That troubled “Mole” heat probe on NASA’s InSight Mars mission is presently fully covered with Martian sand. The plan now calls for the Mole to be pushed a little deeper into the ground with the continued help of the spacecraft’s robotic scoop.
The save the Mole script calls for not pressing the Mole with the robotic arm’s blade, but with the shovel at an angle of 20 to 30 degrees with respect to the surface.
Reports Tilman Spohn, the Mole leader at the German Aerospace Center’s (DLR) Institute of Planetary Research in Berlin:
“However, because we can only operate once a week – mostly for cost reasons – this will take another while. Our first operation, bringing the Mole still a few centimeters deeper in has begun and should be finished in about a month time.”
Balancing force
Following that month there will be a test of whether the Mole is moving on its own.
“Should that test not provide the required result we will move to the final activities of filling the Mole hole completely and press on the sand in the filled hole. That operation should definitely provide the necessary balancing force but may take another 2-3 months,” Spohn adds. “Having the mole deeper in will still be of advantage should we need to go to filling the hole entirely.”
“I think, at the latest after filling the pit,” Spohn explains, “we should be able to counter the recoil with sufficient force and the Mole will hopefully ‘dig’ deeper into the Martian soil on its own.”
Recent measurement
As a supporting indication, Spohn notes that a recent measurement of the thermal conductance from the Mole to the regolith shows increased values over earlier measurements.
“This suggests that both the thermal and mechanical contact have improved,” Spohn concludes. “So we’re feeling optimistic!”
Designed to burrow in as much as 16 feet (5 meters) underground to gauge the heat escaping from the Red Planet’s interior, the Mole has only been able to partially bury itself since it started hammering…way back in February 2018.
InSight landed on November 26, 2018, softly touching down within the smooth plains of Elysium Planitia. The goal of the mission is to study the interior of Mars and take the planet’s vital signs, its pulse, and temperature.