2020 may be the year humanity takes its biggest step toward finding evidence of life beyond Earth. NASA and the European Space Agency (ESA) are each working on its own rover that will roam Mars’s surface in search of life.
The ExoMars mission is Europe’s first Mars rover. Named after British DNA pioneer Rosalind Franklin, the golf cart-sized robot is approximately one-third the size of NASA’s planned Mars 2020 rover and will look for signs that life might have existed on Mars.
Both rovers will act as remote scientists, beaming back a wealth of data and images to Earth.
Mars 2020 will collect Martian samples for eventual return to Earth sometime in the future, while ExoMars will use its unique drill to burrow below the surface. Here, the rover will find pristine samples that were shielded from the harsh radiation bombarding Mars’s surface. Scientists are hopeful that below the surface is where we could find our first evidence of life.
A Rover’s Purpose
Mars is a hostile place. Because its atmosphere is much thinner than Earth’s, life as we know it would have a difficult time surviving on the surface.
Billions of years ago, the surface of Mars was probably quite similar to that of Earth. However, that changed when Mars lost its magnetic field, which stripped its atmosphere, and exposed its surface to intense radiation. All of which made survival above ground incredibly challenging.
Historically, Mars missions have searched for signs of life on the planet’s surface, usually at places where there are signs of ancient water. That’s because this is typically where we find life on Earth.
But since we haven’t found life on the planet’s surface yet, mission scientists propose we need to dig deeper. There may be some microbial Martians underground.
The ExoMars rover (and accompanying lander) are a follow-on to ESA’s ExoMars Orbiter mission which reached Mars in 2016. That initial mission consisted of two parts: the Trace Gas Orbiter (TGO) and the Schiaparelli landing demonstrator.
Landing on Mars
TGO made it to Mars and is doing great, however, Schiaparelli didn’t fare so well — the lander crashed during its descent to the Martian surface.
Landing a probe on Mars is not easy. To safely navigate the tenuous Martian atmosphere requires a combination of sophisticated landing gear, including heat shields, retrorockets, and even giant, inflatable airbags.
Despite the crash landing, Schiaparelli achieved its goal as a technology demonstrator. It also showed that the team needed to revamp the landing system before the rover launches. But, with less than a year till liftoff, the rover team is struggling with an established piece of landing architecture: parachutes.
In order to slow the rover down, the mission requires multiple parachutes — one 15 meters (49 feet) in diameter and one 35 meters (115 feet).
As the rover begins its descent, atmospheric drag will slow the craft from around 21 000 km/h (13,048 mph) to 1700 km/h (1,056 mph). That’s when the first parachute will deploy. About 20 seconds later, at about 400 km/h (248 mph), the second chute will deploy. Lastly, the braking engines will kick in about 1 km (or half a mile) above the ground, enabling the rover land safely on the Martian surface.
The entire sequence takes just six minutes.
Parachute Troubles
During high-altitude testing conducted earlier this year, the craft’s parachutes ripped as soon as they deployed. ESA engineers made several adjustments, including reinforcing both the parachutes and their storage bags with Teflon to make them deploy easier. The chutes are still tearing.
Now the agency is turning to NASA for help. ESA engineers are teaming up with the folks at the Jet Propulsion Laboratory, to put the enhanced parachutes through months of rigorous testing.
In the meantime, the rover team is putting its hardware through a round of thermal testing. For 18 days it will be subjected to the same harsh temperature conditions experienced on Mars.
The parachutes are expected to finish testing sometime in April 2020; they will then be integrated with the rover and shipped to the launch site in Kazakhstan. However, if any part of the mission misses its deadline, the entire project could be sidelined until the next favorable Mars launch window — in 2022.
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