''Lunokhod 1'' ( Russian: Луноход-1 ("Moonwalker 1"), also known as Аппарат 8ЕЛ № 203 ("Device 8EL No. 203")) was the first of two robotic

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 ...

s 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 nationa ...

as part of its Lunokhod program. The '' Luna 17''

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, ...

carried ''Lunokhod 1'' to the Moon in 1970. ''Lunokhod 1'' was the first remote-controlled robot "rover" to freely move across the surface of an

astronomical object An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''body'' are often u ...

beyond the Earth. It was also the first wheeled craft on another celestial body. Lunokhod 0 (No.201), the previous and first attempt to do so, launched in February 1969 but failed to reach orbit. Although only designed for a lifetime of three lunar days (approximately three Earth months), ''Lunokhod 1'' operated on the lunar surface for eleven lunar days (321 Earth days) and traversed a total distance of 10.54 km.

Rover description

''Lunokhod 1'' was a lunar vehicle formed of a tub-like compartment with a large convex lid on eight independently powered wheels. Its length was . ''Lunokhod 1'' was equipped with a cone-shaped

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

, a highly directional helical antenna, four

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). ...

s, and special extendable devices to test the lunar soil for soil density and mechanical properties. An X-ray spectrometer, an

X-ray telescope An X-ray telescope (XRT) is a telescope that is designed to observe remote objects in the X-ray spectrum. In order to get above the Earth's atmosphere, which is opaque to X-rays, X-ray telescopes must be mounted on high altitude rockets, balloon ...

cosmic ray Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

detectors, and a

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The ...

device were also included. The vehicle was powered by batteries which were recharged 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 ...

by a

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

array mounted on the underside of the lid. To be able to work in a vacuum, special fluoride-based lubricant was used for the mechanical parts, and the electric motors (one in each wheel hub) were enclosed in pressurized containers. During the lunar nights, the lid was closed, and a

polonium-210 Polonium-210 (210Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206Pb with a half-life of 138.376 days (about months), the longest half-life of all naturally occurring polonium isotopes. First ...

radioisotope heater unit kept the internal components at

operating temperature An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the de ...

. ''Lunokhod 1'' was intended to operate through three lunar days (approximately three Earth months), but actually operated for eleven lunar days.

Launch and lunar orbit

'' Luna 17'' was launched on November 10, 1970 at 14:44:01 UTC. After reaching earth parking orbit, the final stage of ''Luna 17''s launching rocket fired to place it into a trajectory towards the Moon (1970-11-10 at 14:54 UTC). After two course correction maneuvers (on November 12 and 14), it entered

lunar orbit In astronomy, lunar orbit (also known as a selenocentric orbit) is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by spacecraft around the Moon. Th ...

on November 15, 1970 at 22:00 UTC.

Landing and surface operations

The spacecraft soft-landed on the Moon in the

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains", "Sea of Tears") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the colli ...

(''Sea of Rains'') on November 17 at 03:47 UTC. It landed in western Mare Imbrium, about 60 km south of the Promontorium Heraclides. The lander had dual ramps from which the payload, ''Lunokhod 1'', could descend to the

lunar surface The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to " lunar science") is quite different from that of Earth. The Moon lacks a true atmosphere, which eliminates erosion due to weather. It does ...

. At 06:28 UTC the rover moved onto the Moon's surface. The rover would run during the lunar day, stopping occasionally to recharge its batteries via the solar panels. At night the rover hibernated until the next sunrise, heated by the radioactive source. Small craters along its traverse were named unofficially during the mission. The names were officially approved by the IAU in 2012. They are called Albert,

Leonid Leonid (russian: Леонид ; uk, Леонід ; be, Леанід, Ljeaníd ) is a Slavic version of the given name Leonidas. The French version is Leonide. People with the name include: *Leonid Andreyev (1871–1919), Russian playwright a ...

, Kolya,

Valera Valera is a city in Trujillo State in Venezuela, situated between the rivers Momboy and Motatán. The mayor is José Karkom, who has had that post since 2013. The city is home to Italian, Portuguese, Chinese, Colombian and Spanish commu ...

Borya ''Borya'' is a genus of flowering plants in the family Boryaceae, endemic to Australia. , the World Checklist of Selected Plant Families accepted 11 species:Search for "Borya", The Western Australia Flora lists nine current taxa. * '' Bo ...

, Gena, Vitya,

Kostya Constantine ( or ; Latin: ''Cōnstantīnus'', Greek: , ''Kōnstantînos'') is a masculine and feminine (in French for example) given name and surname which is derived from the Latin name ''Constantinus'', a hypocoristic of the first names Constans ...

Igor Igor may refer to: People * Igor (given name), an East Slavic given name and a list of people with the name * Mighty Igor (1931–2002), former American professional wrestler * Igor Volkoff, a professional wrestler from NWA All-Star Wrestling * ...

, Slava, Nikolya, and Vasya. 1970: *November 17 – 22: The rover drove 197 m, returned 14 close-up pictures of the Moon and 12 panoramic views, during 10 communication sessions. It also conducted analyses of the lunar soil. *December 9 – 22: 1,522 m 1971: *January 8 – 20: 1,936 m *February 8 – 19: 1,573 m *March 9 – 20: 2,004 m *April 8 – 20: 1,029 m *May 7 – 20: 197 m *June 5 – 18: 1,559 m *July 4 – 17: 220 m *August 3 – 16: 215 m *August 31 – September 14: 88 m

End of mission and results

Controllers finished the last communications session with ''Lunokhod 1'' at 13:05 UT on September 14, 1971. Attempts to re-establish contact were finally discontinued and the operations of ''Lunokhod 1'' officially ceased on October 4, 1971, the anniversary of

Sputnik 1 Sputnik 1 (; see § Etymology) was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program. It sent a radio signal back to Earth for ...

. During its 322 Earth days of operations, ''Lunokhod 1'' travelled 10,540 metres (6.55 miles) and returned more than 20,000 TV images and 206 high-resolution panoramas. In addition, it performed 25 lunar soil analyses with its RIFMA

x-ray fluorescence X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...

spectrometer and used its penetrometer at 500 different locations.

Current location

The final location of ''Lunokhod 1'' was uncertain until 2010, as lunar laser ranging experiments had failed to detect a return signal from it since 1971. On March 17, 2010, Albert Abdrakhimov found both the lander and the rover in

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 ...

image M114185541RC. In April 2010, the Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) team from the University of California at San Diego used the LRO images to locate the rover closely enough for laser range (distance) measurements. On April 22, 2010 and days following, the team successfully measured the distance several times. The intersection of the spheres described by the measured distances then pinpoint the current location of Lunokhod 1 to within 1 meter. APOLLO is now using ''Lunokhod 1''s reflector for experiments, as they discovered, to their surprise, that it was returning much more light than other reflectors on the Moon. According to a NASA press release, APOLLO researcher Tom Murphy said, "We got about 2,000 photons from Lunokhod 1 on our first try. After almost 40 years of silence, this rover still has a lot to say." By November 2010, the location of the rover had been determined to within about a centimeter. The location near the limb of the Moon, combined with the ability to range the rover even when it is in sunlight, promises to be particularly useful for determining aspects of the Earth–Moon system. In a report released in May 2013, French scientists at the Côte d'Azur Observatory led by Jean-Marie Torre reported replicating the 2010

laser ranging A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...

experiments by American scientists after research using images from the

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, succeedin ...

. In both cases, laser pulses were returned from the ''Lunokhod 1''

retroreflector A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirro ...

.Scientists Use Laser to Find Soviet Moon Rover
space-travel.com, May 2, 2013

Gallery

File:FP2A3576 (23497689198).jpg, Lunokhod 1 in the Museum of Cosmonautics (Moscow) File:Lunokhod 1 - Control panel - Fragment A.jpg, Part of the Lunokhod 1 control panel. Museum of Space and Missile Technology (Saint Petersburg) File:Lunokhod 1 - Control panel - Fragment B.jpg, Part of the Lunokhod 1 control panel.

References

External links

Zarya – ''Lunokhod 1'' chronology

* ttps://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-095A NSSDC Master Catalog: Spacecraft: ''Luna 17''/''Lunokhod 1''
Other Soviet lunar missions

including ''Lunokhod 1''

Old Moon Rover Beams Surprising Laser Flashes to Earth
* {{Orbital launches in 1970 1 1970 in the Soviet Union Missions to the Moon Lunar rovers 1970 robots Robots of the Soviet Union Eight-wheeled robots Solar-powered robots Attached spacecraft Spacecraft launched in 1970 1970 on the Moon