Continent-size dust storm threatens NASA's Mars InSight lander

After nearly four (Earth) years, and 1,373 sols (Martian days), the team managing NASA's InSight is working to get as much life as possible out of the nearly 20-foot wide, 789-pound lander.

The lander has long-since surpassed its primary mission and is now close to the end of its extended mission, conducting “bonus science” by measuring marsquakes, which reveal details about the deep interior of the Red Planet.

Since deploying its sensitive seismometer in December 2018, the mission has recorded meteorite hits and more than 1,300 quakes, most between magnitude 2 and 4. On May 4, 2022, the mission recorded a magnitude 5 quake, the largest recorded on another planet.

As seismic waves pass through or reflect off material in Mars’ crust, mantle and core, they change in ways that reveal the depth and composition of these layers to seismologists. What scientists learn about the structure of Mars can help them better understand the formation of all rocky worlds, including Earth and the Moon.

Data from InSight found Mars' core to be about half the size of Earth's core, a surprise to scientists who expected it to be bigger based on prior research. This suggests the core is likely made up of lighter elements than previously thought.

Like other solar powered missions before it, InSight's lifespan is limited by dust as fine as talc that hangs in the atmosphere and gathers on the mission's seven-foot solar panels.

Wind periodically clears some of that dust. If just 25% of InSight’s panels were swept clean by the wind, the lander would gain about 1,000 watt-hours per sol, enough to power all the science instruments. But that hasn't happened in while, and the skies are getting hazier above InSight.

A continent-size dust storm was spotted by the Mars Reconnaissance Orbiter (MRO) on Sept. 21. The storm was about 2,175 miles (3,500 kilometers) from InSight and initially had little impact on the lander. Power production had dropped by one-third as more dust is lofted into the atmosphere the first week of October.

“We were at about the bottom rung of our ladder when it comes to power. Now we’re on the ground floor,” said project manager, Chuck Scott of NASA’s Jet Propulsion Laboratory. “If we can ride this out, we can keep operating into winter – but I’d worry about the next storm that comes along.”

The science team has been experimenting with techniques to remove dust throughout the extended mission

In 2020, they pulsed the motors originally used to deploy the solar panels in an effort to shake dust off. But by February, 2021, the solar panels were producing just 27% of their capacity.

In May 2021, they came up with the counterintuitive technique of trickling sand from the scoop on InSight’s robotic arm next to the panels, allowing a 13-mph wind to scour panels a bit cleaner. The experiment produces a modest bump in power production of 30 watt-hours per day.

Since then, power saving measures have focused on shutting down instruments not related to gathering seismic data. The science team took one last "selfie" in April to document the progression of dust on the rover and stowed the robotic arm,

NASA estimates InSight’s mission will end sometime between late October of this year and January 2023.