To remove some dust from one of its solar panels, NASA’s InSight lander trickled sand over the panel. The grains of sand carried by the wind then picked up some dust on the plate, which enabled the lander to generate around 30 watt hours of energy per sol on May 22, 2021, the 884th Martian day of the mission. NASA / JPL-Caltech
It is not easy to power a robot on Mars. NASA rovers like Curiosity and Perseverance use a nuclear power system, but other explorers like the InSight lander rely on solar energy. The good news is that the sun is a constant source of energy. The bad news is that Mars is a very dusty place and dust eventually covers solar panels and prevents them from functioning. That happened to the now defunct Opportunity Rover, which ran out of power during a dust storm and prevented its solar panels from charging.
So the InSight team came up with a counter-intuitive approach to addressing this issue that they recently tried: They made the lander dump more dirt on itself.
The team has been thinking about how to tackle the power supply problem for a year and has tried other approaches, such as using motors to stir the dust – but to no avail. So they decided to try something wild: they used the lander’s robotic arm to scoop up some sand and trickle it next to a solar panel. The wind picked up the sand and blew it over the slab, which carried away some of the dust with it.
This surprising approach resulted in an improvement of 30 watt hours of energy per Martian day.
“We weren’t sure this would work, but we’re glad it worked,” said Matt Golombek, a member of the InSight science team at NASA’s Jet Propulsion Laboratory, in a statement.
The energy issue becomes pressing as Mars is soon approaching aphelion, or the point at which it is furthest from the Sun. That means there is less solar energy available, and although the lander has turned off many of its scientific instruments to minimize power consumption during the cold season, it still needs enough power to keep its heaters and computer running.
InSight’s mission was recently extended by two years, but we’ll have to wait and see if the dust management approach delivers enough power to keep the lander running. “While it is not a guarantee that the spacecraft will have the required performance, the recent cleaning will add a helpful margin to InSight’s power reserves,” NASA wrote.