The InSight mission, which listens to the interior of Mars, is doomed

It arrived on Mars at the end of November 2018 for an unprecedented mission which was initially to last one Martian year, i.e. two Earth years, and here it is now, in its extended operating phase, forced to stop one by one its measuring instruments and soon to completely cease its scientific activities. Blame it on the dust that obscures its large solar panels 2.20 meters in diameter. And it’s not going to work out at all, indicates NASA, which predicts a weather report increasingly unfavorable in the coming months in the region where the lander has deployed. Even more dust lifted into the sky and threatening to fall out.

InSight will thus experience the same fate as its pioneer cousins ​​in the exploration of the surface of the Red Planet, the rovers Spirit and Opportunity. Their only source of power being their solar panels, the dust that has accumulated over the years has therefore ended up getting the better of them. However, NASA is not yet throwing in the towel, because it still hopes, as has happened so often for the little ones roveronly whirlwinds of dust, the famous dut devils, pass by and rid their big solar “wings” a bit. This would provide him with a significant reprieve from his activities: “If only 25% of the panels ofInSight were swept away by windthe lander would gain about 1,000 watt-hours per sol (Martian day), enough to continue collecting scientific data.explains the Space Agency.

The Seis seismometer will soon be shut down

Currently, in mid-May 2022, InSight only benefits from 500 watt hours per day, that is to say 10 times less than when it arrived. The team that takes care of robot plans to put by the end of the month its robotic arm (which was very useful to him) permanently in a resting position. His main instrument, the Seis seismometerwill continue its “eavesdropping” from inside Mars, but intermittently, only at night, when the wind has died down and no longer interferes with the detection of interior humming. Since the beginning of its mission, InSight has already recorded 1,300 Mars tremors! Remember that this is the first time that scientists have obtained measurements from the interior of a planet other than Earth. The strongest of all earthquakes was recorded recently, in early May. Of magnitude 5, it is even possible to listen to it.

If the situation does not improve, the operators plan to shut down the seismometer during the summer. InSight will not be dead for all that, because the littleenergy that he will still be able to collect every day will allow him to wake up from time to time to send us some postcards. Nevertheless, the team estimates that it could cease all communication with Earth at the end of this year. For now, InSight is staying tuned and its hundreds of detections already made have yet to reveal all the secrets of the core and coat of Mars, our neighbour.

The end is near for InSight, the lander that listens to the heartbeat of Mars

Article of Nathan Le Guennic published on February 13, 2022

After a two-year mission, and an equally long extension, the Martian lander is inexorably reaching the end of its life, scheduled for this summer. Explanations.

On May 5, 2018, a rocket Atlas V 401, the rocket the most reliable there is, takes InSight – the result of a collaboration between Germany, France and the United States – to the distant world of Mars. InSight is a lander that takes the first seismometer designed to pierce information about the interior of the Red Planet, because if the first Martian seismometers date from the probes viking, they were in practice unusable for detecting and analyzing possible Martian earthquakes. On November 26 of the same year, the 358-kilogram lander discovered the desolate landscape of Elysium Planitia, a region near theequator Martian, which will be his final resting place.

The end is coming

Unfortunately, all good things come to an end, and InSight is no exception. The small probe is now completely covered with Martian dust and more and more, which will prevent the solar panels from providing energy and which, within a few months, will cause the death of the probe.

Let’s keep our tears, the probe has more than fulfilled its mission! All space probes are designed for duration nominal mission, and can, if successful, benefit from a mission extension. This was the case for InSight which completed its objectives in 2020 and which has been able to continue to collect valuable data until today. But, as for old probes equipped with solar panels, life is not eternal on the red planet.

The teams in charge of the mission have nevertheless succeeded in extending the life of the probe in an unprecedented way. To remove some of the dust, one technique that worked was to… add more dust! Thanks to the small shovel that equips the platform, the engineers were able to throw a pile of dust on the panels, and the fall made it possible to a certain extent to sweep, in a way, the surface and to grab a little more light. In other cases, the storms and the winds of Mars also make it possible to sweep the panels and lengthen thelife expectancy robots, as may have benefited the Opportunity rover for example.

If such an event occurs and InSight can be cleaned up like Opportunity, the probe has plans for a new mission expansion, but such an eventuality is considered unlikely according to officials.

Why not clean the solar panels?

Dust can be cleaned well, however, so why didn’t the teams in charge think of including a small broom or a small blower? Of course, they thought about it, it’s their job, but there are several reasons that make any such attempt impossible. The first is very simple: mass. Adding a system to propel air or to sweep means adding more weight and constraining the success of the mission even more. On the other hand, this also represents an additional cost, even for small instruments, not to mention the specifications which become heavier on a project which is already calculated and dimensioned in an optimal way, from the point of view of the mass, but also electrical energy.

The other reason is that a compressed air system does not remove fine dust, we can experience it at home: blowing is effective against large dust bunnies, but for fine dust that has stuck over the years to the old furniture, you have to scrub. For Martian dust, it is even worse, it is very fine and thanks to the effects electrostaticit adheres enormously to surfaces, it sticks.

A small brush then? No more ! In addition to being very sticky, Martian dust is very abrasive. Trying to sweep it would reduce the life of our dear probe even more quickly.

In summary, a lot of additional stress for not much, because the dust on the solar panels is not the only predator of our martian robots. phoenix, twin from InSight, landed very far north of the planet, this is the dry ice and the cold that got the better of him. For Spirit, he got bogged down in the sandimmobilized in a position which deprived its solar panels of light, dust or not, it ended up going out.

Its twin Opportunity has enjoyed remarkable longevity, martian winds allowed him to clean himself regularly, but after 14 years he was caught in a vast global dust storm, which covered not only his panels, but the whole sky. the Sun then disappeared gave way to a long darkness, ending the rover’s odyssey, no brush could have saved it.

Alone Zhurong, the Chinese rover, will experiment with cleaning its solar panels. They are covered with a special coating that should prevent dust from sticking to them. Then the panels should rise vertically to just let the dust fall out.

And Curiosity or Perseverance then?

The two behemoths of Mars exploration, which arrived on Mars in 2012 and 2021 respectively, do not experience this kind of problem, because they simply do not have solar panels.

The reason is that solar panels are very inefficient, because the planet Mars is quite far from the Sun. Solar power may be appropriate for small probes with fewer instruments on board, not for large rovers.

Nope, Perseverance and Curiosity are themselves equipped with generators radioisotope thermoelectrics (RTGs), which use the heat generated by the radioactivity (from plutonium in general) to generate electricity (not to be confused with the principle of our nuclear center which use nuclear fission to generate heat, not radioactivity). This principle has the advantage of being able to power a large number of scientific instruments, and therefore to power a larger rover, and for years to come, without depending on sunlight. On the other hand, it is an extremely expensive technology which would not be suitable for small probes like InSight financed by smaller budgets.

Ultimately, we need to let InSight enjoy its final months and remember it as the probe that first revealed the mysterious interior of the planet of the god of war.