Moonwalker: The Soviet Lunokhod Program
- Aeryn Avilla
- Jun 9, 2021
- 9 min read
Updated: Oct 27
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Lunokhod was a series of Soviet robotic rovers that landed and explored the moon in the early 1970s. The name is Russian for "moonwalker" and the program operated concurrently with the Zond and Luna programs.
The Zond series consisted of six uncrewed missions that flew past or circled the moon and returned to Earth between July 1965 and October 1970. Zond 5, the first successful Soviet circumlunar flight, carried the first living creatures to the moon, most notably a pair of steppe tortoises. The manned Zond spacecraft would have sling-shotted two cosmonauts around the moon but not place them into lunar orbit. Luna was a long-running program that consisted of lunar robotic spacecraft missions— flybys, orbiters, and soft-landings— and despite the Soviets never sending a human to the moon, they did make the first flyby, the first soft landing, take the first photographs of the moon's far side (thanks to captured American film), and deploy the first lunar rover.
The manned Soviet lunar plans are...a lot to get into, but here's what's important to the Lunokhod program. The rovers were initially designed to support the manned lunar landings of the N1-L3 program. The N1 rocket was the Soviet equivalent of the American Saturn V moon rocket— a super heavy-lift launch vehicle intended to carry the L3 expeditionary complex. The L3 system included the Blok G and Blok D upper stages (the fourth and fifth stages of the N1), the Lunniy Korabl (LK) lunar lander, and the Lunniy Orbitalny Korabl (LOK) lunar orbital spacecraft, a modified Soyuz 7K-OK spacecraft. The LOK would have carried a crew of two cosmonauts while the LK would have landed only one. In original plans, two Lunokhod rovers would be sent to the moon to survey the landing site onboard on unmanned LK lander a few weeks before the cosmonaut would arrive in his own. The first LK would serve as a rescue craft should the manned LK fail, as they would be within walking distance of each other.
The Lunokhod rovers were designed under the direction of Georgy Babakin, the Chief Designer at the Lavochkin Design Bureau, and the metal chassis were designed by Aleksandr Kemurdzhian. The rovers were 4.5 feet (1.35 m) high, 5'7" (1.7 m) long, and 4'11" (1.6 m) wide. The tub-like compartment sat on eight independently powered wheels that had only two operating speeds– approximately 1 and 2 kilometers an hour, or 0.6 and 1.2 miles an hour.
On the inside of the tub's lid, which covered the instrument bay, was a solar array that charged the rovers' batteries as they drive across the lunar surface during the day. At night, the lid closed and they went into hibernation mode, the polonium-210 radioisotope heater unit keeping them warm. The rovers were equipped with a cone shaped antenna, a helical antenna, four TV cameras, and special devices to take samples of lunar regolith as well as an X-ray spectrometer, an X-ray telescope, a cosmic ray detector, and a laser device.
The Lunokhod's were transported to the surface by Luna spacecraft and were launched by the Proton-K Blok-D launch vehicle, a four-stage launch vehicle originally designed to launch manned circumlunar spacecraft. It actually launched unmanned lunar and Martian spacecraft, which had varying degrees of success.
The Lunokhod rovers were controlled from NIP-10, a satellite tracking and communications center, located in the formerly closed two Simferopol-28 in Crimea, now the village of Shkolnoye [1]. The center controlled the deep space missions of the Luna, Venera, and Mars programs. A lunodrom, or moondrome, was built to evaluate the performance of and solve issues with the Lunokhod rovers' framework and train engineers to drive them. The lunodrom had an area of 394 feet (120 m) by 230 feet (70 m) and included 54 craters and around 160 rocks of various sizes.
Lunokhod was controlled by two five-man crews of engineers from the Soviet missile defense corps. One man drove the rover using a joystick, one served as navigator, one operated the radio antenna, the flight engineer monitored its systems, and the fifth acted as commander, overseeing Lunokhod's operations. The teams alternated controlling the little rovers every two hours. Lunokhod drove in reverse and made turns the same way tanks do, by slowing one side of its wheels relative to the other. Since the rover's cameras sent single frames to Earth every seven to twenty seconds, not a continuous stream, and because radio signals took three seconds to make the trip from Earth to the moon and back, driving Lunokhod was tedious. In place of a continuous stream was a sort of slideshow with each picture visible for up to twenty seconds, during which Lunokhod could blindly travel up to 26 feet (8 m).
The first Lunokhod rover launched on February 19, 1969, but was lost when its Proton rocket exploded 40 seconds after launch. Like other vehicle failures of the era, this loss was not made public until years later, and resulted in polonium 210, the Lunokhod's radioactive head source, being spread over a large area of Russia.
Lunokhod 1, the first successful Lunokhod rover, launched on November 10, 1970 and was the first roving remote-controlled robotic vehicle to land on another celestial body. Luna 17 carried and landed the rover on the moon. The pair entered lunar orbit on November 15 and soft-landed in Mare Imbrium, or the Sea of Rains, on the 17th. Luna had dual ramps so the rover could easily roll down to the surface. Lunokhod 1 operated for 322 days and traveled 6.5 miles (10.5 km), taking more than 20,000 television images and 206 high-resolution panoramas, and performing 25 lunar regolith analyses. The rover ceased operations on October 4, 1971, the 14th anniversary of the launch of Sputnik. Its final resting place on the surface was a mystery for nearly thirty years until 2010 when Russian scientists found Lunokhod 1 and Luna 17 in an image taken by the NASA Lunar Reconnaissance Orbiter.
Luna 17 taken by Lunokhod 1 | Lunokhod 1's tracks (this webpage)
Lunokhod 2 launched with Luna 21 on January 8, 1973 and entered lunar orbit on January 12 before touching down in the Le Monnier crater at the Sea of Serenity's, or Mare Serenitatis, eastern edge on the 15th. Lunokhod 2 was more advanced than its predecessor and some of its primary objectives included surface photography, studying light levels to determine the practicality of astronomical observations from the moon, and studying the mechanical properties of lunar regolith. Lunokhod 2 took pictures of Luna 21 and their landing site. On May 9, Lunokhod 2 was accidentally driven into a crater and while its controllers were trying to maneuver it out, its open lid touched the crater wall. Regolith fell on top of its solar cells. Lunokhod reemerged an hour later and continued on its journey, but when lunar night came and it closed its lid, it dumped regolith onto its radiator. The rover was no longer able to cool itself and its internal temperature exceeded 150° F (65.5° C). Two days later on May 11, 1973, contact with Lunokhod 2 was lost.
The rover operated for just over four months and covered 24 miles (39 km), including hills and rilles, or the long narrow depressions on the lunar surface that look like channels. Lunokhod 2 took more than 80,000 pictures and 86 panoramas, and program completion was announced on June 4, 1973. The rover held the record for longest distance of surface traveled by a vehicle on an extraterrestrial body until 201 when it was broken by NASA's Mars rover Opportunity.
By the time contact was lost with Lunokhod 2, the Soviet Union had already soft-landed its Mars 3 spacecraft on mars, though it failed 110 seconds after touchdown, and NASA was developing its Viking Mars lander. The final N1 rocket was launched and lost in November 1972 and the last manned Apollo mission, Apollo 17, left the lunar surface in December 1972. Lunokhod 3 was planned for 1977 with Luna 25 but did not launch due to lack of funding and available launch vehicles. It is now on display at the NPO Lavochkin museum in Moscow.
After the collapse of the Soviet Union at the end of 1991, the NIP-10 station was transferred to the Ukrainian Space Agency and the military units that operated there were disbanded in 1998. Over the next few decades, a number of buildings, including the NIP-10's museum, were destroyed, but the large TNA-400 antenna still stands silently pointing to the cosmos.
Drawing and model of Lunokhod 1 and Luna 17 (NASA | via Minsk News)
Two more Lunokhod rovers were built in the 1980s, not for any sort of space exploration, but to help clean up radioactive debris from the Chernobyl nuclear power plant disaster in April 1986. Some of the remote controlled bulldozers the cleanup team initially used were too heavy to operate on the partially-collapses reactor building roof. Lunokhod designers were brought out of retirement after more than a decade since the rovers traversed the moon and two weeks later, two new rovers called STR-1 were complete. The rovers were a natural choice for nuclear disaster recovery work because they already used nuclear decay as a heat source. They were delivered to Chernobyl on July 15, 1986 and cleaned up about 10% of radioactive debris before succumbing to extremely high radiation levels.
More than fifty years later, Lunokhod 1 and Lunokhod 2 remain dormant on the lunar surface. Under Article VIII of the Outer Space Treaty, the framework for all international space law and policy, "a State Party to the Treaty on whose registry an object launched into outer space is carried shall retain jurisdiction and control over such object...while in outer space or on a celestial body." This means Russia, and by extension NPO Lavochkin as the manufacturer of the rovers, retains control over the Lunokhod spacecraft and their Luna landers. In December 1993 at a Sotheby's auction in New York, the Lavochkin Association sold ownership of Lunokhod 2 and Luna 21 to Richard Garriott, a (future) private astronaut and the son of Skylab and Space Shuttle astronaut Owen Garriott, for $68,500, or just under $153,000 when adjusted for inflation. Richard Garriott amassed his fortune developing video games but due to vision problems, could not follow in his father's footsteps as a NASA astronaut. In October 2008, he spent 12 days on the International Space Station as a member of Soyuz TMA-13 and a client of space tourism company Space Adventures [2]. He remains to this day the only private citizen to own an object on a celestial body.
After Lunokhod 2, the next remote-controlled rover to roam the lunar surface was Yutu, a Chinese rover part of the Chang'e 3 mission, which landed in December 2013 and operated until August 2016. The Chinese Chang'e 4 Yutu 2 rover, the Indian Pragyan rover, the Japanese Smart Lander for Investigating Moon Lunar Excursion Vehicles, and the Chinese Chang'e 6 Jinchan rovers landed on the moon in the past ten years. The only American lunar rovers were the Apollo Lunar Roving Vehicles driven on the moon by astronauts. Following Lunokhod 2, the next remotely operated rover to land on a celestial body was a little Mars rover named Sojourner as part of the 1997 Mars Pathfinder mission.
Author's note: Thank you for reading and please remember to like, share, and check out my other posts!
[1] Closed towns or cities are areas with restrictions on residency or travel. They were more common in the Soviet Union during the Cold war and were often near sensitive military and scientific facilities, such as space and nuclear research sites, and near borders. In the US, towns that housed Manhattan Project personnel were kept secret.
[2] Garriott became the first second-generation American space traveler. One of his crewmates, Sergei Volkov, was also the first second-generation Russian cosmonaut (his father is Soviet cosmonaut Aleksandr Volkov).
Bibliography
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Garriott de Cayeux, Richard. “NASA Said No to My Astronaut Dream, So I Found Another Way.” NBC, July 2017. https://www.nbcnews.com/mach/science/nasa-said-no-my-astronaut-dream-so-i-found-another-ncna776056
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This post was written entirely without the use of AI (sorry HAL).
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