Investigation: ESA Mars lander crashed due to incorrect height estimate

The Schiaparelli-Mars lander crashed on Mars due to a software error that caused the lander to think it had already landed, after which it crashed to the surface at a speed of 540 kilometers per hour. This is shown by independent research.

The conclusion of it research is that after opening the parachute, the lander made unreliable estimates of the height of the lander above the surface due to strong spinning and tilting. At one point, the computer even calculated that the lander had landed below the surface of Mars when it was actually at an altitude of 3.7 kilometers. Therefore, the lander released its parachute and aft heat shield too early and fired the thrusters for 3 counts instead of the standard 30 counts. As a result, the lander then impacted Mars at a speed of 150 meters per second.

The Shiaparelli Mars lander was due to land on the planet’s surface in October of 2016. However, when the vehicle landed, there was no contact with it, so it was not immediately possible to estimate whether the lander had made a ‘clean’ landing or had crashed. After the landing attempt, the batteries in the lander have enough energy to keep the module alive for three to ten days, during which the ESA has a chance to re-establish communication with the lander. However, this did not happen. Subsequently, the ESA was able to deduce from satellite photos before and after the landing attempt that the Mars lander had crashed. The research results are in line with what the ESA already suspected was the cause.

The investigation was conducted by the so-called Schiaparelli Inquiry Board, an independent research panel that is also responsible for making recommendations about the future of the European Space Agency’s Mars missions. The substantive technical proposals have been included in the research findings. The Mars mission will continue as usual, as was already decided in December by the member states of the European Space Agency. 436 million euros is required to continue the mission. In total, the mission will cost 1.3 billion euros.

The ESA draws However, the crash also has a bright side. Indeed, it has exposed deficiencies in hardware, software and models of parachute behavior that can be corrected in the next phase of the ExoMars mission. This phase was also primarily intended to fine-tune the technology behind the landing so that the moving ExoMars rover can begin its mission to find traces of life, past or present, in 2020.

On the left the landing site for the landing. Right after landing, with a white dot below and a black spot above.
The white dot is probably the parachute, the black spot the place where Schiaparelli hit.