NASA announced in May that its InSight Mars lander—a spacecraft that has spent nearly four years investigating Martian geology and seismic activity—would likely cease scientific operations in mid-summer and terminate all operations by the end of the year, due to low power levels. Now, the agency plans to stretch InSight’s scientific endeavors until late August and possibly even early September, in the hopes of detecting some final Marsquakes before the lander goes dark.
There is a trade-off, though. By pushing the lander’s scientific agenda, its solar-powered batteries will discharge sooner. That means InSight’s death knell will come sooner than the end of the year, as NASA previously estimated.
“InSight hasn’t finished teaching us about Mars yet,” said Lori Glaze, director of NASA’s Planetary Science Division in Washington, in an agency release. “We’re going to get every last bit of science we can before the lander concludes operations.”
Since InSight landed on Mars in November 2018, the lander has detected over 1,300 Marsquakes which have clued scientists in to the structure of the Martian interior. Some of InSight’s operations were less successful, most notably its Mole, an instrument that was supposed to dig 10 feet into the Martian surface but only made it a few inches in, due to the unexpected consistency of the soil.
InSight has been dying for a long time. When the lander first arrived on Mars, its two 7-foot-wide solar panels were soaking up as much sunlight as they could; the lander could run for about 5,000 watt-hours per Martian day, or sol.
Since then, dust from the Martian landscape has settled on the panels, and now InSight cannot draw nearly as much power from sunlight. In a May press conference, members of the InSight team said that the lander could only manage 500 watt-hours per sol.
InSight’s seismometer is the only instrument still operational on the lander. To maximize the seismometer’s runtime, the team is turning off the lander’s fault protection system—the system that automatically puts InSight into safe modes in situations like dust storms, cold fronts, or when the lander has low power.
So InSight will be exposed to threats in its last months, but the team at NASA is betting that the data the lander collects in that time is worth the risk.
“The goal is to get scientific data all the way to the point where InSight can’t operate at all, rather than conserve energy and operate the lander with no science benefit,” said Chuck Scott, InSight’s project manager at NASA’s Jet Propulsion Laboratory, in the NASA release.
The InSight team has tried some unconventional means of getting the dust off the solar panels—even dropping more dirt on them—but the lander is now operating on borrowed time. For future solar-powered Martian machines, perhaps some dusting mechanism could be useful for keeping solar panels clean—but that’s a whole other engineering challenge.