50 years ago: Mars 3 taught us to turn failure to success on Mars
Mars 3 accomplished the first soft landing on Mars. Then it died.
There’s really no dressing it up: 1971 was a crummy year for the Soviet Mars program. Of the four robotic spacecraft the USSR sent toward the Red Planet that year, one never made it out of Earth orbit, two were stymied by Martian dust storms, and another crashed into Mars like a speeding bullet.
But the Mars 3 lander had better luck. Somewhat.
Using a sophisticated landing system unmatched until later NASA missions like Pathfinder and Spirit, Mars 3 successfully landed on the Martian surface 50 years ago on December 2, 1971, becoming the first spacecraft to successfully complete a soft landing on another planet. It opened its flower-like shell, turned on its television cameras — and promptly died.
“It only worked, depending on which account you read, for 15 to 20 seconds,” National Air and Space Museum Curator of Planetary Science and Exploration Mathew Shindell tells Inverse. “But the fact that it worked at all is pretty amazing, considering what we know about how difficult it is to land something on Mars.”
Mars 3 was supposed to do more than that though. It had a complete science payload, including the PrOP-M rover, which would have been the first powered vehicle to traverse another planet’s surface by a number of decades. The NASA Sojourner Rover first made tracks on Martian regolith in 1997.
The Americans beat the Soviets in placing the first spacecraft in orbit around another planet with Mariner 9’s November 13 arrival at Mars, but the Soviets could still claim the first successful soft landing — even if the world would have to wait for the NASA’s Viking and later rover missions for the sorts of science Mars 3 would have conducted if it lived.
But it hardly deterred the Soviets, who continued to send spacecraft to both Mars and Venus. While the US and USSR were competitors, their respective planetary scientists all benefited from the science done by their counterparts on each side of the Iron Curtain. “They were as excited about Russian successes as they were about us successes and vice versa,” Shindell says. “Because having two nations spend tons of money on exploring Mars meant you could get potentially twice the science.”
Mars 3 was a pioneering mission, if incomplete, forever a red asterisk on NASA’s Viking missions. Mars 3 was first, but it would take Viking to fulfill the former’s scientific destiny.
A time for competition and cooperation
While Russian and American planetary scientists may have enjoyed the way their joint efforts were advancing their field, there was no doubt that their two countries were very much competitors in the early 1970s. The American Moon landings hadn’t knocked the Soviets out of the space race entirely, not when the space race was still as much about military prowess as it was scientific discovery.
Mars 3 was actually two spacecraft, an orbiter and a lander, both “some of the most robust spacecraft that the Soviet Union had sent out into the Solar System,” Shindell says. Their hefty builds were made possible by the development of a new Proton rocket launch system, a four-stage rocket with the addition of the Blok D upper stage.
The Proton launch system was a product of the Cold War arms race between the US and USSR; Shindell says the Proton-K rocket was originally designed as an intercontinental ballistic missile (ICBM) for launching heavy nuclear warheads. Blok D, meanwhile, was originally developed for the Soviet N1 moon rocket, which would never successfully fly.
Put together, the Proton-K and Blok D could lift nearly 50,000 pounds into orbit, allowing for more hefty planetary missions.
Planetary science missions were another way to demonstrate your ability to hit targets with your missile technologies, but without taking military action. You sub in other worlds for an opponent's cities, scientific payloads for warheads.
“It’s kind of like a gun show,” Shindell says. “There’s definitely an aspect of displaying your military capabilities without, in fact, taking any military action.”
In that sense, sending spacecraft to orbit and land on Mars was a far greater technical challenge than landing on the Moon, and the Soviets wanted to get there first. They knew of NASA’s plans to launch twin Mars orbiters, Mariner 8 and Mariner 9, and hoped to take advantage of the fact that Mariner 8 blew up at launch to beat the US to Mars orbit, according to Shindell.
On May 10, 1971, the Soviets launched M-71S, which was intended to be a Mars orbiter but “got stuck in orbit around Earth because of a programming error in the timing of the upper-stage rocket,” Shindell says. The Soviets renamed the spacecraft Kosmos 419 and designated it as an Earth mission, “So that no one would know that they had failed with that first spacecraft.”
Soviet space innovations
The Soviet hopes came down to Mars 2 and Mars 3, each launched days before Mariner 9 in May of 1971.
They were very different from the hexagonal design of NASA’s Mariner spacecraft, appearing bulbous or like spheres welded together, because that’s essentially what they were: The Soviet electronics required pressurized containers, Shindell says, so their spacecraft were just a series of those containers.
“It's really kind of an elegant design, the Mars 2 and 3 landers,” he says. “The lander itself was kind of an egg-shaped spacecraft with these four petals that opened up after the soft landing was achieved.”
The way the landers were to achieve that soft landing was incredibly innovative and sophisticated for the time, Shindell says.
- The orbiters would release the landers while still traveling toward Mars at full speed
- The landers would use their heat shields to aerobrake, using the friction of the thin Martian atmosphere to convert kinetic energy to heat, slowing the landers to mere supersonic speeds
- Then they would deploy the real innovation — the supersonic parachute
“It's not easy to design a parachute that can work in a very thin atmosphere and at supersonic speeds,” Shindell says. “The Soviets certainly led the way in developing the first version of that.”
Later NASA probes, such as Pathfinder in 1997, would also use aerobraking and supersonic parachutes to land on Mars. But Pathfinder used a giant airbag for its final landing, cushioning the lander until it bounced to a stop.
The Mars 2 and 3 Probes would try something in 1971 that took SpaceX multiple tries to accomplish in the 21st century — landing autonomously using retrorockets. Using the rockets at the end of their descent to accomplish their soft landing, both landers would open their petals and begin taking images.
That was the plan at least.
The failure of M-71S to get out of Earth orbit cost the Soviets more than a shot at achieving the first orbit of Mars. It had been meant to be in orbit prior to the arrival in order to provide the Mars 2 and 3 landers with telemetry data for their high-speed approach to Mars, Shindell says. The landers would have to use an autonomous optical sensor system to correct their course and hit the thin Martian atmosphere at just the right angle to burn off enough speed to safely land.
“Mars 2 over-corrected as it turns out, and put the spacecraft into too steep of an angle of descent into the atmosphere,” Shindell says, and the lander crashed hard into Mars before it could even deploy its parachute. “When it hit the atmosphere, I think it was traveling something like six kilometers a second.”
Mars 3, however, managed to do everything right. It entered the Martian atmosphere at 5.7 kilometers per second, Shindell says, but was able to aerobrake, deploy its parachute, and touch down gently on a cushion of retrorocket thrust. It opened its petals, turned on its cameras, and took a partial, fuzzy grey image before it died, most of the data it collected never making it to the Mars 3 orbiter for transmission to Earth.
Why did Mars 3 fail?
“We don't know exactly why it failed,” Shindell says of the Mars 3 landers. “The best explanation seems to be that because of the planet-wide dust storm and the very thin atmosphere — what may have happened is a short circuit in the electronics.”
The planet-wide dust storm would further frustrate the Soviets by ruining the Mars 2 and 3 orbiter missions. Loaded with film cameras and an unalterable survey program, the orbiters exhausted their film supply on the featureless dust clouds before the global storm abated.
NASA’s Mariner 9, meanwhile, could be remotely reprogrammed and wait out the dust. It would send home the first images of Mars’s most striking geological features including the largest volcano in the Solar System, Olympus Mons.
A legacy of technical persistence
It’s hard not to speculate what the Mars 3 legacy might have been if the lander had survived intact. It carried mass spectrometers, X-ray spectrometers, and gamma-ray detectors. It carried the PrOP-M rover, which would have been the first powered vehicle to traverse the surface of another planet, even if its range would have been limited by a tether connecting it to the Mars 3 lander. The rover would have used innovative skids for locomotion and included a basic obstacle avoidance system.
“[Mars 3] was going to do quite a lot of science there on the surface,” Shindell says, “As well as being the first to do almost everything in terms of planetary science exploration.”
The Mars 3 legacy might best be characterized then as an object lesson in persistence, and a reminder that even within the secretive Soviet space program, there worked individuals of extraordinary intelligence and creativity.
“The Soviet space program was not short on innovation,” Shindell says. “The engineering behind these spacecraft is really impressive.”
The Soviets successfully landed probes on the surface of Venus, a hellish landscape of intense heat and pressure, where they lasted for longer than Mars 3 did on the cold surface of Mars.
Success with missions to the Red Planet remained dicey for the Soviets and the later Russian space program. Mars 4 in 1973 failed to enter Martian orbit. The Mars 7 lander in 1971 missed the planet entirely. The Phobos 1 and 2 probes failed in 1988, and the Russian Phobos-Grunt mission to the Martian moon Phobos failed to leave Earth orbit in 2011. And on October 16, 2016, the Schiaparelli Mars lander technology demonstrator Russia built with the European Space Agency crashed into the Red Planet rather than making the intended soft landing.
But the missions have never stopped. Roscosmos, the Russian space agency, has been working with the European Space Agency to develop a new Mars mission, the Rosalind Franklin rover, which is expected to launch in September 2022.
“Maybe that’s part of that [Mars 3] legacy that is very Russian,” Shindell says. “Despite failure, that doesn’t mean you should stop trying.”