NASA’s Mars InSight lander slowly died of dust last week. For months and months, the robot, built to study tectonic activity on the Red Planet, ran on less and less power as its 25-square-foot (4.2-square-meter) solar array gradually disappeared under a thick blanket of dust. . On Wednesday, Dec. 21, NASA announced that it hadn’t heard from the lander in days, officially declaring the mission dead.
Insightwhich landed in the flat and seemingly uninspiring basin of Elysium PlanitiaSouth of Marchequator in November 2018, exceeded the planned duration of its mission by two years. Still, many have asked if anything could have been done to save the otherwise perfectly healthy robot, which had provided groundbreaking science on the internal life of mars.
Cost versus benefit
In one Twitter feed (opens in a new tab)Released about six weeks before InSight’s ultimate demise, NASA explained the trade-offs engineers face when designing a mission to notoriously dusty Mars.
“People often ask: don’t I have a way to dust myself off (windshield wiper, blower, etc.)? That’s a good question, and the short answer is this,” NASA wrote on the Lander’s Twitter account. “A system like that would have increased cost, mass and complexity. The easiest and most cost effective way to achieve my goals was to bring in solar panels large enough to power my entire mission – which they did (and more!).”
Dust storm season
When sending landers to Mars, space agencies usually try to avoid dust storm season, which occurs during the autumn and winter periods of northern Mars. For a year on Mars lasts about two Earth years, most recent landers and rovers, including InSight, have been through multiple seasons of dust storms. the Curiosity Rover, which is now in its 11th year on Mars and continues to operate, has experienced several dust storm seasons. The rover itself take measurements (opens in a new tab) of the changing amount of dust accumulating on its sensors and deck, revealing how seasonal winds and dust devils help rovers keep going longer. It turns out that InSight was unlucky when it came to helping Mars clean up naturally.
No Dust Devil Car Wash
Dust devils have been seen cleaning up NASA’s older generation Mars rovers, Mind (opens in a new tab) and Opportunity. Opportunity, in particular, has been able to continue its mission for more than 14 years, exceeding its expected three-month lifespan dozens of times over. Regular dust devil sweep and wind-induced cleanup events played a significant role in this record-breaking mission. At the end, a a huge dust storm in 2019 finally brought the little rover under controlending his record-breaking voyage of discovery.
According to Mike Williams, chief engineer at Airbus Defense and Space, who is currently rethinking the dust defense approach for the The European rover ExoMars Rosalind FranklinInSight seemed to have been in a “particularly unfavorable position for dusting”.
tilting solar panels
Williams agrees that NASA’s approach of oversized solar panels is the best, safest and cheapest when it comes to dustproofing Mars exploration spacecraft. However, Airbus is currently investigating the possibility of adding a dedicated dust defense capability, and they have plenty of time to do so. The mission, built in cooperation with Russia, was suspended following the Russian invasion of Ukraine. The planned September launch has been canceled and Airbus is now storing the ExoMars rover in a clean room as some critical components, originally built by Russia, need to be replaced.
“Sizing the arrays to handle the least amount of sunlight reaching them from dust is the best and easiest solution,” Williams told Space.com. “It’s the lowest level of complexity. It requires the fewest subsystems and functions and therefore has the lowest risk. From a mission design perspective, it’s definitely the best way to proceed.”
Williams said when the ExoMars mission was first designed, engineers considered a plethora of dust-cleaning technologies, including brushes, wipers, gas blowers and electrostatic wipers to get rid of dust. At that point, they decided that the rover, whose nominal mission to Oxia Planum was designed to last only 180 Martian days, or sols, did not need to self-clean. With the new launch date now slated for no earlier than 2028, they are once again rethinking their approach.
“With the revival of ExoMars, we’re looking at eventually restoring some of that capability,” Williams said. “We could use something like tilting the solar panels to possibly dislodge some of that dust. It would also help point the panels more effectively at the sun, which could also have some benefits.”
Williams added that Airbus engineers, like those at NASA, must come to terms with the fact that ExoMars, like other spacecraft on Mars, may eventually succumb to dust, and will not be disappointed if the rover fails. only slightly exceeds the lifetime of its mission. Although they hope to get help from Martian weather, as do Spirit and Opportunity.
“It’s just, it’s just the way it is with space missions, unfortunately,” Williams said.
Attempt to self-clean InSight
Even though InSight wasn’t designed to wipe the dust off itself, NASA tried as a last resort to help the lander clear some of the dust during the last months of its life, as the amount of electricity generated by its panels was decreasing.
In May, ground controllers ordered InSight’s robotic arm to sprinkle some sand on one of the lander’s dust-covered panels. When the wind blew the grains of sand across the panel, they actually picked up some of the dust along the way, reducing the thickness of the dust cover that obstructs the sun.
The operation saved the lander about 30 watt-hours of power per ground at that time, according to a NASA report. statement (opens in a new tab).
In the end, nature won. Like always. And InSight certainly did not collapse without a fight.