NASA’s InSight lander has been on the red planet since 2018, and it relies on solar panels for power, unlike the nuclear-powered Perseverance rover. That means there’s the potential for dust build-up on the solar panels, which is becoming an issue as the planet descends into another frigid winter. Luckily, engineers at JPL devised an ingenious way to get the sand off the solar panels. All it took was more sand.
InSight got its mission extension in early 2021, shortly before the team decided to give up on the burrowing HP3 heat probe that stubbornly refused to burrow. However, the SEIS instrument has exceeded expectations as the first seismometer on another planet. The team has been working to wrap up InSight’s science operations for the season. The robot was designed to go quiet during the long Martian winter to save power for its heater and communication gear. Maybe there’s a little wiggle room, though?
As expected, dust accumulation on the lander’s solar panels has lowered the amount of power it can draw. This is of greater concern now when sunlight is harder to come by on Mars. The team has been fiddling with various methods to clear dust from the solar panels — for example, they tried pulsing the solar panel deployment motors, which failed to dislodge any of the dust.
Starting on May 22nd, the team started trying something different. They instructed InSight to use its robotic arm scoop to collect some more Martian soil and dump it on the panels. They waited until midday on Mars, which is the windiest time of day. With the wind blowing past at a healthy 20 feet (6 meters) per second, most of the sand was caught up in the wind. The team hoped that some of it would “saltate,” meaning the grains bounced or tumbled across the solar panel. In theory, this would cause smaller grains on the panel to be swept away.
Sure enough, the lander reported a rise in power levels after the sand-dumping operation was complete. InSight is now eking out another 30 watt-hours of energy per sol. The lander has a maximum capacity of 4.6 kilowatt-hours, but the gain is still enough to extend science operations for a few additional weeks. InSight will still shut down over the summer, coming back online in August when Mars begins moving closer to the sun. That won’t be the last time the mission has to go offline, but this saltate sand bath could become a regular process to stretch science operations just a bit further.