But there was compensation. After one particularly grueling session, Basilevsky emerged from the control center to see the moon hanging above the horizon in the early morning sky. It was a magically disorienting sight. “When you are involved in driving, psychologically you are on the moon,” he explains. “So [when I saw the moon] it was like, ‘Okay, but I was there!’ And it was some special moment in my life when I realized that through these devices, I was there. On that shining object in the sky.”
In the United States, that bright, cratered world had become a place for men, not machines, to explore. As it happened, the Soviet robotic successes came as NASA was recovering from the previous April’s Apollo 13 fiasco. At the same time, U.S. space budgets were in decline, forcing the cancellation of the last few Apollo landings. The Soviet robots’ success fueled a debate in the U.S. on whether sending people to the moon was worth the cost and the risk when machines could do the job—or so critics claimed. That point of view never held any sway with the scientists. Apollo 11 and 12 lunar sample co-investigator Bevan French recounts: “Anyone who…said that the Luna 16 and Lunokhod missions were so successful that it meant we should have stopped doing manned lunar missions would’ve been laughed out of the room.”
No one needed to tell Basilevsky that. “It was obvious that the science we were doing [with Lunokhod] was much less important than what was obtained by Apollo,” he says. But to the Soviet people, the value of the Lunokhod and Luna robots had little to do with absolutes. In the USSR, where information about the Apollo landings was scarce, these machines were a source of enormous pride. Soviet scientists could now contribute lunar samples for research instead of merely borrowing; in 1971 NASA and the Soviet Academy of Sciences agreed to each exchange three grams of returned samples.
In January 1973, a month after Apollo 17, the final U.S. moonwalk, Lunokhod 2 landed at the Sea of Serenity’s eastern edge. By this time, the stature of Basilevsky and the other geologists had risen substantially—as had the confidence of the two crews—so much so that after four months on the moon Lunokhod 2 had driven more than 21 miles, three times as far as Lunokhod 1 had traveled in twice the time. (It helped that Lunokhod 2’s navigation cameras were improved, and sent an image every three seconds.) Near the end of its fourth lunar day, the rover approached a long, straight valley where the geologists could see boulders and even the rarest of features on the dust-covered moon: an outcropping of bedrock. Basilevsky was ecstatic. “He kept exclaiming, ‘Wonderful, this is it! Stop, look at this, show me that!’ ” says Dovgan.
Then, on May 9, 1973, the crew made a fatal mistake. “The sun was behind us,” Basilevsky says. “In the navigation camera we saw a beautiful smooth surface.” But the pictures were deceiving. All shadows were hidden behind the objects casting them—including crater walls. Before anyone realized what had happened, Lunokhod descended into a crater some 15 feet across. What the crew should have done, Basilevsky says, was to stop, close the rover’s lid, then take a panorama to see where they were; instead, the controllers started maneuvering Lunokhod out of the crater. The lid touched the crater wall, resulting in part of the solar cells being covered with soil. “We immediately felt it, because the electric current dropped,” Basilevsky says. Within an hour of entering the crater, Lunokhod had re-emerged, and all seemed well—until everyone realized what would happen as night approached. The rover’s lid would have to be closed to keep it from freezing during the night. When the team closed the lid, they dumped lunar grime on the radiator, which was supposed to get rid of excess heat during the day. “We put on this radiator the best insulator—lunar soil,” Basilevsky laments.
With the arrival of a new day, the lid was opened, and soon afterward, as the rover began its work, sensors showed the temperature aboard Lunokhod 2 increasing. Everyone knew it was only a matter of time before the rover would die. Before that happened, Basilevsky realized, Lunokhod could make a risky but potentially rewarding venture to some nearby, geologically intriguing mountains. He told the controllers, “Go to that place; we will die like heroes. If we just go stupidly in some safe direction, we will die anyway.” But mission managers were unwilling to risk it, and once the temperatures aboard Lunokhod climbed above 150 degrees Fahrenheit, Basilevsky says, “That was the end.”
A third Lunokhod was planned, and there was talk of a mission more ambitious and potentially much more rewarding than Lunokhod. Named Sparka, from the Russian word for “pair,” the mission would team a Lunokhod-style rover with a Luna sample-return craft. Roaming the moon, the Sparka rover would pick up samples with a robotic arm, take pictures, and carry its geologic treasures to a waiting sample-return vehicle. With a well-chosen, well-documented collection of samples, Sparka promised a scientific return equalling that of the Apollo landings.
It was not to be. Support for more robotic missions to the moon evaporated as interest shifted to a more distant and mysterious goal: Mars. Already, the Soviets had tried two times to land instruments on the Red Planet without success, and it was public knowledge that the United States was planning its own Mars landings, in a program called Viking. Lunokhod 3 never went to the moon—the rover now sits on display at the Lavochkin Museum in Moscow—and Sparka never made it past the conceptual stage. Meanwhile, the giant N-1 booster, designed to put humans on the lunar surface, had exploded in four separate test launches, effectively dooming any hope of a Soviet manned landing.
Like so much about the Soviet space program, many details about the robotic lunar missions remained secret for decades. Lunokhod’s crews were not publicly acknowledged for their work until 1990, and today, Lunokhod’s forgotten images seem like postcards from a parallel history just coming to light. Basilevsky and his colleagues had a bittersweet flash of recognition in 1997, when NASA’s Pathfinder Lander delivered a diminutive rover called Sojourner to Mars. Although Sojourner did most of its exploring within about 35 feet of its lander, Dovgan and his fellow controllers were so impressed that they wrote a letter of admiration to NASA (which, according to Dovgan, the agency did not answer).
Among the creators of Pathfinder and Sojourner, the reviews of Lunokhod are mixed. According to Don Bickler of NASA’s Jet Propulsion Laboratory in Pasadena, California, one of the engineers who directed Sojourner’s design, technology has changed so much since the early 1970s that the Mars rover bore little resemblance to its lunar predecessor. Bickler says that during his work on Sojourner he briefly studied the Lunokhod design, but he wasn’t influenced by it. “There was nothing we could use there,” he says flatly.
Down the hall from Bickler, Tom Rivellini offers a kinder perspective. Rivellini, who helped create the airbags that got Pathfinder and Sojourner safely to the Martian surface, is now working on a proposed robotic mission to retrieve samples from the moon’s south polar region. He says of the Soviet missions, “When you go back and look at this stuff, it’s impressive…. They were inventing the wheel; nobody had done this.” Rivellini points out that unlike the Soviets, whose big Proton boosters could carry heavy payloads, he and his colleagues have to design for smaller launchers, a limitation that can make spacecraft design and production more difficult and expensive. Still, Rivellini says, future robotic explorers that roam the planets will owe a debt to Lunokhod. “Personally, the way I view the work the Soviets did back in those days is as a proof of concept that it could be done,” Rivellini says.