Current Issue
May 2014 magazine cover

Save 47% off the cover price!

Artist's conception of the Lunokhod rover about to descend ramps from the landing module. (NASA History Office)

The Other Moon Landings

The Soviets lost the moon race but won a dram of glory with the first robotic craft to roam another world.

THERE WAS A TIME, in the early years of the space race, when the moon seemed to be Soviet territory. The first man-made object to reach the moon was the Soviet Luna 2 probe, which struck the surface in September 1959. A month later Luna 3 gave humanity its first glimpse of the moon’s far side. In February and March 1966, Luna 9 transmitted the first pictures from the lunar surface and Luna 10 orbited the moon. And in September 1968 a handful of turtles and simpler organisms aboard the Soviets’ Zond 5 became the first living beings to make a circumlunar voyage. By then, planners within the USSR were hopeful that the first words spoken from the surface of the moon would be Russian.

From This Story

But when a trio of U.S. astronauts orbited the moon in December 1968, that hope all but died. Apollo 8’s triumph sent a shock wave through the Soviet space hierarchy, which realized that the political victory of landing the first men on the moon would soon go to the Americans. Soviet leaders wondered what to do in response. Ultimately they focused on robotic missions, which were not only easier and cheaper than piloted lunar voyages but would also give them a chance to spin their space program as a scientific venture, rather than one conducted just for the sake of Cold War competition. The Luna missions were to include an automated sample-return probe; the government ordered that effort accelerated.

On a second attempt after a June 1969 launch failure, Luna 15 began circling the moon on July 17, 1969, two days before the Apollo 11 astronauts themselves entered lunar orbit for the first manned landing attempt. If all went according to plan, the Soviet craft could be back on Earth with a container of lunar soil a day after the astronauts returned—close enough to upstage the U.S. achievement, or, if Apollo 11 failed, to give the Soviets an outright triumph. But on July 21, as Neil Armstrong and Buzz Aldrin were preparing to lift off from the Sea of Tranquillity, Luna 15, while making its descent into the Sea of Crises, smashed into a mountain. Not until September 20, 1970, did Luna 16 alight safely on the Sea of Fertility and carry out a sample-return mission.

Luna 16 was a dazzling technical achievement, but it was also clear that, compared with America’s manned lunar missions, it didn’t measure up scientifically. By this time, two teams of Apollo astronauts had brought back a total of over 120 pounds of rock and dust. Luna 16’s return was just 3.5 ounces. Still, geologist Alexander “Sasha” Basilevsky of the Vernadsky Institute for Geochemistry recalls that the sense of competition with the Americans was still very much alive. “These samples would be our samples,” Basilevsky says. “We would study them. If you don’t send anything [to the moon], you’re just defeated.”  But Basilevsky was already looking forward to a very different kind of mission—one that would turn him into a virtual lunar explorer.

With the Soviet manned landing effort in limbo, a rover was slated to substitute for human explorers. Its name was Lunokhod, Russian for “moonwalker.” The first challenge chief designer Georgiy Babakin and his team at the Lavochkin Design Institute faced was protecting their machine from the temperature extremes it would encounter on the moon. Lunokhod would have to operate in the blistering heat of the two-week lunar day, up to 240 degrees Fahrenheit, and survive the frigid two-week lunar night, when temperatures plummet to 290 degrees below zero. To control temperatures inside the rover, designers chose a tub-like pressurized shell, topped by a lid that could be opened and closed on command from Earth. The lid, which contained an array of solar cells for charging the rover’s batteries, would be kept open during the day so the cells could absorb solar energy. Before sunset the lid would be closed, and the rover would go into hibernation as radioactive polonium-210 warmed vital components inside. For locomotion, designers at the All Union Science and Research Institute of Transportation tested a variety of designs for the seven-foot-long rover, including tractors, walkers, and even jumpers, but in the end chose eight individually controlled wheels, each supported by spokes and covered with wire mesh to aid mobility in powdery soil.

Once Lunokhod was on the moon, the success of the mission would be in the hands of two five-man crews chosen from the military’s missile defense corps. In the spring of 1968, candidates were carefully screened for engineering expertise, capacity for prolonged mental focus and attention, quick reaction times, the ability to process information quickly, good long-term and short-term memory, and vision and hearing. So thorough was the selection process that some of the men thought they were being recruited for the cosmonaut corps, until they were told of their real mission: to operate the first wheeled vehicle on the surface of another world.

Only one member of each crew would drive the rover. Behind him would sit the crew commander, who would oversee the driver’s handling of the rover. Joining them in the control room would be a navigator, a radio antenna operator, and the flight engineer, who would monitor the rover’s systems. Each crew would operate the rover for two hours; then the other crew would take control. At the Lavochkin plant the crew members familiarized themselves with every aspect of the craft and spent hours practicing with a mockup on a specially constructed “lunodrome” near the mission’s control center, in the Crimean city of Simferopol.

An exploding booster doomed the initial launch attempt in February 1969, but the second try landed Lunokhod 1 at the western edge of the moon’s Sea of Rains on November 17, 1970. Under driver Gabdulkhay Latypov’s control, the rover descended one of the two ramps extended from the descent stage and stood on the moon’s surface, ready to begin its expedition.

Gripping in his right hand a control stick that resembled a car’s gearshift, Latypov could make the rover go forward at one of two speeds (0.5 or 1.2 mph) or go in reverse. He and Vyacheslav Dovgan, the other crew’s driver, turned the craft not by rotating the wheels, which were fixed, but by slowing down one side relative to the other, the way one steers a tank.

Latypov and Dovgan’s only guidance came from a monitor, which displayed images from Lunokhod’s two low-resolution television cameras. To any video game enthusiast it sounds simple—but this was nothing like a video game. The cameras did not send a continuous stream of images, but rather single frames, like a slide show, at intervals that varied from seven to 20 seconds. And because radio signals took three seconds to travel round trip between Earth and the moon, the driver didn’t see the results of his actions for many long moments. For this reason, if crew commanders Nikolai Yeremenko and Igor Fyodorov saw Lunokhod heading toward catastrophe, they could push a button to halt the rover.

Comment on this Story

comments powered by Disqus