Zond program Zond (russian: Зонд, lit=probe) was the name given to two distinct series of Soviet robotic spacecraft launched between 1964 and 1970. The first series, based on the 3MV planetary probe, was intended to gather information about nearby plan ...

(Зонд; Russian for "probe") was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

robotic spacecraft A robotic spacecraft is an uncrewed spacecraft, usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather ...

program launched between 1964 and 1970, using two spacecraft series, one for interplanetary exploration, and the other for lunar exploration.

Program details

The program had two series of spacecraft. The first series, based on the 3MV planetary probe, was intended to gather information about nearby

planets A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a youn ...

. The second series of test spacecraft were intended as a precursor to crewed circumlunar loop flights, using a stripped-down variant of

Soyuz spacecraft Soyuz () is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau (now Energia). The Soyuz succeeded the Voskhod spacecr ...

, consisting of the service and descent modules, but lacking the

orbital module The orbital module is a compartment of some space capsules used only in orbit. It is separated from the crewed reentry capsule before reentry. The orbital module provides 'habitat' space to use in orbit, while the reentry capsule tends to be focu ...

The

Government of the Soviet Union The Government of the Soviet Union ( rus, Прави́тельство СССР, p=prɐˈvʲitʲɪlʲstvə ɛs ɛs ɛs ˈɛr, r=Pravítelstvo SSSR, lang=no), formally the All-Union Government of the Union of Soviet Socialist Republics, commonly ab ...

had suppressed failed

Space Race The Space Race was a 20th-century competition between two Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability. It had its origins in the ballistic missile-based nuclear arms race between the t ...

missions information to prevent bad publicity during the height of the

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because t ...

and the Space Race. Since the

fall of the Soviet Union The dissolution of the Soviet Union, also negatively connoted as rus, Разва́л Сове́тского Сою́за, r=Razvál Sovétskogo Soyúza, ''Ruining of the Soviet Union''. was the process of internal disintegration within the Sov ...

in 1991, much previously restricted information became available.

Zond 1964A

Zond 1964A a SL-6/A-2-e launch vehicle launched 4 June 1964, failed to achieve

Earth orbit Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi) in a counterclockwise direction as viewed from above the Northern Hemisphere. One complete orbit takes days (1 sidereal year), during which time E ...

. The problem was found to be a faulty valve, that failed 104 seconds after launch. The

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

was Molniya-1 No.2, a Soviet communications satellite.

Zond 1967A

Zond 1967A was launched on 28 September 1967. The Soyuz 7K-L1 No.4L s/n 4 craft was 5,200 kg. Sixty seconds after launch the rocket veered off course. The escape tower took the Zond capsule safely away from the falling rocket. The rocket crashed 65 km downrange and ended the attempted Lunar flyby. The SL-12/D-1-e

Proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

launcher first stage had six engines. It has found that a fuel line of one engine was blocked by a rubber plug which had come loose. Had the mission been successful this would have been designated Zond 4.

Zond 1967B

Zond 1967B launched on 22 November 1967 in an attempted Lunar flyby mission. The Soyuz 7K-L1 No.5L craft was 5,200 kg. A second stage failure occurred and the launch vehicle crashed 300 km downrange. The automatic system shutdown the other engines. The Zond capsule separated with the escape tower and was safely recovered. Had the mission been successful this would also have been designated Zond 4.

Zond 1968A

Zond 1968A was launched on 23 April 1968. The Zond was on a Soyuz 7K-L1 s/n 7L. The craft was 5,600kg. The Proton K rocket exploded 4 minutes and 30 seconds after launch. Had the mission been successful this would also have been designated as Zond 5. The second stage rocket failed 260 seconds after launch. Another attempted Lunar flyby. The fault was found to be a short circuit in the control system that caused engine 2 of the SL-12/D-1-e second stage to shut down.

Zond 1968B

Zond 1968B was planned to be launched on 21 July 1968 on a Soyuz 7K-L1 s/n 8L. On 14 July, while preparing for launch, the Blok D (second-stage) rocket exploded. The launchpad explosion killed three workers. The Proton first-stage booster rocket and the Zond spacecraft had only minor damage. Had the mission been successful this would have been designated Zond 7.

Zond 1969A

Zond 1969A was launched on 20 January 1969, a Soyuz 7K-L1 s/n 13, was to be a lunar flyby and return to

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...

with pictures. One engine of the SL-12/D-1-e second stage shut down 25 seconds early. This put the craft into an emergency system shutdown and aborted the flight. The escape tower fired and the Zond craft was returned to Earth safely. Had the mission been successful this would have been designated as Zond 7. The craft was 5,600 kg.

Zond L1S-1

Zond L1S-1 failed on 21 February 1969, this was the first launch of the N-1 rocket, a

super heavy-lift launch vehicle A super heavy-lift launch vehicle can lift to low Earth orbit more than by United States (NASA) classification or by Russian classification. It is the most capable launch vehicle classification by mass to orbit, exceeding that of the heavy-lif ...

built to send a crewed Soviet

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, ...

to the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

, like the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Apollo program. Just 66 seconds after liftoff the engine's turbopumps exploded.

Zond L1S-2

The Zond L1S-2 (Zond-M 2) mission was to be the second test of the N-1 rocket engine, moded SL-15/N-1. Zond L1S-1, the first test N-1 rocket, had failed on 21 February 1969. L1S-2 - Zond-M 2 had a Zond capsule with Moon landing site cameras and a test Soviet Moon lander. L1S-2 goal was to put the lander into lunar orbit. Zond L1S-2 launched on 3 July 1969 at 23:18:32 Moscow time. A few seconds after liftoff, with the rocket at an altitude of about 180 meters, the main engines shut down. The powerful N-1 rocket crashed back on to launchpad and exploded 18 seconds after liftoff. The massive explosion destroyed Pad 110 East (110/38) at the

Baikonur Cosmodrome ''Baiqoñyr ğaryş ailağy'' rus, Космодром Байконур''Kosmodrom Baykonur'' , image = Baikonur Cosmodrome Soyuz launch pad.jpg , caption = The Baikonur Cosmodrome's "Gagarin's Start" Soyuz ...

. The Zond escape tower fired and the capsule landed clear of launchpad, about 1 km away. It was determined that engine 8's oxygen pump had failed and exploded. The explosion damaged the engine, which started an automatic shutdown of all the other engines. Two more subsequent tests of the N1 rocket failed: Soyuz 7K-L1E No.1 and Soyuz 7K-LOK No.1. With these four failures, the N-1 manned lunar program was canceled. NASA used the

Saturn V Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, with multistage rocket, three stages, and powered with liquid-propellant r ...

rocket for lunar missions, a super lift rocket like the N-1.

Cosmos 154

* Cosmos 154 failed to go into the planned translunar trajectory. The craft was 5,600 kg. Cosmos 154 was one of the first Zond attempts.

Zond 3MV-1 No.2

Zond 3MV-1 No.2 launched 19 February 1964, exploded on the pad.

References

{{Inspace Missions to the Moon Zond program Lunar flybys