Clever Trick Used to Clean off InSight’s Solar Panels and Boost its Power
Ever have an idea that was so crazy it could work? A few weeks ago, members of the InSight Mars team came up with a crazy, non-intuitive way to try and remove dust from the lander’s solar panels: pour * more * dust on the panels.
Yeah, that sounds crazy. But yes, it actually worked!
“I’ve wanted to tell people for a while why we got buried in the dirt,” said Mark Panning, scientist with the InSight project, on Twitter. “Short answer: People like Matt Golombek, Mariah Baker, Ralph Lorenz and others convinced our engineers that we can remove dust from the panels by adding sand. That sounds crazy! But if you throw off a pile of earth so that the wind carries grains of sand onto the plate, grains of sand can jump over the plate and throw off dust.
If my solar panels are gathering dust, why should I pour more dirt on myself? My team asked me to try something that seems crazy, but it actually worked! It cleaned some dust off my solar panels and gave me a little boost of energy.
This is how it works: https://t.co/v2l5foSqsl pic.twitter.com/oOKBCRcB86
– NASA InSight (@NASAInSight) June 3, 2021
This clever trick increased InSight’s energy production by around 5% and gained around 30 watt hours of energy per sol or Martian day. The team repeated the process last weekend in the hope of gaining even more performance.
“It’s not huge, but we’re getting all we can out of every watt-hour of energy,” added Panning. “This will allow us to keep collecting as much data as possible as we move to Aphelion, where solar energy is low and heat demand is high.”
In aphelion, Mars is furthest from the Sun. This means that less sunlight reaches the spacecraft’s dust-covered solar panels and reduces their energy output. Martian dust was not only a nemesis for InSight, but also for previous Mars ships on the surface, such as the Opportunity rover, which ran out of power in 2018.
The InSight team was hoping that a dust devil could remove the dust from the panels, as it did with the Mars rovers Spirit and Opportunity. Unfortunately, no luck, and so the team took matters into their own hands … uh, robotic arm.
Raw image of the InSight lander showing the robotic arm dumping dust on the lander. Photo credit: NASA / JPL.
The InSight team planned the insane maneuver for the windiest part of the day, hoping that the larger grains of sand blowing around would remove the smaller dust particles from the surface of the panels. In fact, with winds blowing at a maximum of 6 meters per second from the northwest, the dribbling of sand coincided with an instant increase in the overall performance of the spacecraft, NASA said.
“We weren’t sure if that would work, but we’re glad it worked,” Golombek said in a press release.
It has long been known that Martian dust has electrostatic “sticky” tendencies – which makes it stick to the solar panels of all rovers and landers. The idea of “using more dust to create less dust” came about when the aforementioned team members and Constantinos Charalambous saw a similar effect when they used InSight’s robotic arm to drip soil over the seismometer’s tether to better isolate it. They saw dust blowing downwind at the dumps to bury the line.
One ball, two balls, three, four, five! I use my robotic arm to drip soil over my seismometer lanyard to better isolate it while listening for marsquakes. I’ve already seen hundreds of quakes. pic.twitter.com/CdFqZiwf1Q
– NASA InSight (@NASAInSight) May 12, 2021
InSight’s panels have outlived the main two-year mission for which they were designed and are now powering the spacecraft during its two-year extension. NASA says the use of solar panels for power allows such missions to be as easy as possible to launch and require fewer moving parts – and therefore fewer potential points of failure – than other systems. Equipping the spacecraft with brushes or fans to remove dust would add weight and failure points.
NASA noted how some members of the public have suggested using the whirring blades of the Ingenuity Mars Helicopter to remove the panels from InSight, but that again is not an option: the operation would be too risky and the helicopter is roughly 3,452 Miles away. Path.