After having recorded more than 1,300 “tremors” on the red planet, the spaceship, short of energy, has not emitted signal since December 15.
Mo12345lemonde with AFP
End of mission after four years of work: NASA announced Wednesday, December 21, having lost contact on March with its insight probe, which listened to the interior of the red planet to reveal its secrets. An expected outcome, the probe having for several weeks only very little remaining energy, due to the Martian dust accumulated on its solar panels. A phenomenon that had been anticipated by the American space agency from the start.
“If to say goodbye to a spacecraft is always sad, the fascinating scientific work carried out by Insight is a reason to rejoice,” Thomas Zurbuchen, an associated director of NASA, said in a statement. Equipped with an ultrasensible French manufacturing seismometer, Insight recorded more than 1,300 “March tremors”, some of which caused by meteorite impacts. One of them, which occurred a year ago, was so powerful that he projected blocks of ice on the Martian surface.
The last signal received from Insight dates from December 15. Since then, NASA has tried to contact him twice, without success, bringing the teams to conclude that the probe batteries were now flat. The American spatial agency will continue to stretch a possible signal, “just in case”, but this possibility is considered “very unlikely”, she explained in a press release.
Knowledge of the interior layers of Mars
Thanks to the analysis of seismic waves crossing the bowels of the planet, the mission made it possible to learn more about the interior layers of March. Scientists have for example been able to confirm that his nucleus was 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 the ground, and gently fall from the Martian soil on itself during the windy days. The wind then carried this earth, sweeping with it part of the dust accumulated on the panels. A washing mechanism had not been embarked on cost reasons, because it would have taken the place of a scientific instrument.
The Insight Probe had arrived in March in November 2018, and had operated in collaboration in particular with the National Center for French 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 soil at the landing site had prevented this “mole” from sinking as expected.
Ultimately buried about 40 centimeters deep, it has nevertheless provided “precious data on the physical and thermal properties of the Martian soil,” said NASA.