After months of setbacks, NASA says the InSight Lander Mole is working again.
InSight landed on the 26th of November 2018 on Mars in Elysium Planitia. His mission is to study the inside of the planet and learn how Mars and other rocky planets formed. InSight is a NASA mission with other partners, including the DLR (German Aerospace Center).
The "Mol" (Heat Flow and Physical Properties) (HP3) package was designed and built by DLR. It penetrates into the Martian surface and measures the heat that flows from the inside of the planet. It works like a hammer drill that hits the ground and turns in it.
InSight had only one chance to use the mole, and looked around thoroughly before using it. The mission engineers used the Lander's cameras to examine the placement area of the instrument and found a spot free of obvious stones. But they could not see below the surface.
After the mission, the mole got a bit into the ground and then stopped. The InSight team thought it fell on a stone, but was not sure. They continued to work on it, and then the mole was tilted at an angle of about 1
After working through various scenarios on Earth experimental rigs, they came to the conclusion that the mole relies on friction between itself and the surrounding material to penetrate into the soil and surrounding material did not fill the hole as it did when designing and testing the mole here on earth.
The operator removed the housing of the jetty to get a better view of the hole. A few inches below the surface, they found a type of soil they call Duricrust. This Duricrust was compacted and did not fill the cavity that the mole had created when penetrating the surface.
The InSight team pushed the blade at the end of the Lander's instrument placement arm onto the ground surrounding the mole's hole. But that did not work. The instrument arm could barely reach that far, and not much power could be expended.
NASA and DLR have found another solution. This time they would use the shovel on the instrument arm to exert lateral force on the jetty. They hoped that by pressing the mole against his hole, there would be enough power and the mole would make progress again.
On October 15, NASA said things looked good, but they could not be completely sure.
NASA calls the new technique "pinning". By pushing the mole against the side of the hole, enough friction is created to allow the instrument to penetrate further. Without this friction, the mole simply jumps in place as it tries to find its way into the ground.
Now NASA confirms that the fixation technique works.
The progress of the mole seems to indicate that no stone blocks our path, "said HP 3 principal investigator Tilman Spohn of DLR. "This is great news! We are making sure that our mole continues."
There is still a long way to go. The mole is nowhere near the desired depth of five meters. But they are making progress.
"The Mole still has a long way to go, but we're all looking forward to digging it again," said Troy Hudson of JPL, an engineer and scientist who led the effort to restore the mole. "When we first encountered this problem, it was a crushing problem. But I thought, "Maybe there's a chance, let's move on." And right now I'm feeling dizzy. "
The mole is not clear yet, there's no way to know if it gets stuck again The InSight team might try to scoop dirt into the hole or press it on the exposed top of the instrument, but that's risky, with the delicate instrument leash attached at the top. 19659002] But there is progress at the moment: the maximum working depth of the mole is five meters, but it can also work scientifically at a shallow depth, it is simply not ideal and requires more work to understand the results.
With luck and possibly with more advanced problem-solving skills as the team has already deployed, the mole will be successful reveal more secrets.