name was used as a cover for failed missions in the same manner that Kosmos designations were used for missions that failed to leave Earth orbit.[2] More recently it has been suggested that "Zond" was genuinely the internal program designation for engineering tests but Zond 1 would have been upgraded to Venera had it been more successful.[2] Zond 1 was actually the second craft that was meant to carry the Zond name, but its predecessor failed to leave Earth orbit and was designated Kosmos 21.[2]

See also


  1. ^ Huntress Jr, Wesley T.; Marov, Mikhail Ya (2011). Soviet Robots in the Solar System Mission Technologies and Discoveries. Springer-Praxis. p. 139. ISBN 9781441978974.
  2. ^ a b c d Harvey, Brian (2007). Russian Planetary Exploration History, Development, Legacy and Prospects. Springer-Praxis. pp. 69–72. ISBN 9780387463438.

External links

  • Astrolink description of spacecraft and payload
  • NSSDC spacecraft info
Preceded by
Zond program (interplanetary) Succeeded by
Zond 2