Zond program

Did You Know?

• Zond 3 became the second spacecraft to photograph the far side of the Moon, after Luna 3.
• Zond 3 continued out to the orbit of Mars to test telemetry and spacecraft systems.
• The first three Zond missions were based on the model 3MV planetary probe, intended to explore Venus and Mars.

Circumlunar missions

The missions Zond 4 through Zond 8 were test flights for the Soviet Moonshot during the Moon race, using the Soyuz 7K-L1 spacecraft. This stripped-down variant was launched on the Proton rocket, which was just powerful enough to send the Zond on a free return trajectory around the Moon without entering lunar orbit. With minor modification, the spacecraft could carry two cosmonauts. Serious reliability problems affected both the Proton rocket and the Soyuz spacecraft, but test flights pressed ahead with glitches. The majority of flights from 1967 to 1970 showed problems during re-entry. All Zond flights were uncrewed; four suffered malfunctions that would have injured or killed any crew. Instrumentation gathered data on micrometeor flux, solar and cosmic rays, magnetic fields, radio emissions, and solar wind, and biological payloads were also flown.

Timetable

Zond 1 launched 2 April 1964; communications lost 14 May 1964; Venus flyby 14 July 1964. Zond 2 launched 30 November 1964; communications lost May 1965; Mars flyby 6 August 1965. Zond 3 launched 18 July 1965; lunar flyby 20 July 1965; communications lost 3 March 1966. Kosmos 146 launched 10 March 1967 as a prototype Soyuz 7K-L1P launched by Proton into a planned highly elliptical Earth orbit. Kosmos 154 launched 8 April 1967 as a prototype Soyuz 7K-L1P that failed to go into a planned translunar trajectory. Zond 1967A launched 28 September 1967; fell off course 60 seconds after launch; escape tower took the Zond capsule safely away; the rocket crashed 65 km downrange; attempted lunar flyby. Zond 1967B launched 22 November 1967; second stage failure; the Zond capsule was safely recovered; the rocket crashed 300 km downrange; attempted lunar flyby. Zond 4 launched 2 March 1968 for study of remote regions of circumterrestrial space and development of new on-board systems; returned to Earth 7 March 1968; self-destruct system automatically blew up the capsule at 10 to 15 km altitude, 180–200 km off the African coast at Guinea. Zond 1968A launched 23 April 1968; second stage failed 260 seconds after launch; attempted lunar flyby. Zond 1968B (Zond 7K-L1 s/n 8L) launched 21 July 1968; Block D stage exploded on the pad, killing three people. Zond 5 launched 15 September 1968; circumlunar 18 September 1968; returned to Earth 21 September 1968; carried a biological payload of two Russian tortoises, wine flies, meal worms, plants, seeds, bacteria, and other living matter; first spacecraft to circle the Moon and return to land on Earth. Zond 6 launched 10 November 1968; circumlunar 14 November 1968; returned to Earth 17 November 1968; second circumlunar flight with lifeforms; carried turtles, flies, bacteria, cosmic ray and micrometeoroid detectors, and photographic equipment. Zond 1969A launched 20 January 1969; stage two shut down 25 seconds early; automatic flight abort; capsule safely recovered; attempted lunar flyby. Zond L1S-1 launched 21 February 1969; first stage failure; capsule escape system fired 70 seconds after launch; capsule recovered; attempted lunar orbiter and N1 rocket test. Zond L1S-2 launched 3 July 1969; first stage failure; Zond capsule recovered; attempted lunar orbiter and N1 rocket test. Zond 7 launched in 1970.