On September 15, 1968, the USSR launched the Zond-5 automatic interplanetary station, which flew around the Moon for the first time in the world and returned to Earth a few days later. The flight of Zonda-5 was carried out as part of the implementation of the Soviet lunar program.

Recall that in the USSR, within the framework of this program, three ships were simultaneously created: "7K-L1" was intended for flying around the Moon, "LOK" - for landing on the Moon, and "7K-OK" was necessary for testing and testing the onboard systems of the first two ships in Earth orbit and solving problems in near-Earth space.

"Zond-5" was an unmanned version of the spacecraft "7K-L1". A total of 15 sets of 7K-L1 spacecraft, upper stages and UR-500K (Proton-K) missiles were created. The schedule for their production was approved on November 13, 1965.

  • A still from the documentary film directed by Nikolai Makarov "Space Tester". Delivery of the Soyuz-3 spacecraft to the launch pad of the Baikonur cosmodrome
  • RIA Novosti
  • © Nikolay Makarov

According to analysts, by the beginning of the implementation of the program for the flyby of the moon, the tests of the UR-500K had not yet been completed, so the country's leadership decided to combine the launches of the 7K-L1 spacecraft with the "run-in" of the UR-500K launch vehicle.

The first copy of the 7K-L1 was used for ground tests as part of a mock-up technological complex. The second in a simplified version was launched towards the Moon on March 10, 1967. All stages of the rocket worked flawlessly. The launch of the third "7K-L1" on April 8, 1967 was unsuccessful - the ship did not reach the moon due to a technical error. The fourth and fifth attempts were also unsuccessful due to the abnormal operation of the upper stages.

More successful was the launch of the sixth "7K-L1", which received the designation "Zond-4". It was launched on March 2, 1968. For seven days, the ship's systems worked properly, however, due to the failure of the orientation system during the return to Earth, the device entered the dense layers of the atmosphere along an uncontrolled trajectory, which is why the self-destruction system was turned on.

The seventh and eighth launches were also emergency.

Finally, the launch of the rocket with the ninth "7K-L1" on September 15, 1968 was marked by success. The spacecraft, named Zond-5, successfully entered a given trajectory and, three days after launch from Baikonur, was the first in the world to fly around the Moon at a distance of 1960 km from its surface.

During the flight, for the first time in history, the Earth was photographed from a distance of 85 thousand km. On September 21, the ship entered the Earth's atmosphere and splashed down in the Indian Ocean, where it was picked up by Soviet sailors. At the same time, the territory of Kazakhstan was considered a regular landing site - Zond-5 deviated from the course due to the untimely shutdown of the autonomous control system and failures in the operation of sensors.

It is worth noting that on board the ship for biological experiments were insects, bacteria, plants and two turtles - they became the first of the terrestrial living beings that flew around the moon and returned safely to Earth.

Americans are pulling ahead;

After the success of the Zonda-5, Soviet designers began further tests. The next step was the launch of the Zond-6 spacecraft. If successful, Soviet designers could proceed to the preparation of a manned mission.

The rocket was launched on November 10. Most of the flight went normally: Zond-6 successfully flew around the moon and took photos. The problems began when we returned to Earth. The device was able to land at the calculated point, but during the descent there was a depressurization. In addition, the braking parachute opened too early and broke away from the descent module. As a result, the ship crashed, but it was still possible to extract photographs of the moon from it.

  • Photo of the eastern edge of the Moon and the planet Earth, taken by the automatic station "Zond-6"
  • © epizodyspace.ru

If there were people on board the Zonda-6, such an accident would lead to the death of the crew, so the manned flight had to be postponed.

Because of this delay, the United States managed to carry out the first flyby of the Moon with a crew on board - on December 21-27, 1968, the American Apollo 8 spacecraft with three crew members on board flew around the Earth's satellite. At the same time, initially the Apollo 8 flight plan provided only for tests in near-earth orbit, but after the success of the Soviet Zonda-5, the Americans were forced to speed up their own lunar program and sent Apollo 8 immediately to the Moon and with the crew.

In the future, the USSR carried out several more launches of the 7K-L1. The 13th copy crashed at the beginning of 1969, so it did not receive the designation "Probe".

The launch of Zonda-7 in August of the same year turned out to be the first completely successful: the device with mannequins on board completed the entire flight program and landed regularly at the calculated point.

By this time, out of 15 7K-L1 ships, three more remained. One of them with astronauts on board in April 1970 was planned to be launched into a flight around the moon. However, these plans were not destined to come true - the landing of Americans on the moon on July 20, 1969 made it meaningless to continue work on the 7K-L1 program. On October 31, 1970, the project was finally closed.

"The Probe launch program was an integral part of the USSR lunar program. After the Soviet Union withdrew from the lunar race, this project was no longer needed and was curtailed, "Ivan Moiseev, head of the Space Policy Institute, scientific director of the Moscow Space Club, explained in a conversation with RT.

In turn, the UR-500K launch vehicle had a more successful fate than the 7K-L1 project.

  • Launch of the Proton-K rocket
  • © www.prlib.ru

Since the beginning of testing in 1967, Proton-K has launched dozens of space payloads into orbit, including vehicles for the exploration of the Moon, Mars, Venus and Halley's Comet. In addition, Proton-K delivered into orbit the world's first long-term orbital station (DOS) Salyut-1 and all subsequent stations of this series, as well as DOS Almaz, all modules for the first orbital station Mir and Russian modules Zarya and Zvezda for the International Space Station.

In addition, Proton-K launched into orbit some of the satellites for the Russian GLONASS navigation system. The last launch of Proton-K was carried out on March 30, 2012. It was replaced by the modernized Proton-M.

"Race for the Moon"

According to Nathan Eismont, a leading researcher at the Space Research Institute, at that time the USSR and the USA were actually going "neck and neck" in the "race for the moon", and the successful launch of Zonda-5 was a "serious step" that brought the flight of Soviet cosmonauts to the moon closer.

"However, in the USSR, mistakes were made in planning, which eventually led to a lag. The fact is that in our country such serious projects were built on internal competition - design bureaus competed for the right to receive an order. It was the usual and, probably, the right approach. But it was necessary to decide who wins in this competition at an earlier stage than it was done in reality. The delay in this matter led to the dispersion of resources, which caused the lag, "said Nathan Eismont in an interview with RT.

Despite the closure of the USSR lunar program, experts consider the launch of Zonda-5 and work within the framework of the 7K-L1 project to be a great achievement of the Soviet design school.

"This project was designed to help ensure the return of astronauts from the moon in the future. In addition, there were animals on the Zonda to assess the radiation situation on the flight path. At that time, the successful launch of Zonda-5 was, without a doubt, an outstanding achievement," concluded Ivan Moiseev.