Zond program

Zond (Зонд; meaning "probe") was the name given to two series of Soviet unmanned space missions undertaken from 1964 to 1970 to gather information about nearby planets and to test spacecraft. The second series used a stripped-down variant of the manned Soyuz spacecraft, consisting of the service and descent modules, but lacking the orbital module.

Missions based on the 3MV planetary probe

The first three missions were based on the model 3MV planetary probe, intended to explore Venus and Mars. After two failures, Zond 3 was sent on a test mission, photographing the far side of the Moon (only the second spacecraft to do so) and continuing out to the orbit of Mars in order to test telemetry and spacecraft systems.

Circumlunar missions

The missions 4 through 8 were test flights for manned circumlunar flight.The Soyuz 7K-L1 (also mentioned just as L1) spacecraft was used for the moon-aimed missions, stripped down to make it possible to launch around the moon from the Earth. They were launched on the Proton rocket which was just powerful enough to send the Zond on a free-return trajectory around the moon without going into lunar orbit (the same path that Apollo 13 flew in its emergency abort). It could have carried 1 or 2 cosmonauts.

There were serious reliability problems with both the new Proton rocket and the new Soyuz, but the test flights pressed ahead with some glitches. The unmanned circumlunar Zond 5 flight in September 1968 was part of the reason NASA flew Apollo 8 to the moon in December 1968 instead of the Earth orbital test which had been planned, because the CIA believed the Soviets were planning a human flight next. Had Apollo 8 not flown when it did, it is possible the Russians would have been the first to fly around the moon in late 1968 or early 1969. However, four of these five Zond flights suffered malfunctions that would have injured or killed any crew.

Instrumentation flown on these missions gathered data on micrometeor flux, solar and cosmic rays, magnetic fields, radio emissions, and solar wind. Biological payloads were also flown and many photographs were taken.

Timetable

3MV planetary probe based missions

*Zond 1
** Launched April 2, 1964
** Communications lost May 14, 1964
** Venus flyby July 14, 1964
*Zond 1964A
** Launched June 4, 1964
** Launch failure
** Attempted Lunar flyby to test spacecraft for future Mars missions
*Zond 2
** Launched November 30, 1964
** Communications lost May, 1965
** Mars flyby August 6, 1965
*Zond 3
** Launched July 18, 1965
** Lunar Flyby July 20, 1965

Soyuz 7K-L1 test missions

*Zond 1967A
** Launched September 28, 1967
** Fell off course 60 seconds after launched. Escape tower took Zond capsule safely away. Rocket crashed 65 km downrange.
** Attempted Lunar flyby
*Zond 1967B
** Launched November 22, 1967
** Second stage failure. Zond capsule was safely recovered. Rocket crashed 300 km downrange.
** Attempted Lunar flyby
*Zond 4
** Launched March 2, 1968
** Study of remote regions of circumterrestrial space, development of new on-board systems and units of space stations.
** Returned to Earth March 7, 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 April 23, 1968
** Second stage failed 260 seconds after launch.
** Attempted Lunar flyby
*Zond 5
** Launched September 15, 1968
** Circumlunar September 18, 1968
** Returned to Earth September 21, 1968
*Zond 6
** Launched November 10, 1968
** Circumlunar November 14, 1968
** Returned to Earth November 17, 1968
*Zond 1969A
** Launched January 20, 1969
** Stage two shutdown 25 seconds early. Automatic flight abort. Capsule was safely recovered.
** Attempted Lunar flyby
*Zond L1S-1
** Launched February 21, 1969
** First stage failure. Capsule escape system fired 70 seconds after launch. Capsule was recovered.
** Attempted Lunar orbiter and N1 rocket test
*Zond L1S-2
** Launched July 3, 1969
** First stage failure. Zond capsule was recovered.
** Attempted Lunar orbiter and N1 rocket test
*Zond 7
** Launched August 7, 1969
** Lunar flyby August 11, 1969
** Returned to Earth August 14, 1969
*Zond 8
** Launched October 20, 1970
** Lunar flyby October 24, 1970
** Returned to Earth October 27, 1970
*Zond 9
** Planned but cancelled
*Zond 10
** Planned but cancelled

External links

* [http://www.astronautix.com/craft/soyz7kl1.htm Very detailed information about the Soyuz 7K-L1 used in Zond 4-8]
* [http://www.myspacemuseum.com/zond.htm Detailed 7K-L1 pictures]
* [http://www.svengrahn.pp.se/radioind/Zondradio/Zondrad.htm Radios in Zond spacecraft]
* [http://www.bbc.co.uk/science/space/exploration/missiontimeline/1960s.shtml Space mission timeline]
* [http://www.lpi.usra.edu/expmoon/zond/zond.html Exploring the Moon: the Zond Missions]