NASA’s Perseverance rover is about to begin searching for life on Mars


Landing

The technical terms for the Seven Minutes of Terror are “entry, descent and landing” or EDL. It begins when the spacecraft enters the upper Martian atmosphere at around 20,000 kilometers per hour (12,500 miles per hour) and faces rapidly rising temperatures. Perseverance is protected by a heat shield and shell, as well as a suite of 28 sensors that monitor hot gases and winds. Temperatures peak at 13.00 ° C (2400 ° F).

About four minutes after the start of the EDL – about 11 kilometers (seven miles) above the surface and still on the ground at about 1,500 km / h (940 mph) – the rover deploys a 21-meter parachute. space will get rid of its heat shield soon. Underneath are a host of other radar and camera instruments that will be used to place the spacecraft in a safe location. Software called Terrain-Relative Navigation processes the images taken by the cameras and compares them to an onboard topographic map to determine where the spacecraft is located and what potential safety points it needs to head to.

Just under six minutes after the start of the EDL and about two kilometers in the air, the outer shell and parachute separate from the rover and Perseverance heads straight for the ground. The descent stage (attached to the top of the rover) uses its thrusters to find a safe spot within 10 to 100 meters of its current drop location, and slows down to around 2.7 km / h (1.7 mph ). Nylon cords on the descent stage lower the rover to the ground a distance of 20 meters (66 feet) into the air. Once the rover hits the ground, the cords are cut and the descent stage flies off to crash into the ground at a safe distance. Perseverance is now in his new home.

A view of the Jezero crater. On the left, a spectral map of mineral deposits shaped by water activity in the past. To the right is a hazard map created to illustrate high rugged terrain that Perservance will seek to avoid when landing.

NASA

Science

Spirit and opportunity have helped us better understand the history of water on Mars and curiosity found evidence of corganic complex—Carbon-rich molecules which are the raw materials of life. Together, this evidence told us that Mars may have been habitable in the past. Perseverance will take the next important step:looking for signs of ancient alien life.

Why the Jezero crater? It is a 3.8 billion year old lake bed. A river carried water there, and it was in the river delta that the sediments could have deposited preserved organic compounds and minerals associated with biological life.

Twenty-three cameras on Perseverance will study Mars for evidence of life. The most important of these is the Mastcam-Z camera, which can take stereoscopic and panoramic images and has an extraordinarily high zoom capability to highlight targets (such as soil models and ancient sediment formations) which deserve further study; SuperCam, which can study the chemical and mineral composition of the rock and has a microphone that will be used to listen to the Martian weather; and the PIXL and SHERLOC spectrometers, which will search for complex molecules indicating biology. SHERLOC’s Watson camera will also perform microscopic images up to a resolution of 100 microns (barely larger than the width of a human hair).

Briony Horgan, a planetary scientist at Purdue University who is part of the Mastcam-Z team, says scientists are more interested in finding organic matter that is highly concentrated or could only be the result of activity. biological, like stromatolites (fossilized remains created by layers of bacteria). “If we find particular patterns, it could be called biosignature, proof of life,” she says. “Even if it’s not focused, if we see it in the right context, it could be a really powerful sign of a true biosignature.”

After Perseverance arrives, engineers will spend several weeks testing and calibrating all instruments and functions before scientific investigation begins in earnest. Once this is complete, Perseverance will spend a few more months visiting the first exploration sites at Jezero Crater. We could find evidence of life on Mars as early as this summer – if it was ever there.

New world, new technology

Like any new NASA mission, Perseverance is also a platform for demonstrating some of the solar system’s most advanced technologies.

One is MOXIE, a small device that seeks to transform the heavy Martian atmosphere from carbon dioxide into usable oxygen through electrolysis (using an electric current to separate the elements). It’s been done on Earth before, but it’s important to prove it works on Mars if we’re hoping humans will ever be able to live there. The production of oxygen could not only provide a Martian colony with breathable air; it could also be used to generate liquid oxygen for rocket fuel. MOXIE should have about 10 opportunities to produce oxygen during the first two years of Perseverance, at different seasons and times of the day. It will run for about an hour each time, producing 6-10 grams of oxygen per session.

There’s also Ingenuity, a 1.8-kilogram helicopter that could perform the first powered controlled flight ever to another planet. The deployment of Ingenuity (which is stored under the rover) will take approximately 10 days. Its first flight will be about three meters in the air, where it will hover for about 20 seconds. If it manages to fly in Mars’ ultra-thin atmosphere (1% as dense as Earth), Ingenuity will have a much better chance of flying elsewhere. Two cameras on the helicopter will help us see exactly what it sees. Ingenuity alone won’t be essential to exploring Mars, but its success could pave the way for engineers to think of new ways to explore other planets when a rover or lander won’t suffice. .

None of these events will be the highlight of Perseverance. The highlight of the mission, which can take 10 years to complete, will be the return of samples of Martian soil to Earth. Perseverance will drill into the ground and collect more than 40 samples, most of which will be returned to Earth as part of a joint NASA-ESA mission. NASA officials suggest this mission could take place in 2026 or 2028, meaning the earliest possible for their return to Earth is 2031.

Collecting such samples is no easy task. Robotics company Maxar built the Sample Handling Arm (SHA) that controls the drilling mechanism to collect the Martian soil cores from the ground. The company had to build something that operated on its own, with hardware and electronic components capable of withstanding temperature variations from -73 ° C (100 ° F) at night to over 20 ° C (70 ° F). F) during the day. And most importantly, he had to build something that could cope with Martian dust.

“When you talk about a moving mechanism that has to apply force and go exactly where you need it, you can’t have a tiny particle of dust that stops the whole show,” says Lucy Condakchian, CEO of the robotics at Maxar. SHA, located under the rover itself, is exposed to a ton of dust raised by the rover’s wheels or by drilling. Various innovations should help it resist this problem, including new lubricants and a metal accordion design for its lateral (back and forth) movement.

However, before any of these things work, the rover has to get to Mars in one piece.

“He never gets old,” says Condakchian. “I’m just as nervous as on previous missions. But that’s a good nervousness – an excitement to start over.

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