Into the great unknown: ExoMars 2020 and the hunt for Martian life
From Fukushima to the darkest corners of the ocean, robots built for extreme environments and an appetite for discovery continue to enlighten our understanding of places too dangerous to tread. Those launched into deep space may be the most daring examples, continually pushing the limits of human ingenuity and expanding our understanding of the universe. In this series New Atlas will be profiling space probes, both past and present, tasked with pushing the boundaries of science by leading us into the great unknown. This week we cast an eye to the future and a mission that hopes to uncover signs of life on the Red Planet: ExoMars 2020.
Name: ExoMars 2020
Launch: August 2020
Subject of study: Mars and its potential for life
Current location: Under development at ESA
Has life ever existed on Mars in its 4.6-billion-year history? Humankind has sent more than a dozen spacecraft to investigate our planetary neighbor, with some built to dig into the surface and others to roam its dusty terrain. The ExoMars 2020 mission will be the first to do both when it launches next year, using its drill and suite of instruments to sniff out organic material that could reveal past or even present life.
The ExoMars 2020 mission is a part of the European Space Agency and Roscosmos’ wider ExoMars program, which encompasses two separate missions to the Mars. The first of those took off in 2016, placing a Trace Gas Orbiter in circulation around the Red Planet and deploying the Schiaparelli lander toward the surface.
The Trace Gas Orbiter component continues to orbit Mars and examine its atmosphere for trace gases like methane and water vapor, though the lander crashed and exploded during its touch-down attempt. This prompted an extensive investigation that would inform the design and procedures for take two, the ESA/Roscosmos ExoMars 2020 mission.
All going to plan, the mission will place a European rover and a Russian science platform on the surface of Mars. These will travel to the planet within the one carrier module after being shot into space by a Russian Proton rocket, before a descent module carries them safely to the surface using parachutes and thrusters to slow down the descent.
With 145 million square kilometers of Mars surface area to choose from, mission scientists had plenty of options in determining the landing site for the ExoMars 2020 rover, but the process was far more involved than simply picking a random spot on a map.
There is a lot to consider in trying to give a mission like this the best chance of success. To maximize the scientific return on their investment, ESA and the Russian agency were after a geologically diverse site with strong evidence of past water and ancient material, meaning material older than 3.6 billion years. And to avoid another crash landing, the descent module will require as much atmosphere as possible to reduce its speed, meaning the site must rest in a low-lying part of the Martian terrain.
Over a process lasting around five years, the team recently settled on a location known as the Oxia Planum. This flattened area near the equator was deemed the best destination for the Russian-built science platform and the rover, which earlier in the year was named after scientist Rosalind Franklin, whose work was key in unraveling the double helix structure of our DNA.
Oxia Planum sits around 3,000 m (1.8 mi) below what scientists consider “sea level” on Mars and offers one of the richest clay deposits we know of on the Red Planet, which orbital observations have shown were formed in wet conditions around four billion years ago. What’s more, it lies at a point where lots of channels join up to empty materials into the lowland area, some of which has been recently exposed through erosion.
Though the landing has been carefully planned, there is still an amount of uncertainty owing to the unknown atmospheric conditions the descent module will encounter on the way down. This means it could settle on Mars anywhere within an ellipse-shaped landing zone measuring 120 x 19 km (75 x 11 mi).
Following touch down, the Russian-built science platform will stay put and study the surface environment at the landing point. Onboard will be radio science experiments, pressure and humidity sensors, radiation and dust sensors, magnetometers, spectrometers, seismometers and a set of cameras. These instruments will be used to image the landing site and study subsurface water distribution, the planet’s atmosphere, and its internal structure.
The ExoMars 2020 rover, meanwhile, will be capable of traveling kilometers away as it hunts for signs of life. It will be able to drill two meters (6.6 ft) into the surface of Mars, in the hope that the underground samples it retrieves will contain better preserved biomarkers. This is because the buried samples will be better protected from the space radiation, with Mars’ very thin atmosphere doing little to safeguard exposed material at the surface.
There will be scant opportunity to communicate with the six-wheeled rover once it scoots away from the science platform, with mission control only able to send commands once or twice each Martian day. This means it will carry out a lot of its operations autonomously, using stereo cameras to build digital navigation maps and collision avoidance cameras to find its way safely across the terrain.
Scientists on Earth will use these images to set target destinations for the rover, before leaving it to do its thing. Once it has extracted samples of subsurface material, the drilling elements will pass it off to an onboard laboratory where it will be crushed into a fine powder for chemical, physical and spectral analysis.
The ExoMars 2020 mission is expected to launch next July or August for a nine-month journey to Mars, but things haven’t been going to plan of late. Back in May, one of the main parachutes that will be used to lower the descent module to the surface suffered damage during testing. Alterations to the design followed, but the next round of testing in August produced similar results. The team is now going over the data from these tests ahead of another high-altitude test in the coming months, though how these setbacks affect the launch schedule is currently unclear.
When it does set sail, the ExoMars 2020 spacecraft will be just one of several to make for Mars in the coming years. Also slated for launch sometime in mid-2020 is NASA’s Mars 2020 rover and China’s Mars 2020 mission, while SpaceX, has plans of its own that could extend beyond sending a robot to the surface. Even if all of these missions aren’t entirely successful, we stand to learn a whole lot more about the Red Planet in the coming decade.
Thus concludes our “Into the great unknown” series. To check out the other seven installments, click here.
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