The name of two eight-wheeled robots sent to the Moon by the Soviet Union in November 1970 and January 1973 to perform scientific studies as part of the Luna (Russian for "Moon") program. For some reason almost totally fameless as the first wheeled vehicle on the Moon; that accolade is often incorrectly bestowed on the Rover that Apollo 15 took to the Moon.
Mare Serenitatis is a large, elliptical, relatively flat area of barren rock. Craters surround it and the main 'ice rink' is peppered by dings of impacts by small objects. In common with the whole locality, it enjoys almost perfect serenity: no sounds ever permeate, the landscape is almost never interfered with (indeed, it has remained unchanged for many years) and life would be quite comfortable, save for the lack of any sustenance - respiratory or otherwise - and the occupational hazard of being crushed by rocks falling out of the airless sky. The sides of the Sea rise up many hundreds of metres in a wall, letting out at the south-westerly end into Mare Tranquilitatis.
At the south-westerly end of the Sea, just to the north-east of the outlet, there is relatively small depression, shaped like a wide letter 'U'.
Something stands out, something too regular to be natural. Some bright lines surrounded by small shards
It looks like a huge light bulb has been shattered or something. Some uniformity in the centre surrounded by seeming disarray
and disturbed ground.
A tiny, wispy spider shape sits desolate in the western end of the depression, surrounded by small trinkets that still look like scattered diamonds from here.
Parts of a construction resolve themselves. A platform rests in the dust supported by saucers on the end of four diagonal legs. Nondescript objects surround, filling the vacuum
with stretched shadows and radiation
, as they handshake
with parent devices hundreds of thousands of miles away. Nearby sits a flat, polished object engraved with large glyphs
HERE MAN COMPLETED HIS FIRST EXPLORATION OF THE MOON
DECEMBER 1972 A.D.
MAY THE SPIRIT OF PEACE IN WHICH WE CAME BE REFLECTED IN THE LIVES OF ALL MANKIND
Perhaps this meant something.
Here, over four hundred days* (if you're counting) have passed since these items silently arrived. The other things that were here have gone. They moved, but these things don't. The intervening time has been deeply peaceful and still; alternating extremes of cold and heat with only the most gentle restraints. Plenty of time and space for foil and plastic to sigh, to settle. For the universe to pass by.
Only about a day* had gone since these objects got here when something else changed. The star field is like a painting (the stars twinkle in some places... not here) so changes are clear to anyone paying attention. Very close to the blue eye unblinkingly watching the surface, a star appeared. From nowhere, it popped into being. Or perhaps it came from the eye? It moved; differently to the other, smaller satellites that had passed overhead before (they looked like stars and they moved too, but on a straight path from one side of the "sky" to the other). Of course, this wasn't the first time this had happened. That silver, statuesque quadraped squatting over there started out as a star, just like the one that had just appeared up there. Maybe this new star was another one of them?
Over the following few hours* the star moved some more. It seeped slowly outwards, seeming to speed up a bit. Eventually it moved so far outwards it disappeared over the horizon. Maybe it joined the other satellites, but there was no way of telling as they all looked the same from down there. Another few hours, and one of the satellites - maybe it was the one that appeared before? - started to get bigger. Not much, but definitely bigger than before. Sometimes it looked like bits were coming out of it, too. Little sparkles, flying, fading. It kept crossing the sky, the same direction every time, getting bigger. Still sporadically sprinkling its invisible wake with bright dust. Maybe there would have been sounds if there was air. Later, bigger still, almost a shape, the satellite traversed the sky a final time and didn't return. No sign, but no reappearance.
Late, late on January 16, 1973, Apollo 17's landing site saw the passing of one more fleeting visitor in the form of Lunokhod 2, shortly returning to its indefinite slumber.
Lunokhod (Russian for 'Moonwalker' - thanks Damodred) was part of the Soviet Union's Luna Lunar exploration program which performed several important 'firsts', including the first spacecraft to leave Earth orbit (Luna 1, which also became the first artificial planet), the first to impact the Moon's surface (Luna 2) and the first to photograph the far side of the Moon (Luna 3). The program also included several missions to perform static observation of the lunar surface (Luna 4, 5, 6, 7 & 8) and to return lunar soil to earth for study (Luna 15, 16, 20 & 24). One such mission coincided with Apollo 11, reported by one source as a "last ditch attempt to return lunar soil to earth before United States". It crashed on the Moon.
The missions of interest to this node are Luna 17 and 21, both of which deployed small roving laboratories on the lunar surface. Perhaps with a fresh perspective on space exploration (the political aspect probably diminished significantly, the Soviet Union having now been beaten in the manned Moon race by the US' Apollo program, the Soviet Union set out to perform comprehensive lunar surface studies without concerning themselves with the complications of sending humans there to do it. The decision to send unmanned vehicles can probably also be attributed to the difficulty encountered by the Soviets with getting their manned spacecraft launch system to work safely.
The proxy by which the Soviet Union would explore the Moon was the Lunokhod remote-controlled rover. Probably an artefact of secretive Cold War years, there is no apparent sources of information on the development process of this vehicle, which was done by the Lavochkin Design Bureau (although it was initially undertaken by the Korolev Design Bureau, then passed to Lavochkin for reasons unknown) - also responsible for a number of the anti-aircraft missile systems in use by the USSR. The goals for the Lunokhod rovers were several. High among them were determining the feasibility of performing astronomical observations from the Moon, returning pictures of the surface and studying its composition, and recording local conditions such as x-rays, solar winds and local magnetic fields.
The basic design of the Lunokhod rover was the same for all manufactured. Imagine a large stew pot with four sets of wheels and a convex lid on the top, with various bits sticking out all around it, and that's your basic Lunokhod shape. Lunokhod 1 was 135cm high and weighed about 900kg. The main component was a container shaped like an inverted, severely clipped cone. This enclosed the vehicle's batteries, heat source (a polonium-210 isotope) and instruments. Topping this was a hinged, shallow dome-shaped lid with solar panels on the inside; this would open to gather solar power so the rover could recharge its batteries. Propulsion was provided by eight wheels or rather, eight wheel-shaped frames with wire mesh for tyres - four on each side of the body. Each of these wheels had its own electric motor with independent braking and suspension. Top speed was about 2km/h. I have not found any record of how the steering worked but given that there is no clear steering mechanism (like a steering rack) in any of the photos and with that many wheels, I'm guessing they were contrarotating (the same way tracked vehicles steer).
The sensor suite was comprehensive and constitutes the main differences between the first two vehicles. Amongst the plethora of devices each Lunokhod rover hefted were an astrophotometer (for measuring light levels), a magnetometer and a photodetector. Both vehicles carried television cameras (four on Lunokhod 1, three on Lunokhod 2) as well as an x-ray telescope and an extending scoop for picking up and withdrawing lunar soil inside the rover for testing. Communication was done with two antennae - a conical one for receiving and a helical one for transmitting. Full equipment lists can be found in the sources for this writeup.
The Lunokhod vehicles would require transportation to the Moon, having no means of propulsion themselves except for their wheels, which aren't very helpful in spaceflight. After being launched into orbit by a four-stage Proton 8K82K rocket, a Ye-8 descent/lander stage would ship the rover to the Moon and deliver it to the surface. The Ye-8 lander pretty much defies accurate description. It is basically a series of tubes linked side by side, with slightly larger globes at either end and propellant tanks, with an extending landing leg at each corner. Two sets of boosters provided the propulsion and the braking for landing. Notably the craft also included a homing beacon for reference purposes - possibly triangulation, if enough landers made it - in "future manned missions". To carry a Lunokhod payload, the Ye-8 supported a platform on the top on which the vehicle sat, with a ramp at either end for rover's exit after landing. The reason there was two ramps was to reduce the chances of the rover's path being blocked by boulders on the surface. When folded up, these ramps doubled as retaining barriers.
Two Lunokhod vehicles were delivered to the lunar surface. Four were built but the Luna program was terminated before the fourth one was sent to the Moon; this vehicle resides in a museum. The very first vehicle was blown up when its launcher was accidentally self-destructed on the launch pad. The second vehicle, (presumably renamed) Lunokhod 1, was launched on November 12, 1970 and arrived in lunar orbit on the 15th, landing in the Sea of Rains on the 17th.
After rolling down the ramps the rover toured the Sea of Rains, performing surface experiments and sending back thousands of still photographs, controlled in real time (give or take a few milliseconds) by a team of five controllers in Russia. The rover would operate during the lunar day, stopping if needed to recharge its batteries and hibernating at night, keeping warm with its radioactive source. Lunokhod 1 was intended to operate for three lunar days (each equivalent to a single Earth month) but actually lasted for eleven, officially completing its work on October 4, 1971, anniversary of the launch of Sputnik 1. By this time it had transmitted over twenty thousand still photographs, two hundred video panoramas and had taken and tested 500 samples of the lunar soil.
The next Lunokhod mission (Luna 21), soft-landing on the Moon on January 16, 1973, carried a slightly modified rover that curiously is documented as having the exact same mission goals (word for word) as the previous one. The main difference was in the weight of the rover - lighter by about 60kg than its predecessor. It seems that it carried the same sensing tools as well except for the cameras - it had three instead of four (one of these mast-mounted, for navigation) and also carried four panoramic cameras - and the magnetometer, which was now mounted on a 2.5 metre extendable boom.
Upon arrival, Lunokhod 2 photographed its surroundings from its position on the lander, then about two hours after landing rolled down one of the ramps onto the surface. It then stopped for about ninety minutes for solar charging of its batteries. Afterwards it embarked on exploration of the eastern rim of the Sea of Serenity (only a few tens of miles from Apollo 17's base), again remote-controlled by a team of 5 people back in the Soviet Union and operating during the lunar days. During its 'life' it traversed 37km, over three times that of its predecessor. It returned 86 panoramic images and over eighty thousand television pictures, as well as results of further soil tests and other undisclosed experiments. However it did not run for nearly as long as Lunokhod 1 and on June 4th, less than five months after landing, it was publicly announced that the program was complete. This led to speculation that the vehicle failed or could not be revived after the May-June lunar night. The main basis of this was the fact that the rover was not positioned such that its laser reflector could be used (to determine the rover's position), indicating an accident or failure of some sort.
Lunokhod 2's exploits are still the subject of attention by some individuals, because only a tiny fraction of the 80,000+ images taken were ever released. The others are slowly rotting away somewhere in Russian archives, assuming they weren't destroyed or lost during the collapse of the Soviet Union. The Jet Propulsion Laboratory has had discussion with relevant persons in Russia and has so far recovered a small number of images, though these are not yet available for public view. Based on these, Dr. David West Reynolds of the Phaeton Group (working with NASA and JPL to try to recover this lost image record) has said: "the data return for U.S. scientists [from acquisition and study of the complete photo archive] will be the equivalent of a new mission to the Moon".
Suffice to say that the Lunokhod missions are probably Russia's greatest achievements in space exploration (prior to the remarkable performance of NASA's Spirit and Opportunity Martian rovers, Lunokhod 1 had probably spent more time active on the surface of a remote body than any other manmade vehicle) and are almost certainly not acknowledged enough, though there has been mention of plans to visit the one or both of the vehicles in future lunar exploration missions.
Since I was minus six years old on January 15, 1973 I have almost certainly taken some creative license with the "account", particularly the course the landing craft took, which to be blunt I have no idea about. In a couple of cases I've made assumptions (notably that manmade satellites remained and remain in orbit around the Moon) and also tried to fill in minor blanks in information myself. I'm open to correction, as always.
* - indicates my (probably rather tenuous) use of the lunar timescale. As a reference, a single lunar 'day' is equivalent to a single Earth month. When I use the term 'hour' it is equivalent to one complete Earth rotation.
Williams, Dr. David R (?);
- "Astronomy Picture of the Day"; <http://antwrp.gsfc.nasa.gov/apod/ap990109.html>
- NASA; (Untitled) Map of lunar landing sites; <http://nssdc.gsfc.nasa.gov/planetary/lunar/moon_landing_map.jpg>
Phaeton Group; "Lunokhod Project2; <http://www.phaetongroup.bigstep.com/generic.jhtml?pid=5>
(Author unknown); "The VSM: Lunokhod-3"; <http://vsm.host.ru/luno3.htm>
National Space Development Agency of Japan; "Moon, Planet Probes"; <http://space.nasda.go.jp/db/kaihatu/wakusei/wakusei_e/runa_e.html>
The Lunar Republic; "Full Moon Atlas: Sector C-5
Northern Mare Serenitatis"; <http://www.lunarrepublic.com/atlas/sections/c5.shtml>
(Author unknown); "APOLLO 17 LANDING SITE OVERVIEW"; http://www.lpi.usra.edu/expmoon/Apollo17/A17_lsite.html (Apollo 17 landing site)
(Author unknown); "Apollo 17"; <http://users.skynet.be/sky93291/site/eng/apollo/project/a17.htm>
Livingston, Jason C.; "Apollo 17 Landing Site"; <http://www.geocities.com/jassdude/apollo17.html>
Arnett, Bill; "The Moon"; <http://seds.lpl.arizona.edu/nineplanets/nineplanets/luna.html>
- "Luna 17/Lunokhod 1"; ≶thttp://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1970-095A>
- "Luna 21/Lunokhod 2"; http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1973-001A
Terry Pratchett's "Wings" (I think) - a bit of inspiration, vague though it is since it must be six or seven years since I read the book.
- "Proton 8K82K / 11S824"; <http://www.astronautix.com/lvs/pro1s824.htm>
- "Luna Ye-8"; <http://www.astronautix.com/craft/lunaye8.htm>