InSight Mars lander uncovers the 'mole'

InSight Mars lander uncovers the 'mole'
On June 28, 2019, NASA's InSight lander used its robotic arm to move the support structure for its digging instrument, informally called the "mole." This view was captured by the fisheye Instrument Context Camera under the lander's deck. Credit: NASA/JPL-Caltech

Behold the "mole": The heat-sensing spike that NASA's InSight lander deployed on the Martian surface is now visible. Last week, the spacecraft's robotic arm successfully removed the support structure of the mole, which has been unable to dig, and placed it to the side. Getting the structure out of the way gives the mission team a view of the mole - and maybe a way to help it dig.

"We've completed the first step in our plan to save the ," said Troy Hudson of a scientist and engineer with the InSight mission at NASA's Jet Propulsion Laboratory in Pasadena, California. "We're not done yet. But for the moment, the entire team is elated because we're that much closer to getting the mole moving again."

Part of an instrument called the Heat Flow and Physical Properties Package (HP3), the self-hammering mole is designed to dig down as much as 16 feet (5 meters) and take Mars' temperature. But the mole hasn't been able to dig deeper than about 12 inches (30 centimeters), so on Feb. 28, 2019 the team commanded the instrument to stop hammering so that they could determine a path forward.

Scientists and engineers have been conducting tests to save the mole at JPL, which leads the InSight mission, as well as at the German Aerospace Center (DLR), which provided HP3. Based on DLR testing, the soil may not provide the kind of friction the mole was designed for. Without friction to balance the recoil from the self-hammering motion, the mole would simply bounce in place rather than dig.

On June 28, 2019, NASA's InSight lander used its robotic arm to move the support structure for its digging instrument, informally called the "mole." This view was captured by the fisheye Instrument Context Camera under the lander's deck. Lifting the support structure had been done in three steps, a bit at a time, to ensure the mole wasn't pulled out of the surface. Moving the structure out of the way will give the InSight team a better look at the mole and allow them to try to help it dig. Credit: NASA/JPL-Caltech

One sign of this unexpected soil type is apparent in images taken by a camera on the : A small pit has formed around the mole as it's been hammering in place.

"The images coming back from Mars confirm what we've seen in our testing here on Earth," said HP3 Project Scientist Mattias Grott of DLR. "Our calculations were correct: This cohesive soil is compacting into walls as the mole hammers."

The team wants to press on the soil near this pit using a small scoop on the end of the robotic arm. The hope is that this might collapse the pit and provide the necessary friction for the mole to dig.

On June 28, 2019, NASA's InSight lander used its robotic arm to move the support structure for its digging instrument, informally called the "mole." This view was captured by the Instrument Deployment Camera on the spacecraft's robotic arm. Lifting the support structure had been done in three steps, a bit at a time, to ensure the mole wasn't pulled out of the surface. Moving the structure out of the way will give the InSight team a better look at the mole and allow them to try to help it dig. Credit: NASA/JPL-Caltech

It's also still possible that the mole has hit a rock. While the mole is designed to push small rocks out of the way or deflect around them, larger ones will prevent the spike's forward progress. That's why the mission carefully selected a that would likely have both fewer rocks in general and smaller ones near the surface.

The robotic arm's grapple isn't designed to lift the mole once it's out of its support structure, so it won't be able to relocate the mole if a rock is blocking it.

The team will be discussing what next steps to take based on careful analysis. Later this month, after releasing the arm's grapple from the support structure, they'll bring a camera in for some detailed images of the mole.


Explore further

InSight's team tries new strategy to help the 'mole'

More information: A Q&A with team members about the mole and the effort to save it is at: mars.nasa.gov/news/8444/common … about-insights-mole/
Provided by NASA
Citation: InSight Mars lander uncovers the 'mole' (2019, July 1) retrieved 12 November 2019 from https://phys.org/news/2019-07-insight-mars-lander-uncovers-mole.html
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