NASA's latest robot on Mars " the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander " appears to have freed itself from a sticky situation some 225 million kilometres from home. The mission's engineers are confident there's hope for an important instrument on the lander " dubbed "the mole"" to resume its heat-sensing experiments since it got stuck in the red dirt in February 2019.
The InSight mission landed on Mars in late November 2018 to explore Mars' Elysium Planitia, a broad plain that straddles the planet's equator. The InSight lander's objective is to study the planet's interior " to learn how Mars and other rocky planets formed. It was performing hitch-free till the mole stopped working " with few clues as to what caused it to stop functioning normally. Last week, engineers at the German Aerospace Center (DLR, which built the mole), and NASA announced that they have been trying for over seven months to get the probe moving again. Basis a new update from DLR and NASA, it looks like they've succeeded.
"Good news from Mars! After 3 cm progress, it appears the DLR 'Mole' on NASA InSight was not stopped in its tracks by a rock under the Martian surface but had in fact lost friction," the DLR said in a recent tweet.
Good news from #Mars! Confirmed! After 3 cm progress, it appears the @DLR_de 'Mole' on @NASAInSight was not stopped in its tracks by a rock under the Martian surface but had in fact lost friction. #MarsMaulwurf pic.twitter.com/WGQYdSv7FF
" DLR - English (@DLR_en) October 14, 2019
The InSight team tried to used the scoop on the end of the lander's instrument placement arm to push down on the soil around the Mole's incomplete dig site, which didn't work as planned. The instrument arm couldn't reach that far, and couldn't apply the necessary force even if it did. NASA and the DLR attempted a second strategy " using the scoop arm to apply sideways force on the Mole. Pushing the Mole against its hole worked, and the Mole is making progress again.
" NASA InSight (@NASAInSight) October 15, 2019
This new technique, called "pinning" by NASA, pinned the Mole against the side of the hole, giving it enough friction to continue digging. Without this friction, the Mole will just "bounce in place" trying to hammer into the ground. The mole is part of a toolkit in the lander's Heat Flow and Physical Properties Package (HP3) instrument.
" NASA InSight (@NASAInSight) October 17, 2019
During the 7-month troubleshooting process, engineers had to evaluate whether it was simply a problem of re-establishing and maintaining friction (to which a solution exists), an instrument failure (with no apparent solution), or an unlucky encounter with a tough Martian boulder.
The mole and the HP3 specifically, make up two key instruments in the mission. The other instrument is a seismograph, which records quakes on Mars. The pair of instruments are being used by NASA to create a comprehensive 3D map of Mars' insides. Researchers expect the InSight mission's findings will go a long way towards understanding how Mars and other rocky planets were formed, and how they have evolved in the billions of years since.
The popular opinion among geologists thus far has been that the quakes on Mars and the Moon have nothing to do with tectonic plates, like they do here on Earth. On Mars, scientists suspected that quakes were caused by the slow cooling of the planet's core over millions of years, which may trigger sporadic quakes as energy sweeps through the interior of the planet. InSight's discovery of a confirmed Marsquake was big news indeed, but its longer mission, to study Mars' interior, is quite the challenge.
InSight still has a decade and a half of exploring to do and to dig up more answers about Mars and its past. The mole, if completely unstuck and free to continue digging to its intended depth of 3 to 5 meters, could contribute a lot towards improving the 3D maps that come from the mission.