Return to the Red Planet

Our latest envoy to its close neighbor carries the torch of human ingenuity.

Return to the Red Planet

Eight years and 213 Earth-days into Curiosity’s journey, NASA has recruited a new ambassador to venture to Mars. Building on revolutionary advancements in aerospace technology, the Perseverance Rover has inherited the legacy of its predecessor, carrying the torch of human inquiry as we continue to explore the solar system.

Launched on July 30th, 2020, the Perseverance Rover is the fifth rover to have successfully landed on the Martian surface. Like Curiosity, its primary mission is to analyze rock and soil to search for evidence that, at some point in the distant past, life may have existed on Mars.

As theorized by chemists, geologists, and physicists alike, Mars was a habitable planet in its youth, similar in surface conditions to Earth. Around 3.8 billion years ago, Mars is predicted to have had a liquid mantle, which, due to convection currents within the planet, may be the root cause of volcanic activity in Mars’ distant past. With the presence of volcanism came the accumulation of gases into a stable atmosphere, and subsequently a liquid water ocean -- the evidence for which can be seen in water ice deposits in and above the planet’s surface. Though the Curiosity Rover helped to establish these theories, its successor will go another step further.

Using a menagerie of sensors and other instruments, the Perseverance rover will examine and collect samples of Mars’ iron-rich regolith -- that is, a portion of the Martian surface composed of rock and soil-like dust. Our moon has a similar regolith, but it is primarily composed of feldspar and other minerals, whereas Mars’ regolith contains far more iron oxides and perchlorate salts. Though previous missions have uncovered vast lake beds and canals, as well as troves of water ice embedded in the Martian regolith, only Curiosity has examined these environments up close. In the process, we have learned that chemical deposits in the beds themselves are indicative of aqueous activity in the distant past, leading to theories that the high salt content of Mars’ soil may provide clues towards a liquid subsurface ocean -- though the evidence for this is next to none. With powerful tools designed to pick apart and dissect the surface of the red planet, Perseverance will continue this research, its synthetic camera eyes trained on the open-ended questions Curiosity left behind, using more advanced techniques to scan for biosignatures that would imply that life could, at some point, exist there.

An image of a Martian lake taken by Curiosity, revealing deposits of metallic and carbonaceous materials, among isotopes such as deuterium (a form of hydrogen whose nucleus is composed of a single proton-neutron pair).

To actually land on Mars, the Perseverance rover used a similar technique to Curiosity, employing the technology of the sky crane. In short, this device consists of an octet of rocket thrusters attached to a large lander-like module, within which the rover is safely contained. Upon reaching a low enough altitude, the rover will lower from the craft by way of a series of tethers. Once safely on the ground, the tethers will be cut, as the sky crane careens out of sight to crash at a far-off spot. Left behind is the rover, free to begin its mission. Being the second rover to use sky crane technology, Perseverance was also the first to capture a detailed video recording of the descent. Though Curiosity had provided footage of its landing in 2012, Perseverance was the first to be seen in its full glory by way of cameras aboard the sky crane and the rover itself.

A diagram of the Curiosity landing in 2012, utilizing the novel sky crane mechanism.

Though the Perseverance rover is astounding on its own, it isn’t alone on its mission. Nestled aboard is a small, helicopter-like aviator dubbed “Ingenuity.” Being the first-ever aircraft to traverse the Martian atmosphere, Ingenuity is designed as a proof-of-concept for aerial travel in Mars’ thin atmosphere. Once Perseverance travels to a safe destination, Ingenuity will conduct a routine series of flights to predetermined locations, returning to the rover each time. With each new flight, Ingenuity will travel farther from its crewmember, pushing itself to the very limit of its capacity for flight. With a small array of solar panels attached to the craft, Ingenuity will be able to sustain flight for longer periods of time than if it were to run on other forms of fuel, such as chemical or nuclear.

A digital model of the Ingenuity aircraft, complete with its dual-rotor propeller and solar panel.

Though less important than its central goal, Perseverance is the very first interplanetary rover to prepare for human contact -- a milestone in technology the world may very well be ready for in the next several decades. By extracting and compressing carbon dioxide molecules from the Martian atmosphere, the rover will split the gas into its constituent elements -- carbon and oxygen. With this technique, the rover will be a proof-of-concept for how future missions might provide resources for human habitation. Even if Mars’ atmosphere is only 1% as dense as our own, the ability to produce oxygen gas would be an achievement that could follow humanity into the far future of space exploration, using new methods like the Sabatier reaction and electrolysis to produce water and oxygen from worlds beyond our own.

A stoichiometric representation of the Sabatier reaction, a method by which we might begin to colonize the Red Planet.

The Perseverance mission is by far the most daunting in human history -- but if it goes as planned, the future of space exploration will be brighter than ever before.