Not All NASA Robots Succeed

Insight is a stationary robot NASA has sent to Mars. One component of this robot is called "the mole" which buries its way into the Martian soil by hammering itself into the ground. However, the probe tipped and probe failed to dig itself deeper into the soil. After many attempts to correct the problem, NASA has retired the probe. The probe was developed and built by the German Aerospace Center (DLR) and deployed on Mars by NASA’s InSight lander has ended its portion of the mission. The probe, called the “mole,” has been attempting to burrow into the Martian surface to take the planet’s internal temperature, providing details about the interior heat engine that drives the Mars’ evolution and geology. But the soil’s unexpected tendency to clump deprived the spike-like mole of the friction it needs to hammer itself to a sufficient depth. After getting the top of the mole about 2 or 3 centimeters under the surface, the team tried one last time to use a scoop on InSight’s robotic arm to scrape soil onto the probe and tamp it down to provide added friction. After the probe conducted 500 additional hammer strokes on Saturday, Jan. 9, with no progress, the team called an end to their efforts.

The unexpected properties of the soil near the surface next to InSight will be puzzled over by scientists for years to come. The mole’s design was based on soil seen by previous Mars missions – soil that proved very different from what the mole encountered. For two years, the team worked to adapt the unique and innovative instrument to these new circumstances. “The mole is a device with no heritage. What we attempted to do – to dig so deep with a device so small – is unprecedented,” said Troy Hudson, a scientist and engineer at NASA’s Jet Propulsion Laboratory in Southern California who has led efforts to get the mole deeper into the Martian crust. “Having had the opportunity to take this all the way to the end is the greatest reward.” Besides learning about the soil at this location, engineers have gained invaluable experience operating the robotic arm. In fact, they used the arm and scoop in ways they never intended to at the outset of the mission, including pressing against and down on the mole. Planning the moves and getting them just right with the commands they were sending up to InSight pushed the team to grow. They’ll put their hard-earned wisdom to use in the future. The mission intends to employ the robotic arm in burying the tether that conveys data and power between the lander and InSight’s seismometer, which has recorded more than 480 marsquakes. Burying it will help reduce temperature changes that have created cracking and popping sounds in seismic data.



Credits:
https://www.nasa.gov/feature/jpl/nasa-insight-s-mole-ends-its-journey-on-mars
https://www.nasa.gov/feature/jpl/insights-team-tries-new-strategy-to-help-the-mole