Lunokhod programme

The Lunokhod mission diagram.

Lunokhod (Russian Луноход, "Moonwalker") 1 and 2 were a pair of Soviet robotic lunar rovers landed on the Moon in 1970 and 1973, respectively. They were in operation conterminously with the Zond series of flyby missions. The Lunokhod missions were primarily designed to explore the surface and return pictures. This complemented the Luna series of missions that were intended to be sample return missions and orbiters. They were designed by Alexander Kemurdjian at NPO Lavochkin. It wouldn't be until 1996 with the Mars Pathfinder that another remote controlled vehicle would be put on an extraterrestrial body.

Development

Lunokhod's original primary mission was the survey of sites for later manned landings and lunar bases. Also, it was intended that the spacecraft would provide a radio beacon for precision landings of manned spacecraft. Originally, the vehicle was designed to be used by a single cosmonaut between primary and back-up LK Landers in case of failure. Instead, it was used for remote exploration of the lunar surface after the successful Apollo manned lunar landings.

In summer 1968, at the KIP-10(КИП-10) in the secret village of Shkolnoye, near Simferopol, a lunodrom (moondrome) was built. It covered an area of one hectare (120 meters by 70 meters) and was very similar to some parts of the lunar surface. It was constructed using more than 3,000 cubic meters of soil, and included 54 craters up to 16 m in diameter and around about 160 rocks of various sizes. The whole area was covered with bricks, painted in gray and black. It was used to analyze problems with the Lunokhod chassis.

After years of secret engineering development and training, the first Lunokhod was launched on February 19, 1969. However, within a few seconds the rocket disintegrated and the first Lunokhod was lost. The rest of the world did not learn of the rocket's valuable payload until years later.

Lunokhod 1

Main article: Lunokhod 1

File:Lunokhod 1.jpg

Lunokhod 1 robot vehicle

After the destruction of the original Lunokhod, Soviet engineers began work immediately on another lunar vehicle. Lunokhod 1 (Луноход, moon walker in Russian) 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. Lunokhod was the first roving remote-controlled robot to land on another world.

Luna 17 was launched on 1970-11-10 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 manoeuvres (on November 12 and 14) it entered lunar orbit on 1970-11-15 at 22:00 UTC.

The spacecraft soft-landed on the Moon in the Sea of Rains on 1970-11-17 at 03:47 UTC. The lander had dual ramps from which the payload, Lunokhod 1, could descend to the lunar surface. At 06:28 UT the rover moved onto the moon's surface.

To be able to work in vacuum a special fluoride based lubricant was used for the mechanical parts and the electric motors (one in each wheel hub) were enclosed in pressurised containers.

The rover would run during the lunar day, stopping occasionally to recharge its batteries via the solar panels. At night the rover would hibernate until the next sunrise, heated by the radioactive energy source.

Rover description

File:Lunokhod color.jpg

Model of Lunokhod series Soviet Moon exploration robot vehicle

Detail of Lunokhod's wheels

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 2.3 metres. Lunokhod 1 was equipped with a cone-shaped antenna, a highly directional helical antenna, four television cameras, and special extendable devices to impact the lunar soil for density measurements and mechanical property tests.

An X-ray spectrometer, an X-ray telescope, cosmic ray detectors, and a laser device were also included. The vehicle was powered by batteries which were recharged during the lunar day by a solar cell array mounted on the underside of the lid. During the lunar nights, the lid was closed and a polonium-210 heat source kept the internal components at operating temperature.

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 (4 ft 11 in) wide and had 8 wheels each with an independent suspension, motor and brake. The rover had two speeds, ~1 km/h and ~2 km/h (0.6 mph and 1.2 mph).

Payload

• Cameras (two TV & four panoramic telephotometers)
• RIFMA X-ray fluorescence spectrometer
• RT-1 X-ray telescope
• PrOP odometer/penetrometer
• RV-2N radiation detector
• TL laser retroreflector

Lunokhod 2

Main article: Lunokhod 2

File:Lunokhod2.jpg

Lunokhod 2 robot vehicle

Lunokhod 2 was the second of two unmanned lunar rovers landed on the Moon by the Soviet Union as part of the Lunokhod program.

The SL-12/D-1-e launcher put the spacecraft into Earth parking orbit in 1973-01-08, followed by translunar injection. On 1973-01-12, Luna 21 was braked into a 90 by 100 km (approx. 56 by 62 mile) orbit about the Moon.

The Luna 21 spacecraft landed on the Moon and deployed the second Soviet lunar rover Lunokhod 2. 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-rays, measure local magnetic fields, and study mechanical properties of the lunar surface material.

Landing occurred on 1973-01-15, 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 1973-01-16 and took pictures of the Luna 21 lander and landing site.

Rover description

Lunokhod 2 was equipped with three slow-scan television cameras, one mounted high on the rover for navigation, which could return high resolution images at different rates—3.2, 5.7, 10.9 or 21.1 seconds per frame (not frames per second). These images were used by a five-man team of controllers on Earth who sent driving commands to the rover in real time. There were 4 panoramic cameras mounted on the rover.

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 radioactive heat source was used to keep the rover warm during the long lunar nights.

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.

Payload

• Cameras (three TV & four panoramic telephotometers)
• RIFMA-M X-ray fluorescence spectrometer
• X-ray telescope
• PROP odometer/penetrometer
• RV-2N-LS radiation detector
• TL laser retroreflector
• AF-3L UV/visible astrophotometer
• SG-70A magnetometer
• Rubin 1 photodetector

Lunokhod 3

Lunokhod 3 was built, but never flown to the Moon. It remains at the NPO Lavochkin museum.

Results

During its 322 Earth days of operations, Lunokhod 1 traveled 10.5 km and returned more than 20,000 TV images and 206 high-resolution panoramas. In addition, it performed twenty-five soil analyses with its RIFMA x-ray fluorescence spectrometer and used its penetrometer at 500 different locations.

Lunokhod 2 operated for about 4 months, covered 37 km (23 miles) of terrain, including hilly upland areas and rilles, and currently holds the record for longest distance of travel of any extraterrestrial vehicle. It 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.

For comparison, the modern NASA rovers Spirit and Opportunity had, by their first anniversary in 2005, traveled a total of 6 km and transmitted a total of 62,000 images. (Spirit and Opportunity are smaller, three decades more advanced, and had already lasted four times longer than anticipated by this point.) Although the prize for longevity must go to the NASA twins, for having lasted over three and one-half years, the technical achievements of the Lunokhod program were nothing short of amazing by any standard.

Chernobyl legacy

According to a french documentary TV film "Tank on the Moon" by Jean Afanassieff, the Lunokhod design returned to limelight 15 years later due to the Chernobyl nuclear powerplant disaster. The east german made remote controlled bulldozers available to soviet civil defence troops weighed dozens of tons, too heavy to operate on the remaining parts of the partially collapsed reactor building roof. Human labourers could not be employed effectively to shovel debris, since workshifts were limited to tiny 90 second (!) intervals due to intensive ionising radiation.

Lunokhod designers were called back from retirement and in two weeks time they produced a field-usable, six wheeled, remote control vehicle prototype that was light enough to work on the weakened roof. Since the original Lunokhod moon rovers used nuclear decay heatsources for internal rack climate control, their electronic systems were already hardened to resist radiation. This benefit allowed the 1986 designers to quickly come up with a derived vehicle type for nuclear disaster recovery work. Eventually two such six-wheeled rovers were delivered to the Chernobyl accident zone and proved very useful for remotely operated debris clearing work, saving lives and earning decorations for the designers.

Present locations and ownership

The final location of Lunokhod 1 is uncertain by a few kilometers . Lunar laser ranging experiments have failed to detect a return signal from it since the 1970s.

Lunokhod 2 continues to be detected by lunar laser ranging experiments and its position is known to sub-meter accuracy. Ownership of Lunokhod 2 and the Luna 21 lander was sold by the Lavochkin Association for $68500 in December 1993 at a Sotheby's auction in New York (although 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:

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 has more recently confirmed that he is the owner of Lunokhod 2 .

See also

• Exploration of the Moon
• Google Lunar X PRIZE
• Mars Exploration Rovers
• Mars Pathfinder

References

• Vinogradov, A. P. (ed.), (1971). Peredvizhnaya Laboratoriya na Lune Lunokhod-1. Tom 1. Moscow, Nauka.
• Barsukov, V. L. (ed.), (1978) Peredvizhnaya Laboratoriya na Lune Lunokhod-1. Tom 2. Moscow, Nauka.
• The Other Moon Landings by Andy Chaikin, Smithsonian Air & Space magazine February/March 2004.

External links

• Lunar and Planetary Department Moscow University
• Exploring the Moon (1969-1976) - a diary of significant events in Soviet lunar exploration, including those associated with the Lunokhod programme
• Don P. Mitchell's catalog of Soviet Moon Images including many from the Lunokhod programme
• Lunakhod article at Lunarpedia
• Tests of breadboard models of lunokhods on moonodrome(лунодром - moondrome in Russian) near Simferopol in 1969
• Remote control lunokhods and planetrovers in Russian.
• Crews lunokhodsin Russian.