Last year, in October, the European Space Agency or ESA was looking forward to its ExoMars Schiaparelli lander arriving on Mars. Instead, its spacecraft crashed into the planet, which also led to its losing contact with the mission team.
After the NASA Mars Reconnaissance Orbiter helped find Schiaparelli’s landing site, scientists started investing its crash. Now, they believe to have determined the reason behind its un-wished for faith, namely, a computer glitch.
Computer Glitch Led to the Untimely End of the Schiaparelli Lander?
An ESA inquiry board has been in charge of determining the reason behind the crash landing of the unnamed mission lander. Initial observations suggested that this failed to release its parachutes at the proper moment.
According to the recently released report, the extreme descent through Mars’s atmosphere was the most likely cause of a computer glitch. Such an issue was detected when analyzing the IMU or Inertial Measurement Unit. This was designed to measure the lander’s inertial velocity, fed to Schiaparelli’s guidance computer, as it helps it operate.
But this time around, the IMU seems to have offered “bad data”. This confused the spacecraft into believing that it was already on Mars or at least closer to it than it actually was. Because of this, the system did not fire up its braking thrusters for as long as it should. In turn, this caused the lander, which was still some 3.7 km above the planet, to crash into the Martian surface at a speed of around 150 m/s.
The ESA inquiry board was also very interested in determining the cause of this computer glitch. An internal malfunction was rapidly ruled out. Instead, the board reports that:
“The high dynamic phenomenon experienced […] due to a natural phenomenon caused by a combination of various parameters, which were not properly predicted/expected before flight.”
This does not point out a human or system error. Instead, according to the report, it shows that the lander had to face more severe than expected conditions as it was landing on the planet. Ones that the IMU couldn’t deal with and which scientists had not predicted.
Scientists will probably continue analyzing this report as they are looking to develop and avoid the same type of problems on the ExoMars 2020 lander.
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