NASA's InSight doomed as Mars dust coats solar panels
The little lander that couldn't (any longer)
The Martian InSight lander will no longer be able to function within months as dust continues to pile up on its solar panels, starving it of energy, NASA reported on Tuesday.
Launched from Earth in 2018, the six-metre-wide machine's mission was sent to study the Red Planet below its surface. InSight is armed with a range of instruments, including a robotic arm, seismometer, and a soil temperature sensor. Astronomers figured the data would help them understand how the rocky cores of planets in the Solar System formed and evolved over time.
"InSight has transformed our understanding of the interiors of rocky planets and set the stage for future missions," Lori Glaze, director of NASA's Planetary Science Division, said in a statement. "We can apply what we've learned about Mars' inner structure to Earth, the Moon, Venus, and even rocky planets in other solar systems."
The mission didn't go quite as planned. The spacecraft was designed to stick its fancy heat probe five metres into the Martian regolith to take the planet's temperature. But the long rod, nicknamed the mole never made it that far down since the soil was too loose to compress around the apparatus and provide enough resistance to burrow through. The heat probe was also often prone to popping out.
Still, Glaze said InSight has gathered valuable data for science. "The InSight mission has really just been an incredible mission for us," Glaze said during a briefing.
"It's given us a glimpse of Mars that we couldn't get from any other spacecraft in our NASA Mars fleet. An interpretation of the Insight data has really furthered our understanding of how rocky planets form throughout the universe. It's not just telling us information about Mars, but broadening our planetary science understanding and helping us think differently about other rocky planets across the Solar System, and beyond."
Don't know why, there's no sun up in the sky, dusty weather
The lander's days are numbered, however, as it struggles to obtain enough energy to continue operating its instruments. When it just landed on Mars, its solar panels were able to produce 5,000 watt-hours every Martian sol, apparently equivalent to powering an electric oven for an hour and 40 minutes. But now it's only generating about a tenth of that.
Its energy levels have dropped, and are dropping, because Martian dirt is gathering on and blocking its solar panels, and the hours of sunlight are dwindling as winter approaches the lander. Bruce Banerdt, InSight's principal investigator at NASA's Jet Propulsion Laboratory, said the only way InSight could be revived is if a so-called dust devil, a powerful whirlwind, miraculously blows away the dirt on the panels.
If just 25 percent of the dust is removed, InSight could produce 1,000 watt-hours per sol and have enough power to continue collecting data. But its declining rate energy levels coupled with the low chance of an automatic spring clean from an incoming dust devil has led NASA to start preparing for its final demise.
"We've been hoping for a dust cleaning like we saw happen several times to the Spirit and Opportunity rovers. That's still possible, but energy is low enough that our focus is making the most of the science we can still collect," Banerdt said. InSight's robotic arm will eventually be placed in a retirement pose, its seismometer is expected to wind down, and all science operations will cease.
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NASA engineers came up with a way to extend InSight's mission, Kathya Garcia, InSight deputy project manager at JPL, explained during the briefing for the media.
"We had a really clever idea of trying to figure out how we can actually clean the solar panels," Garcia said. "We use the arm to scoop the dirt transported over the lander, and we slowly let the dirt fall onto the deck of the lander so that the dirt is carried over by the solar winds across the solar panels, cleaning it."
Garcia said the InSight team performed this motion successfully six times, extending the seismometer's run time by about six weeks. This in turn allowed NASA to detect this month its largest Mars quake yet, estimated to be a magnitude-five shake. But this technique is not enough to keep the lander from petering out.
After its instruments are powered down over our summer, InSight will live out the end of its days in a weakened state until its energy levels are completely drained. ®