Lunokhod 2
Encyclopedia
Lunokhod 2 was the second of two unmanned lunar rover
s landed on the Moon
by the Soviet Union
as part of the Lunokhod program.
The Luna 21
spacecraft landed on the Moon and deployed the second Soviet lunar rover
(Lunokhod 2) in January, 1973. 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
, observe solar X-ray
s, measure local magnetic field
s, and study the soil mechanics
of the lunar surface material
.
The rover stood 135 cm (4 ft 5 in) high and had a mass of 840 kg (1,850 lb). It was about 170 cm (5 ft 7 in) long and 160 cm (5 ft 3 in) wide and had 8 wheels each with an independent suspension
, electric motor
and brake
. The rover had two speeds, ~1 km/h and ~2 km/h (0.6 mph and 1.2 mph). Lunokhod 2 was equipped with three television cameras, one mounted high on the rover for navigation, which could return high resolution images at different frame rate
s—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
was used to keep the rover warm during the long lunar nights. There were four panoramic cameras mounted on the rover. Scientific instruments included a soil mechanics
tester, solar X-ray experiment, an astrophotometer to measure visible and ultraviolet
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
(Rubin-1) for laser detection experiments, and a French-supplied laser corner reflector
. The lander carried a bas relief of Lenin and the Soviet coat of arms
. The lander and rover together massed 1814 kg.
followed by translunar injection. On January 12, 1973 Luna 21 was braked into a 90 by 100 km (56 by 62 mile) lunar orbit
. On January 13 and January 14, the perilune was lowered to 16 km (9.9 mi) altitude.
. At an altitude of 750 m (2,460 ft) the main thrusters began firing, slowing the fall until a height of 22 m (72 ft) was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was 1.5 m (5 ft) 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 Luna 21 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, stopping occasionally to recharge its batteries with the solar panels. At night the rover hibernated until the next sunrise, heated by the radioactive source.
More recently, Alexander Basilevsky related an account where on May 9, 1973, the rover's open lid touched a crater wall and became covered with dust. When the lid was closed for the lunar night, this dust (a very good insulator) was dumped on to the radiator
s. The following lunar day, controllers saw the internal temperature of the Lunokhod climb as it was unable to cool itself, eventually rendering the rover inoperable.
areas and rille
s, and sent back 86 panoramic images and over 80,000 TV pictures. The 37 km journey remains the longest any robotic rover has ever been driven on another celestial body. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time.
s and its position is known to sub-meter accuracy. On March 17, 2010 Phil Stooke, a professor at the University of Western Ontario
announced that he had located Lunokhod 2's final resting place in photographs made by the Lunar Reconnaissance Orbiter
.
Association for $68,500 in December 1993 at a Sotheby's
auction in New York. (The catalog incorrectly lists lot 68A as Luna 17/Lunokhod 1).
The buyer was computer gaming entrepreneur and astronaut's son Richard Garriott
(also known as Lord British), who stated in a 2001 interview with Computer Games Magazine
's Cindy Yans that:
Richard Garriott
has more recently confirmed that he is the owner of Lunokhod 2.
Rover (space exploration)
A rover is a space exploration vehicle designed to move across the surface of a planet or other astronomical body. Some rovers have been designed to transport members of a human spaceflight crew; others have been partially or fully autonomous robots...
s landed on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
as part of the Lunokhod program.
The Luna 21
Luna 21
-External links:*...
spacecraft landed on the Moon and deployed the second Soviet lunar rover
Rover (space exploration)
A rover is a space exploration vehicle designed to move across the surface of a planet or other astronomical body. Some rovers have been designed to transport members of a human spaceflight crew; others have been partially or fully autonomous robots...
(Lunokhod 2) in January, 1973. The primary objectives of the mission were to collect images of the lunar surface, examine ambient light
Available light
In photography and cinematography, available light or ambient light refers to any source of light that is not explicitly supplied by the photographer for the purpose of taking photos. The term usually refers to sources of light that are already available naturally or artificial light already being...
levels to determine the feasibility of astronomical observations from the Moon, perform laser ranging experiments from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, observe solar X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s, measure local magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
s, and study the soil mechanics
Soil mechanics
Soil mechanics is a branch of engineering 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 and particles but soil may also contain organic solids, liquids, and gasses and other...
of the lunar surface material
Lunar soil
Lunar soil is the fine fraction of the regolith found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil...
.
Lunokhod 2 rover and subsystems
Independent suspension
Independent suspension is a broad term for any automobile suspension system that allows each wheel on the same axle to move vertically independently of each other. This is contrasted with a beam axle, live axle or deDion axle system in which the wheels are linked – movement on one side affects...
, electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
and brake
Brake
A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....
. The rover had two speeds, ~1 km/h and ~2 km/h (0.6 mph and 1.2 mph). Lunokhod 2 was equipped with three television cameras, one mounted high on the rover for navigation, which could return high resolution images at different frame rate
Frame rate
Frame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
s—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
Photovoltaic module
A solar panel is a packaged, connected assembly of solar cells, also known as photovoltaic cells...
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 unit
Radioisotope heater units are small devices that provide heat through radioactive decay. They are similar to tiny radioisotope thermoelectric generators , and normally provide about one watt of heat each, derived from the decay of a few grams of plutonium 238, although other radioactive isotopes...
was used to keep the rover warm during the long lunar nights. There were four panoramic cameras mounted on the rover. Scientific instruments included a soil mechanics
Soil mechanics
Soil mechanics is a branch of engineering 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 and particles but soil may also contain organic solids, liquids, and gasses and other...
tester, solar X-ray experiment, an astrophotometer to measure visible and ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
light levels, a magnetometer
Magnetometer
A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...
deployed in front of the rover on the end of a 2.5 m
Metre
The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...
(8 ft 2 in) boom, a radiometer
Radiometer
A radiometer is a device for measuring the radiant flux of electromagnetic radiation. Generally, the term radiometer denotes an infrared radiation detector, yet it also includes detectors operating on any electromagnetic wavelength....
, a photodetector
Photodetector
Photosensors or photodetectors are sensors of light or other electromagnetic energy. There are several varieties:*Active pixel sensors are image sensors consisting of an integrated circuit that contains an array of pixel sensors, each pixel containing a both a light sensor and an active amplifier...
(Rubin-1) for laser detection experiments, and a French-supplied laser corner reflector
Corner reflector
A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat surfaces, which reflects waves back directly towards the source, but shifted . Unlike a simple mirror, they work for a relatively wide-angle field of view. The three intersecting surfaces often have...
. The lander carried a bas relief of Lenin and the Soviet coat of arms
Coat of arms of the Soviet Union
The State Emblem of the Soviet Union was adopted in 1923 and was used until the dissolution of the Soviet Union in 1991. Although it technically is an emblem rather than a coat of arms, since it does not follow heraldic rules, in Russian it is called герб , the word used for a traditional coat of...
. The lander and rover together massed 1814 kg.
Mission profile
The SL-12/D-1-e launcher put the spacecraft into Earth parking orbitParking orbit
A parking orbit is a temporary orbit used during the launch of a satellite or other space probe. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory...
followed by translunar injection. On January 12, 1973 Luna 21 was braked into a 90 by 100 km (56 by 62 mile) lunar orbit
Lunar orbit
In astronomy, lunar orbit refers to 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 various manned or unmanned spacecraft around the Moon...
. On January 13 and January 14, the perilune was lowered to 16 km (9.9 mi) altitude.
Landing and surface operations
On January 15 after 40 orbits, the braking rocket was fired at 16 km (9.9 mi) altitude, and the craft went into free fallFree fall
Free fall is any motion of a body where gravity is the only force acting upon it, at least initially. These conditions produce an inertial trajectory so long as gravity remains the only force. Since this definition does not specify velocity, it also applies to objects initially moving upward...
. At an altitude of 750 m (2,460 ft) the main thrusters began firing, slowing the fall until a height of 22 m (72 ft) was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was 1.5 m (5 ft) above the surface, where the engine was switched off. Landing occurred at 23:35 UT in Le Monnier crater
Le Monnier (crater)
Le Monnier is the remnant of a lunar crater that has been partly inundated by lava flows. It is located on the eastern edge of Mare Serenitatis, and the western part of the rim is missing so that it now forms a large bay. To the north is the crater Chacornac....
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 Luna 21 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, 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, 1973 to February 23, 1973: The rover drives 9,086 metres further
- March 11, 1973 to March 23, 1973: The rover drives 16,533 metres further
- April 9, 1973 to April 22, 1973: The rover drives 8,600 metres further
- May 8, 1973 to June 3, 1973: The rover drives 880 metres further
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 where on May 9, 1973, the rover's open lid touched a crater wall and became covered with dust. When the lid was closed for the lunar night, this dust (a very good insulator) was dumped on to the radiator
Radiator
Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in automobiles, buildings, and electronics...
s. The following lunar day, controllers saw the internal temperature of the Lunokhod climb as it was unable to cool itself, eventually rendering the rover inoperable.
Results
Lunokhod 2 operated for about 4 months, covered 37 km (23 mi) of terrain, including hilly uplandHighland (geography)
The term highland or upland is used to denote any mountainous region or elevated mountainous plateau. Generally speaking, the term upland tends to be used for ranges of hills, typically up to 500-600m, and highland for ranges of low mountains.The Scottish Highlands refers to the mountainous...
areas and rille
Rille
Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...
s, and sent back 86 panoramic images and over 80,000 TV pictures. The 37 km journey remains the longest any robotic rover has ever been driven on another celestial body. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time.
Current status
Lunokhod 2 continues to be detected by lunar laser ranging experimentLunar laser ranging experiment
The ongoing Lunar Laser Ranging Experiment measures the distance between the Earth and the Moon using laser ranging. Lasers on Earth are aimed at retroreflectors planted on the moon during the Apollo program, and the time for the reflected light to return is determined...
s and its position is known to sub-meter accuracy. On March 17, 2010 Phil Stooke, a professor at the University of Western Ontario
University of Western Ontario
The University of Western Ontario is a public research university located in London, Ontario, Canada. The university's main campus covers of land, with the Thames River cutting through the eastern portion of the main campus. Western administers its programs through 12 different faculties and...
announced that he had located Lunokhod 2's final resting place in photographs made by the Lunar Reconnaissance Orbiter
Lunar Reconnaissance Orbiter
The Lunar Precursor Robotic Program is a program of robotic spacecraft missions which NASA will use to prepare for future human spaceflight missions to the Moon. Two LPRP missions, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite , were launched in June 2009...
.
Present ownership
Ownership of Lunokhod 2 and the Luna 21 lander was sold by the LavochkinLavochkin
NPO Lavochkin is a Russian aerospace company. It is a major player in the Russian space program, being the developer and manufacturer of the Fregat upper stage, as well as interplanetary probes such as Phobos Grunt...
Association for $68,500 in December 1993 at a Sotheby's
Sotheby's
Sotheby's is the world's fourth oldest auction house in continuous operation.-History:The oldest auction house in operation is the Stockholms Auktionsverk founded in 1674, the second oldest is Göteborgs Auktionsverk founded in 1681 and third oldest being founded in 1731, all Swedish...
auction in New York. (The catalog incorrectly lists lot 68A as Luna 17/Lunokhod 1).
The buyer was computer gaming entrepreneur and astronaut's son Richard Garriott
Richard Garriott
Richard Allen Garriott is a British-American video game developer and entrepreneur.He is also known as his alter egos Lord British in Ultima and General British in Tabula Rasa...
(also known as Lord British), who stated in a 2001 interview with Computer Games Magazine
Computer Games Magazine
Computer Games Magazine was a computer gaming print magazine. It was formerly Computer Games Strategy Plus, and before that, Strategy Plus, which had been founded as Games International in the UK in 1988. While its initial focus was on strategy games, it covered a wide range of game genres...
's Cindy Yans that:
- I purchased Lunakod 21 [sic] 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!
Richard Garriott
Richard Garriott
Richard Allen Garriott is a British-American video game developer and entrepreneur.He is also known as his alter egos Lord British in Ultima and General British in Tabula Rasa...
has more recently confirmed that he is the owner of Lunokhod 2.
See also
- Luna 21Luna 21-External links:*...
- Lunar Laser Ranging ExperimentLunar laser ranging experimentThe ongoing Lunar Laser Ranging Experiment measures the distance between the Earth and the Moon using laser ranging. Lasers on Earth are aimed at retroreflectors planted on the moon during the Apollo program, and the time for the reflected light to return is determined...
- Lunokhod 1Lunokhod 1Lunokhod 1 was the first of two unmanned lunar rovers landed on the Moon by the Soviet Union as part of its Lunokhod program. The spacecraft which carried Lunokhod 1 was named Luna 17...