''Lunokhod 2'' (russian: Луноход-2 ("Moonwalker 2"), also known as Аппарат 8ЕЛ № 204 ("Device 8EL No. 204")) was the second of two

unmanned An uncrewed vehicle or unmanned vehicle is a vehicle without a person on board. Uncrewed vehicles can either be under telerobotic control—remote controlled or remote guided vehicles—or they can be autonomously controlled—autonomous vehicl ...

lunar

rover Rover may refer to: People * Constance Rover (1910–2005), English historian * Jolanda de Rover (born 1963), Dutch swimmer * Rover Thomas (c. 1920–1998), Indigenous Australian artist Places * Rover, Arkansas, US * Rover, Missouri, US ...

s that landed on 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 ...

by the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

as part of the

Lunokhod programme Lunokhod ( rus, Луноход, p=lʊnɐˈxot, "Moonwalker") was a series of Soviet robotic lunar rovers designed to land on the Moon between 1969 and 1977. Lunokhod 1 was the first roving remote-controlled robot to land on an extraterrestrial ...

. The ''

Luna 21 ''Luna 21'' (Ye-8 series) was an unmanned space mission, and its spacecraft, of the Luna program, also called ''Lunik 21'', in 1973. The spacecraft landed on the Moon and deployed the second Soviet lunar rover, ''Lunokhod 2''. The primary obje ...

'' spacecraft landed on the Moon and deployed the second Soviet

lunar rover A lunar rover or Moon rover is a space exploration vehicle designed to move across the surface of the Moon. The Apollo Program's Lunar Roving Vehicle was driven on the Moon by members of three American crews, Apollo 15, 16, and 17. Other rov ...

, ''Lunokhod 2'', in January 1973.Lunokhod 02
NASA Solar System Exploration; page updated March 15, 2018. Retrieved May 31, 2018. The primary objectives of the mission were to collect images of the lunar surface, examine ambient light levels to determine the feasibility of astronomical observations from the Moon, perform laser ranging experiments from

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 surfa ...

, observe solar

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s, measure local

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

s, and study the

soil mechanics Soil mechanics is a branch of soil physics and applied mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a heterogeneous mixture of fluids (usually air and wat ...

of the lunar surface material.

''Lunokhod 2'' rover and subsystems

The rover stood high and had a mass of . It was about long and wide and had eight wheels each with an independent suspension,

electric motor An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...

and brake. The rover had two speeds, about . ''Lunokhod 2'' was equipped with three

television camera A professional video camera (often called a television camera even though its use has spread beyond television) is a high-end device for creating electronic moving images (as opposed to a movie camera, that earlier recorded the images on film). O ...

s, one mounted high on the rover for navigation, which could return high resolution images at different frame rates—3.2, 5.7, 10.9 or 21.1 seconds per frame. These images were used by a five-man team of controllers on Earth who sent driving commands to the rover in real time. Power was supplied by a solar panel on the inside of a round hinged lid which covered the instrument bay, which would charge the batteries when opened. A polonium-210

radioisotope heater unit Radioisotope heater units (RHU) are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators (RTG) and normally provide about one watt of heat each, derived from the decay of a fe ...

was used to keep the rover warm during the long lunar nights. There were four

panoramic camera Panoramic photography is a technique of photography, using specialized equipment or software, that captures images with horizontally elongated fields of view. It is sometimes known as ''wide format photography''. The term has also been applied to ...

s mounted on the rover. Scientific instruments included a

tester, solar X-ray experiment, an astro

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ...

to measure visible and

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

light levels, a magnetometer deployed in front of the rover on the end of a 2.5 m (8 ft 2 in) boom, a radiometer, a

photodetector Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or ...

(Rubin-1) for laser detection experiments, and a French-supplied laser corner reflector. The lander carried a

bas relief Relief is a sculptural method in which the sculpted pieces are bonded to a solid background of the same material. The term ''relief'' is from the Latin verb ''relevo'', to raise. To create a sculpture in relief is to give the impression that the ...

Vladimir Lenin Vladimir Ilyich Ulyanov. ( 1870 – 21 January 1924), better known as Vladimir Lenin,. was a Russian revolutionary, politician, and political theorist. He served as the first and founding head of government of Soviet Russia from 1917 to 19 ...

and the State Emblem of the Soviet Union. The lander and rover together massed 1814 kg.

Mission

The

Proton-K The Proton-K, also designated Proton 8K82K after its GRAU index or SL-12 after its model number, 8K82K, was a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and launched from sites 81 an ...

/ D launcher put the spacecraft into Earth

parking orbit A parking orbit is a temporary orbit used during the launch of a spacecraft. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory. The alternative to a parking orbit is ''di ...

followed by translunar injection. On January 12, 1973 ''Luna 21'' was braked into a lunar orbit. On January 13 and 14, the

perilune An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elli ...

was lowered to altitude.

Landing and surface operations

On January 15, 1973, after 40 orbits, the descent of the craft was commenced as the

braking rocket A retrorocket (short for ''retrograde rocket'') is a rocket engine providing thrust opposing the motion of a vehicle, thereby causing it to decelerate. They have mostly been used in spacecraft, with more limited use in short-runway aircraft land ...

was fired at altitude, and the craft began to de-orbit. At an altitude of the main thrusters began firing, slowing the fall until a height of was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was above the surface, where the engine was switched off. Landing occurred at 23:35 UT in Le Monnier crater at 25.85 degrees N, 30.45 degrees E. After landing, the ''Lunokhod 2'' took TV images of the surrounding area, then rolled down a ramp to the surface at 01:14 UT on January 16 and took pictures of the ''

'' lander and landing site, driving for 30 metres. After a period of charging up its batteries, it took more pictures of the site and the lander, and then set off to explore the moon. The rover would run during the

lunar day A lunar day is the period of time for Earth's Moon to complete one rotation on its axis with respect to the Sun. Due to tidal locking, it is the time the Moon takes to complete one orbit around Earth ( Earth rise to Earth set) plus about 2.2 mo ...

, stopping occasionally to recharge its batteries with the solar panels. At night the rover hibernated until the next sunrise, heated by the radioactive source. * January 18, 1973 to January 24, 1973: The rover drives 1,260 metres * February 8 to 23: The rover drives 9,086 metres further * March 11 to 23: The rover drives 16,533 metres further * April 9 to 22: The rover drives 8,600 metres further * May 8 to June 3: The rover drives 880 metres further Lunokhod-mission

End of mission

On June 4, 1973 it was announced that the program was completed, leading to speculation that the vehicle probably failed in mid-May or could not be revived after the lunar night of May–June. More recently, Alexander Basilevsky related an account in which on May 9, the rover's open lid touched a crater wall and became covered with dust. When the lid was closed, this dust (a very good insulator) was dumped on to the radiators. The following day, May 10, controllers saw the internal temperature of ''Lunokhod 2'' climb as it was unable to cool itself, eventually rendering the rover inoperable. On May 11, signal from the rover was lost.

Results

''Lunokhod 2'' operated for about four months, and the original estimate was that it covered of terrain, including hilly upland areas and rilles, and sent back 86 panoramic images and over 80,000 TV pictures. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time. ''Lunokhod 2'' was thought to have covered based on wheel rotations but Russian scientists at the Moscow State University of Geodesy and Cartography (MIIGAiK) revised that to an estimated distance of about based on Lunar Reconnaissance Orbiter ( LRO) images of the lunar surface. Subsequent discussions with their American counterparts ended with an agreed-upon final distance of ;Sutherland, Scott (July 29, 2014)
It's Official! NASA confirms Mars Opportunity rover has broken the off-world driving record
theweathernetwork.com an international team has confirmed that the methods used to calculate the two rovers' odometry is consistent and comparable from the Moon to Mars. ''Lunokhod 2'' held the record for off-Earth roving distance until July 27, 2014, when NASA's Mars ''Opportunity'' rover exceeded it after having traveled over .

Current status

''Lunokhod 2'' continues to be detected by lunar laser ranging experiments and its position is known to sub-meter accuracy. On March 17, 2010 Phil Stooke at the

University of Western Ontario The University of Western Ontario (UWO), also known as Western University or Western, is a Public university, public research university in London, Ontario, London, Ontario, Canada. The main campus is located on of land, surrounded by resident ...

announced that he had located ''Lunokhod 2'' in

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

Lunar Reconnaissance Orbiter The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. Data collected by LRO have been described as essential for planning NASA's future human and robotic missions t ...

(LRO) images, but later images showed the initial identification was incorrect (the identified point was a mark in the rover tracks near the end of the route, made as ''Lunokhod 2'' turned around), and the LRO LROC team identified the correct location of the rover in March 2012. Excellent ''Lunokhod 2'' images from LROC were published by Mark Robinson on SESE site of ASU.

Present ownership

Ownership of ''Lunokhod 2'' and the ''Luna 21'' lander was sold by the

Lavochkin NPO Lavochkin (russian: НПО Лавочкина, OKB-301, also called Lavochkin Research and Production Association or shortly Lavochkin Association, LA) is a Russian aerospace company. It is a major player in the Russian space program, being th ...

Association for $68,500 in December 1993 at a

Sotheby's Sotheby's () is a British-founded American multinational corporation with headquarters in New York City. It is one of the world's largest brokers of fine and decorative art, jewellery, and collectibles. It has 80 locations in 40 countries, and ...

auction in New York. (The catalog incorrectly lists lot 68A as ''Luna 17''/''Lunokhod 1''). The buyer was computer gaming entrepreneur and space tourist

Richard Garriott Richard Allen Garriott de Cayeux (''né'' Garriott; born July 4, 1961) is an American video game developer, entrepreneur and private astronaut. Although both his parents were American, he maintains dual British and American citizenship by birth. ...

(son of the astronaut

Owen K. Garriott Owen Kay Garriott (November 22, 1930 – April 15, 2019) was an American electrical engineer and NASA astronaut, who spent 60 days aboard the Skylab space station in 1973 during the Skylab 3 mission, and 10 days aboard Spacelab-1 on a Spac ...

), who stated in a 2001 interview with '' Computer Games Magazines Cindy Yans that: :I purchased Lunakod 21 from the Russians. I am now the world's only private owner of an object on a foreign celestial body. Though there are international treaties that say, no government shall lay claim to geography off planet earth, I am not a government. Summarily, I claim the moon in the name of Lord British! Garriott later confirmed that he is the owner of ''Lunokhod 2''.Are We Alone
. (podcast interview with SETI Institute Director Seth Shostak) December 10, 2007

References

External links

Zarya – ''Lunokhod 2'' chronology

including many from ''Lunokhod 2''

* ttp://planetology.ru/panoramas/lunokhod2.php?page=1&language=english ''Lunokhod 2'' panoramic images
''Lunokhod 2'' in space museum – 360 degree panoramic image

''Lunokhod 2''s path in southern Le Monnier crater {{Portal bar, Spaceflight 2 1973 in the Soviet Union Missions to the Moon Lunar rovers 1973 robots Robots of the Soviet Union Eight-wheeled robots Solar-powered robots Attached spacecraft Spacecraft launched in 1973 1973 on the Moon