The First Mars Rover

Jul 26, 2021 3 comments

In May 1971, the Soviet Union sent to Mars two robotic space probes launched within nine days of each other—Mars 2 and Mars 3. Neither space probes completed its mission. Mars 2 crash-landed on the planet and Mars 3 ceased transmissions less than two minutes after landing. Despite the failed mission, Mars 3 did achieve its one primary objective: it became the first space craft to make soft landing on Mars, carrying what would have been the first ever Mars rover.

1972 Soviet stamp commemorating the Mars 2 and Mars 3 missions

A 1972 Soviet stamp commemorating the Mars 2 and Mars 3 missions. Photo: Wikimedia Commons

Both Mars 2 and Mars 3 consisted of identical spacecraft with identical hardware. They also had identical mission objectives, which was to make soft landing on the Red Planet and take photographs of the Maritain landscape, study the topography, composition and physical properties of the surface, measure properties of the atmosphere, monitor the solar wind and the interplanetary and Martian magnetic fields, and act as a communications relay to send signals from the landers to the Earth.

Just two weeks prior to the launch of Mars 2 and Mars 3, the planet’s surface was chopped up by a fierce dust storm that threatened to sabotage the upcoming launches. Because it was too late to reprogram the mission computers, it was decided that the launches would go ahead as scheduled, but instead of imagining the surface of Mars, a significant portion of available data resources was allocated to snapping images of the dust storm from the orbiter.

Mars 2 was launched on 19 May 1971 from Baikonur Cosmodrome. It reached Mars’s orbit on 27 November 1971. Just prior to orbit insertion, a spherical descent module detached from the orbiter and shot towards the Martian surface. But the angle of entry was too steep and the descent system malfunctioned. The parachute failed to deploy and the capsule crashed violently into the planet, possibly disintegrating into a million pieces. It was the first man-made object to reach Mars.

Mars 2/Mars 3 orbiter.

Mars 2/Mars 3 orbiter.

Mars 3 Lander model at the Memorial Museum of Cosmonautics in Russia.

Mars 3 Lander model at the Memorial Museum of Cosmonautics in Russia.

Mars 3 was launched on 28 May 1971, and reached the planet’s orbit on 2 December 1971. The orbiter suffered from a partial loss of fuel and did not have enough to put itself into a planned 25-hour orbit. The engine instead performed a truncated burn to put the spacecraft into a highly-elliptical long-period orbit about Mars. In any case, the insertion was a success.

About four hours prior to orbit insertion, the descent module separated from the orbiter, and the descent engine was fired to take the module towards the Martian surface. The module entered the thin atmosphere at a shallow angle, allowing the aeroshields to achieve maximum aerobraking. When the speed had reduced significantly, the braking parachute was deployed, followed by the main chute that brought the craft below supersonic velocity. At this point the heat shields were ejected. At an altitude of 20 to 30 meters when velocity was still 60 to 110 m/s the main parachute was disconnected and retrorockets were fired, which kept on firing until the craft touched down gently on the Martian surface. It was the first soft landing on the planet, and a massive achievement for Soviet scientists.

Without wasting any time, the lander shed its petal-like covers and began preparation for the rover to be deployed.

PROP-M Mars rover.

PROP-M Mars rover.

The rover called PROP-M was a small, squat box, less than a foot on each side, and tethered to the lander by an umbilical cable just 15 meters long. Evidently, the rover was not designed for extensive exploration. Instead of wheels, the rover was equipped with skis and it was supposed to “walk” upon these. As radio signals from Earth would take too long to drive the rovers using remote control, the rover carried its own obstacle detection systems. The rover also carried a dynamic penetrometer and a gamma ray densitometer to measure the bearing strength and density of the soil.

The lander began transmitting 90 seconds after landing, but after 20 second of transmission, the lander went silent. The cause of the failure was never determined, but it could have been the fierce Maritain storm taking place at the time which may have induced a coronal discharge, damaging the communications system. During its brief transmission, the lander sent a partial, grainy image that was hard to identify. It could have been the Martian surface, or the blowing dust storm, or simply radio noise. This image was not revealed to the public until the 1980s, when Soviet leader Mikhail Gorbachev encouraged increased scientific cooperation with the West.

The only image transmitted by the Mars 3 lander before it went silent.

The only image transmitted by the Mars 3 lander before it went silent.

“One of the features that I've noticed about the Soviet space program was that, first of all, if they didn't think a photograph was good enough, they didn't release it,” said Irish writer Brian Harvey.

“So it wasn't a question of it being secret; they just felt that it didn't tell you enough, give you enough detail. So, they took the decision for us -- wrongly in my view -- that they should just not release it. They wanted something that could show something very definite very quickly,” Harvey explained.

Decades later, while recounting the hectic days and Soviet bureaucratic urgency surrounding the Mars missions, V.G. Perminov, the leading designer for Mars and Venus spacecrafts, wrote: ”the United States had put humans on the Moon, and the Soviet Union had put a cosmonaut in space and circled the Moon with a satellite. However, sending a spacecraft to a distant planet and having it enter an unknown atmosphere and land on a poorly known surface was an undertaking of a different magnitude."

Five years later, the Viking Lander 1 sent the first clear photograph of the surface of Mars after successfully landing on the planet in July 1976.

first clear photograph of the surface of Mars taken by the Viking Lander 1

The first clear photograph of the surface of Mars taken by the Viking Lander 1

Far above the raging dust storm, the orbiters of Mars 2 and Mars 3 fared better than its ground companions. They continued to orbit the planet for months snapping up images and providing other useful data that would contribute greatly to knowledge of planet. For instance, the images and data revealed mountains as high as 22 km, atomic hydrogen and oxygen in the upper atmosphere. The orbiters measured the surface temperature, atmospheric pressures, water vapor concentrations, and the height of the ionosphere. The images and data these twin probes gathered enabled creation of the planet’s surface relief maps, and gave information on the Martian gravity and magnetic fields.

It would take another 26 years before NASA finally put a rover on Mars—the Sojourner rover aboard the Mars Pathfinder spacecraft. It operated for 85 days before its battery failed.

# Andy Heil, The Soviet Mars Shot That Almost Everyone Forgot, RFERL
# V.G Perminov, The Difficult Road to Mars


  1. And look at what the Americans are doing on Mars now !

    1. Mostly exploding tens of billions of dollars in wealth and prosperity, money which could accomplish much more on this planet.

    2. I agree. Money should be spent to improve the human problems on earth.


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