End of mission after four years of work: NASA announced on Wednesday December 21 that it had lost contact with Mars with its InSight probe, which was listening to the interior of the red planet to reveal its secrets. An expected outcome, the probe having for several weeks only very little energy remaining, due to the Martian dust accumulated on its solar panels. A phenomenon that had been anticipated from the start by the American space agency.
“If saying goodbye to a spacecraft is always sad, the fascinating scientific work conducted by InSight is cause for celebration”, Thomas Zurbuchen, associate administrator at NASA, said in a statement. Equipped with an ultra-sensitive French-made seismometer, InSight recorded more than 1,300 “Marsquakes”, some of which were caused by meteorite impacts. One of them, which occurred a year ago, was so powerful that it hurled blocks of ice onto the Martian surface.
The last signal received from InSight was on December 15. Since then, NASA has tried to contact him twice, without success, leading the teams to conclude that the probe’s batteries were now flat. The US space agency will continue to listen for a possible signal, ” just in case “but this eventuality is considered as ” very unlikely “she explained in a press release.
Knowledge of the inner layers of Mars
Thanks to the analysis of the seismic waves crossing the bowels of the planet, the mission made it possible to learn more about the interior layers of Mars. For example, the scientists were able to confirm that its core was indeed liquid, and to determine the thickness of the Martian crust, less dense than previously envisaged.
The mission had already been extended thanks to a daring cleaning of the solar panels: the robot arm had dug into the ground, and gently dropped Martian soil on itself during windy days. The wind then carried away this earth, sweeping with it part of the dust accumulated on the panels. A washing mechanism had not been on board for cost reasons, as this would have taken the place of a scientific instrument.
The InSight probe arrived on Mars in November 2018, and operated in collaboration with the French National Center for Space Studies (CNES). The mission also experienced a failure: an instrument had to be buried a few meters deep below the surface, to take the temperature of the planet. But the composition of the ground at the landing site had prevented this « taupe » to sink as expected.
Eventually buried about 40 centimeters deep, it still provided “valuable data on the physical and thermal properties of the Martian soil”pointed out NASA.