Special Sub-Topic: Lunokhod Moon Rover
|What does 'Lunokhod' literally mean?|
Moon walker. The 'Lunokhod' or 'moon walker' was built under the direction Georgi Babakin of the Lavochkin design bureau after the Institute for Tractor and Agricultural Machinery deemed it impossible to build. It was a typically robust Soviet design weighing in at 756 kg and was part of the Ye-8 series of Luna exploration probes. It was originally designed to scout potential landing sites for the planned manned landing on the moon and act as transport for the cosmonaut to travel to a backup LK lander in case the original one became disabled.
|How many wheels did the Lunokhod use to travel across the lunar surface?|
Eight. Despite its name, Lunokhod did not walk across the surface but was propelled by eight independently driven wheels. Power was supplied by storage batteries which were recharged by solar cells. The eight wheeled chassis supported a pressurised bathtub shaped body which contained cameras, transmitters and scientific instruments. The lid of the body opened up to expose the solar cells on its underside and a thermal radiator on the top of the bathtub to keep the instrumentation cool during the lunar day. During the 14 day lunar night the lid was closed and the instrumentation kept at optimum temperature by a radioactive Polonium heat source.
|How many Lunokhods successfully landed on the moon?|
Two. There were two successful Lunokhod missions. The original Lunokhod landed on the moon on November 1970 and Lunokhod 2 was deployed in January 1973. The first attempt to launch a Lunokhod was aborted in February 1969 when the UR 500 Proton launch vehicle failed as excessive vibration tore off the launch shroud and the rocket exploded scattering debris 15 km downrange. For months afterwards, teams tried to recover the Polonium nuclear isotope intended to keep instrumentation in the Lunokhod pressurised container warm during the lunar night. It later transpired that some insufficiently briefed local troops had found the container and were using it to keep their hut warm during a particularly cold winter! This failure was the start of an incredibly unlucky string of disasters which afflicted the Soviet moon programme at a time when they were trying to upstage the American Apollo programme during the first half of 1969.
Lunokhod 3 was never flown after the decision was taken to wind down the Ye-8 moon programme in 1973 and is on display at the Lavochkin museum.
|The Lunokhods were launched as part of the automatic exploration 'Luna' series. Which 'Luna' mission deployed the original Lunokhod?|
Luna 17. Luna 17 soft landed Lunokhod on November 17, 1970 after being in lunar orbit for two days before firing a retrorocket which gently lowered the landing stage to the surface as a radar altimeter checked the landing site. These landing stages (KT) were the same design as the ones being used for sample return missions and lunar orbiters which were also being flown at this time. Luna 17's landing stage was modified to carry Lunokhod with two ramps on either side for the robot to trundle down onto the surface after landing. The two ramps enabled the robot to continue its mission in case one was obstructed by a rock or other obstacle.
Luna 9 was the first probe to achieve a soft landing on the moon in January 1966. Luna 10 was the first probe to be placed into lunar orbit in March 1966
Luna 16 was the first probe to automatically return lunar soil to earth in September 1970.
|Lunokhod was successfully deployed where on November 17 1970?|
Sea of Rains. Luna 17 deployed the first Lunokhod rover in the semi-circular Sea of Rains, a basin in the NW corner of the Ocean of Storms. Everyone was expecting another sample return mission so it was a surprise when this contraption looking like a machine from a Jules Verne novel started trundling across the lunar surface. The eight wheeled robot supporting a trashcan-like body with its lid open and guided by a pair of goggle-like stereo TV cameras quickly endeared itself to the public. The tracks it made were the first wheel marks on another world! These preceded those made by the hand cart Modularised Equipment Transporter (MET) used by Shepard and Mitchell to transport equipment during the Apollo 14 mission the following January.
|How many operators were required to drive Lunokhod during its explorations of the lunar surface?|
Five. A team of five based at Simferopol in the Crimea near the big tracking dishes at Yevpatoria operated Lunokhod. Two teams took alternating shifts and each consisted of a commander, a driver, a navigator, an engineer, and a radio/antenna man. Operating Lunokhod from 380,000 km away was a tense business requiring a high degree of co-ordination between the team members. During the first few days excitement was such that scientists and journalists crowded mission control and began offering advice like "Mind that crater!" or "He's going to crash into that rock!" The situation was so tense that when the drivers' pulses reached 140, Babakin the director, finally had enough and ordered the chorus of back seat drivers out of the control room to reduce the stress on his team. It was quickly determined that the cameras were mounted too low on the body of Lunokhod with the view being similar to someone crawling across the ground on their hands and legs and the 20 second per frame transmission rate was too slow as drivers had to memorise features a full third of a minute before they were on top of them. These faults were rectified on Lunokhod 2. Also operations had to be halted at lunar noon (two earth days) as the landscape was washed out and there were no shadows to pick out features.
|How long did the first Lunokhod operate?|
10 months. The amazing Lunokhod continued to operate for just over 10 months. It had been designed for a three month mission. During that time it travelled over 10 km, sent back 20,000 pictures including 200 panoramas, and X-rayed the soil at 25 locations. The driving teams and scientists were exhausted having worked 10 hour shifts 14 days at a time (1 lunar day) with a break at lunar noon. They took breaks and reviewed their data during the 14 day lunar night. Initially Babakin's team were under pressure from Pravda and Tass to set new distance records which irked the scientific team who wanted to stop and investigate interesting rocks and other features. At one point Babakin remarked to the science team leader that this was a Lunokhod not a Lunostop! The little robot finally died on 4th October when its Polonium heat source gave out and pressure rapidly dropped in its sealed container with the wheels stopping and TV pictures and signals being cut off. Its accomplishments were even more remarkable when it was later revealed that the brakes had failed in the 'on' position quite early in the mission and it had been operating against their friction for most of the time!
|On 16 January __________ Lunokhod 2 was successfully delivered to the moon by Luna 21.|
1973. Lunokhod 2 was targeted to land at Le Monier crater, a transitional zone between lunar mares (seas) and highland continental country in early 1973. This was only 150 km from the Taurus Littrow valley which had just been visited by the final Apollo 17 mission the previous December. Lunokhod 2 weighed 850 kg, more than 100 kg heavier than its predecessor reflecting the improvements that had been incorporated since the previous mission. It had two speeds, could traverse steeper slopes and larger holes, had twice the range, and TV pictures were now transmitted every 3.2 secs with the cameras mounted higher, a great improvement for the drivers. It also carried out extra scientific experiments. The rover carried out a close inspection of its landing stage and craters in the immediate vicinity before closing its lid and shutting down at the end of the first lunar day. The rover continued its exploration for the next three months when quite suddenly Radio Moscow announced that its programme had been completed! No further explanation was offered for the seemingly premature demise of the rover. It was only 30 years later that an explanation was offered. It seems the drivers had gone down into a particularly steep crater and as they tried to exit it the lid had scraped the side of the crater depositing lunar soil on the solar cells. The effects were not immediately obvious with only some loss of electrical power but when the lid was closed for the night soil was dumped onto the radiators which control temperatures in the pressurised section. When the lid was opened the following day the radiators could not function and quickly rising temperatures caused Lunokhod 2 to expire.
|How many kilometres did Lunokhod 2 travel during its mission?|
37 km. Lunokhod 2 travelled 37 km and sent back 80,000 TV pictures including 86 panoramas during its three months of operation. It travelled about seven times faster than its predecessor because of the improved views the drivers had and conducted a rather hazardous investigation along the edge of a rille called Fossa Recta negotiating large boulders and slopes up to 25 degrees. At one point it climbed a hill 400m high and took a photograph of the Taurus peaks 60 km away with a sickle shaped earth rising above.
|Lunokhod was sold off at an auction in 1993.|
True. Believe it or not this is true. In the wake of the demise of the Soviet Union and the financial meltdown that followed Lunokhod went under the hammer at Sotheby's for the sum of $68,500. The sale went with the stipulation that the purchase was: 'Resting on the moon to be collected by the purchaser'.
In recent years new information has been forthcoming on Lunokhod and other aspects of the Soviet lunar programme which has filled in many of the gaps on what seemed at the time to be a confusing series of missions. For a great read on this subject I thoroughly recommend 'Soviet and Russian Lunar Exploration' by Brian Harvey.
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