There’s more trouble on Mars for NASA’s InSight lander, which has been fighting a battle to free its stuck heat probe (or mole) for more than a year.
The mole has been making progress recently, thanks to the use of the lander’s arm to push down on its back cap and embed it in the soil. However, NASA scientists now aren’t sure if it will be able to dig deep enough to collect the data on temperatures that is needed.
The problem is that the mole needs to dig down at least 3 meters (almost 10 feet) into the soil. Normally, it uses friction from the soil to push itself deeper with its self-hammering action. But the soil where InSight has landed is different from what was expected, and turns out to be tightly packed. The mole needs loose soil to create friction which allows it to move, but the soil where it is located is “cement-like,” according to NASA, consisting of duricrust with grains that tend to stick to each other.
This means the self-hammering action isn’t working as well as it should, and the mole may not be able to dig deep into the soil.
Tilman Spohn, the principal investigator for InSight’s HP3 instrument, explained more in a blog post: “The team continues to be determined, although we appreciate that the task is not likely to become easier,” he wrote. The team had prepared for the possibility that their current plan would not work, so now they need to swing InSight’s arm out of the way so they can investigate the hole with InSight’s cameras.
“We will be interested to see how deep in the Mole really is (it should be a centimeter or so below the surface), whether the morphology of the pit has changed and whether the sand that we had seen in the pit is still there or whether the pit has been drained by the hammering action,” he wrote.
Even with these problems, InSight will still keep working. It will continue to use its other instruments, such as its seismometer for detecting marsquakes, which can tell scientists more about the activity below the planet’s surface.