NASA’s Mars InSight lander died a slow death from dust last week. Over the course of several months, the robot, built to study tectonic activity on the Red Planet, was using less and less power as its 25-square-foot (4.2-square-meter) solar array gradually disappeared under a thick layer of dust. . On Wednesday (December 21), NASA announced that there had been no word from the lander for several days, officially announcing that the mission had been completed.
InSight, which landed in the flat, seemingly uninteresting Elysium Planitia basin just south of Mars’ equator in November 2018, exceeded its expected mission duration by two years. However, many have asked if anything could have been done to save an otherwise perfectly healthy robot that has been doing pioneering research into the inner life of Mars.
RELATED: NASA’s Mars InSight lander ends mission after losing power
Cost versus benefit
In the twitter thread (will open in a new tab)Released about six weeks before InSight’s final demise, NASA explained the compromises engineers faced when developing a mission to the infamous dusty Mars.
“People often ask: isn’t there a way for me to dust myself off (wiper, blower, etc.)? It’s a fair question, and the short answer is this,” NASA wrote on the lander’s Twitter account. “Such a system would add cost, mass and complexity. The easiest and most economical way to achieve my goals was to bring solar panels large enough to power my entire mission – which they did (and then some!). “
dust storm season
When sending landers to Mars, space agencies usually try to avoid the planet’s dust storm season, which occurs during Mars’ northern autumn and winter periods. Because a year on Mars lasts roughly two Earth years, most of the latest landers and rovers, including InSight, have survived several seasons of dust storms. The Curiosity rover, which has been on Mars for 11 years and is still operating, has experienced quite a few seasons of dust storms. Rover even took measurements (will open in a new tab) about the changing amount of dust accumulating on its sensors and deck, and shows how seasonal winds and dust swirls help rovers run longer. As it turns out, InSight is out of luck when it comes to Mars’ natural cleansing aid.
Dust free car wash
It is known that dust whirlwinds cleaned NASA’s older generation Spirit rovers. (will open in a new tab) and opportunity. Opportunity, in particular, was able to continue its mission for more than 14 years, exceeding its estimated three-month service life by dozens of times. Regular dust and wind sweeps played an important role in this record-breaking mission. After all, a powerful dust storm in 2019 finally overpowered the small rover, ending its record-breaking journey of discovery.
According to Mike Williams, chief engineer at Airbus Defense and Space, who is currently rethinking the dust protection approach for the European ExoMars Rosalind Franklin rover, InSight appears to be in a “particularly disadvantageous position for removing dust.”
NASA’s InSight lander lost power due to dust covering its solar panels. (Image credit: NASA)
Inclined solar panels
Williams agrees that NASA’s approach to oversized solar arrays is the best, safest and cheapest when it comes to protecting spacecraft exploring Mars from dust. However, Airbus is currently considering adding custom dust protection and they have plenty of time to do so. The mission, set up in cooperation with Russia, was put on hold following Russia’s invasion of Ukraine. A planned September launch has been cancelled, and Airbus is now keeping the ExoMars rover in a clean room as some critical components originally built in Russia need to be replaced.
“The best and simplest solution is to size the arrays so that they can handle less sunlight that hits them because of the dust,” Williams told Space.com. “This is the lowest level of difficulty. It requires the fewest subsystems and functions, and therefore has the least risk. From a mission development standpoint, this is definitely the preferred way to accomplish it.”
Williams said that when the ExoMars mission was first conceived, engineers considered a variety of dust-cleaning technologies, including brushes, wipers, blowers and electrostatic wipers, to get rid of the dust. At that time, they decided that the rover, whose nominal mission to Oxia Planum was only 180 Martian days, did not need to self-clean. Now, with a new launch date no earlier than 2028, they are rethinking their approach again.
“Because ExoMars is now being resurrected, we are looking into restoring some of these capabilities,” Williams said. “We could use something like tilting the solar panel to perhaps remove some of that dust. It would also help direct the panels towards the sun more efficiently, which could also have some benefits.”
Williams added that Airbus engineers, like NASA engineers, must come to terms with the fact that ExoMars, like other spacecraft on Mars, may eventually die from dust, and will not be disappointed if the rover only slightly outlasts its design life. . Although they hope to get help from the Martian weather, like Spirit and Opportunity.
“It just happens with space missions, unfortunately,” Williams said.
InSight tries to clean itself
While InSight wasn’t designed to dust itself off, NASA made several final attempts to help the lander remove some of the dust in its final months, when the amount of electricity generated by its panels dwindled.
In May, ground controllers ordered InSight’s robotic arm to sprinkle sand on one of the lander’s dust-covered panels. As the wind carried the grains across the panel, they actually picked up some of the dust along the way, thinning out the sun-blocking dust cover.
The operation allowed the lander to receive about 30 watt-hours of power per sol at the time, according to a NASA statement. (will open in a new tab).
In the end, nature won. As always. And InSight definitely didn’t go down without a fight.
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