Zond program Zond () 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 planets. The second series of t ...

(Зонд; Russian for "probe") was a

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

robotic spacecraft Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which t ...

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 generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets by the most restrictive definition of the te ...

. The second series of test spacecraft was 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 spacecraf ...

, consisting of the

service Service may refer to: Activities * Administrative service, a required part of the workload of university faculty * Civil service, the body of employees of a government * Community service, volunteer service for the benefit of a community or a ...

and descent modules, but lacking the orbital module. The

Government of the Soviet Union The Government of the Union of Soviet Socialist Republics (USSR) was the executive and administrative organ of the highest organ of state power, highest body of state authority, the Supreme Soviet of the Soviet Union, All-Union Supreme Soviet. It ...

had suppressed failed

Space Race The Space Race (, ) was a 20th-century competition between the 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 t ...

mission information to prevent bad publicity during the height of the

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

and the Space Race. Since the

fall of the Soviet Union The Soviet Union was formally dissolved as a sovereign state and subject of international law on 26 December 1991 by Declaration No. 142-N of the Soviet of Nationalities, Soviet of the Republics of the Supreme Soviet of the Soviet Union. :s: ...

in 1991, much previously restricted information became available.

Zond 1964A

Zond 1964A, a SL-6/A-2-e launch vehicle, launched on 4 June 1964, but failed to achieve Earth orbit. The problem was found to be a faulty valve, that failed 104 seconds after launch. The payload was

Molniya-1 No.2 Molniya-1 No.2, a Molniya-1 satellite, was the first Soviet communications satellite to be launched. However, it failed to achieve orbit due to a malfunction of the rocket which was carrying it. It was intended to operate in a Molniya orbit, ...

, 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 , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

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 Soyuz 7K-L1 No.5L, sometimes identified by NASA as Zond 1967B, was a Soviet spacecraft which was launched in 1967 as part of the Zond programme. It was a Soyuz 7K-L1 spacecraft, the second of nine to be launched. It was intended to perform a c ...

craft was 5,200 kg. A second stage failure occurred and the launch vehicle crashed 300 km downrange. The automatic system shut down 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 Blok D () is an upper stage used on Soviet and later Russian expendable launch systems, including the N1, Proton-K and Zenit. The stage (and its derivatives) has been included in more than 320 launched rockets . By 2002 its modification Bl ...

(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 Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

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 The N1 (from , "Carrier Rocket"; Cyrillic: En (Cyrillic), Н1) was a super heavy-lift launch vehicle intended to deliver payloads beyond low Earth orbit. The N1 was the Soviet Union, Soviet counterpart to the US Saturn V and was intended to en ...

, a

super heavy-lift launch vehicle A super heavy-lift launch vehicle is a rocket that can lift to low Earth orbit a "super heavy payload", which is defined as more than by the United States and as more than by Russia. It is the most capable launch vehicle classification by mass ...

built to send a crewed Soviet

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

to the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

, like the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Apollo program The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which Moon landing, landed the first humans on the Moon in 1969. Apollo followed Project Mercury that put the first Americans in sp ...

. Pyrotechnics and propellant leaks led to electrical interference in the KORD avionics system. At 68.7 seconds into flight these electrical failures caused the KORD system to shut down all 28 remaining engines.

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 onto the launchpad and exploded 18 seconds after liftoff. The massive explosion destroyed Pad 110 East (110/38) at the

Baikonur Cosmodrome The Baikonur Cosmodrome is a spaceport operated by Russia within Kazakhstan. Located in the Kazakh city of Baikonur, it is the largest operational space launch facility in terms of area. All Russian Human spaceflight, crewed spaceflights are l ...

. The Zond escape tower fired and the capsule landed clear of the 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 crewed lunar program was canceled. NASA used the

Saturn V The 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, had multistage rocket, three stages, and was powered by liquid-propel ...

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 on 19 February 1964, exploded on the pad.

References

{{Inspace Missions to the Moon Zond program Lunar flybys