It traversed craters, snapped photos of hard-to-reach regions on the ground, and served as a surprisingly resilient scout who adapted to the changing Martian atmosphere and survived its harsh dust storms and storms. freezing nights.
Now engineers and scientists at NASA’s Jet Propulsion Laboratory fear their four-pound Mars solar-powered drone is nearing the end of its life.
Winter is coming to Mars. Dust kicks up, covering Ingenuity’s solar panels and preventing it from fully charging its six lithium-ion batteries. This month, for the first time since landing on Mars more than a year ago, Ingenuity missed a scheduled communications session with Perseverance, the Mars rover it relies on to send data and receive messages. Earth commands.
What’s up with Percy the Mars rover?
Will a dust-covered Ingenuity survive a Martian winter where temperatures regularly dip below minus 100 degrees Fahrenheit? And if not, how should the world remember the tiny helicopter that cost $80 million to develop and over five years to design and build? Those closest to the project say that as time goes by for Ingenuity, it’s hard to overstate its accomplishments.
“The helicopter just far exceeded those initial expectations,” Lori Glaze, director of NASA’s Planetary Science Division, told The Washington Post.
Given the thin Martian atmosphere, the scientists and engineers who worked on the Ingenuity weren’t at all sure that the experiment would succeed. Thomas Zurbuchen, the associate administrator of NASA’s Science Mission Directorate, said at the time that it was an undertaking that forced NASA to find the “good line between crazy and innovative”.
So when the first flight, on April 19, 2021, was a success, NASA heralded it as a Wright Brothers moment. As a tribute, Ingenuity had a mail-size piece of fabric from the brothers’ plane, known as the Flyer, attached to a cable under the solar panel.
Ingenuity soared to Mars strapped to the belly of the Perseverance Rover, the star of NASA’s most recent mission to Mars. After traveling some 300 million miles in seven months, Perseverance landed in a spectacular landing in February 2021 under a parachute with a secret code slipped inside that read “Dare Mighty Things”.
The SUV-sized rover landed in an area of Mars known as the Jezero Crater, which once held water and could provide clues to the planet’s history and existence. of life there. The rover collects rocks and soil samples that NASA hopes to bring back to Earth on a future mission, and uses its seven instruments to conduct science experiments and test new technologies.
The ingenuity was something of an add-on, a technological demonstration that could prove useful for future missions and allow space agency scientists to explore more of the Martian landscape than they could on land alone.
But flying an autonomous drone on Mars would be extremely difficult. The atmosphere there is only 1% the density of Earth’s, so to generate lift, the helicopter’s four-foot-wide blades would have to spin incredibly fast – 2,500 rotations per minute.
“We built it as an experiment,” Glaze said. “So it didn’t necessarily have the flight-qualified parts that we use on big missions like Perseverance.” Some, such as smartphone components, were even commercially purchased, so there were chances that they might not perform in the environment as we expected. And so there was a risk that it would not go well.
As Ingenuity continued to fly, ground controllers began to realize that their little project could accomplish big things. Before its fifth flight, they wrote in a blog post that “our helicopter is even more robust than we had hoped. The power system we’ve been worrying about for years provides more than enough power to run our heaters at night and fly during the day. The off-the-shelf components of our guidance and navigation systems also work very well, as does our rotor system. You name it, and it’s just fine or better. »
As it continued to operate, NASA scientists became increasingly intrigued by the idea that perhaps this helicopter could become an integral part of the mission.
“What happened, and that’s really key, after Ingenuity performed so well in those first five flights, the Perseverance science team came to us and said, ‘You know what? , we want this helicopter to continue to operate to help us in our exploration and to achieve our science goals,” Glaze said.
NASA therefore decided to continue flying.
On her sixth flight, Ingenuity ran into trouble. The helicopter navigates with a camera that takes 30 frames per second of the terrain below, each with a timestamp. An algorithm predicts what the camera should have seen at that exact moment based on images taken moments before. Then it calculates the difference between the predicted location and the actual location of ground features to correct its position, speed and altitude.
But on this flight, the timestamps were off. As a result, Ingenuity appeared to be flown by a drunk driver, “adjusting its speed and tilting back and forth in an oscillating pattern,” NASA said in the blog post.
Still, he was able to land safely within 16 feet of his target thanks to “extensive efforts made to ensure that the helicopter’s flight control system has sufficient ‘margin of stability’,” wrote The NASA. In other words: “In a very real sense, ingenuity coped with the situation.”
Flight 9, in July, was also a “nail biter”, as NASA wrote. Not just because Ingenuity broke flight time and cruise speed records, but because it flew over a crater, “an area called ‘Séítah’ that would be difficult to traverse with a land vehicle like the Perseverance rover. “, NASA wrote in its blog.
Because Ingenuity was designed as an experimental technology demonstration, engineers designed it to fly over largely flat terrain, more easily navigated by its on-board camera. For this flight, however, Ingenuity would have to dive into the crater. This forced him to reduce his speed and the engineers to change the navigation algorithm. The flight was a success, and Ingenuity was able to return colorful photos of the area, including a location that some say “could record some of the deepest aquatic environments of ancient Lake Jezero,” NASA wrote. . “Given the tight mission schedule, they may not be able to visit these rocks with the rover, so Ingenuity may provide the only opportunity to study these deposits in detail.”
Since then, Ingenuity has persevered, overcoming obstacle after obstacle. Sometime in September he detected an engine problem during his pre-flight check “and did exactly what he was supposed to do: he canceled the flight”.
About a month later the problem was resolved and he resumed flying.
In April, he made another discovery – while flying over the parachute that slowed the rover for its landing on Mars, he spotted the ruins of the shell that had protected the rover as it plunged toward the Martian surface. There were a pair of man-made objects sitting on another planet, images that “just blew your mind,” Glaze said. In the past, NASA was able to spot vehicles on the surface of Mars thanks to a spacecraft in deep orbit. But there were pieces of hardware here, close-up, in such high definition that the “Dare-Mighty-Things” encoded in the chute were visible through a thin layer of red Martian dust.
Then, 10 days later, on April 29, he made his final flight, No. 28, a quarter-mile jaunt that lasted two and a half minutes. Now NASA wonders if it will be the last.
The space agency believes the helicopter’s inability to fully charge its batteries caused the helicopter to enter a low-power state. When it became inactive, the helicopter’s on-board clock reset, as household clocks do after a power outage. So the next day, as the sun rose and began to charge the batteries, the helicopter was out of sync with the rover: “Essentially, when Ingenuity thought it was time to contact Perseverance, the base station rover wasn’t listening,” NASA wrote. .
Then NASA did something extraordinary: Mission controllers ordered Perseverance to spend almost all of May 5 listening to the helicopter.
Finally, little Ingenuity phoned home.
The radio link, according to NASA, “was stable”, the helicopter was in good condition and the battery was charging at 41%.
But, as NASA warned, “one radio communication session does not mean Ingenuity is out of the woods. Increasing (light-reducing) dust in the air means charging the batteries of the “Helicopter at a level that would allow important components (like the clock and heaters) to stay powered up all night presents a significant challenge.”
Maybe Ingenuity will fly again. Maybe not.
“At this point, I can’t tell you what’s going to happen next,” Glaze said. “We are still working on trying to find a way to get it flying again. But perseverance is the main mission, so we have to start setting our expectations appropriately. »