On May 24 ESA announced end of the investigation, which continued since anomaly and crash of the Schiaparelli EDM on Mars surface on October 19, 2016. Lander was destroyed after it hit into Mars surface after seven months of space journey, which started on March 14, 2017.
During attempt of controlled reentry and landing EDM lander created by Thales Alenia Space and being result of cooperation between ESA and Roscosmos was totally destroyed. EDM failed to reduce its speed and after series of problems it smashed into Meridiani Planum with speed of 540 km/h instead 10 km/h.
Until now ESA was conducting investigation to evaluate how it was possible that EDM suffered for problems during such crucial phase of flight. To remind ESA discovered in following weeks after crash, that EDM was unable to evaluate correctly its altitude.
Released on May 24 summary of the report from investigation points describes precisely reasons of anomaly. Schiaparelli EDM IMU (Inertial Measurement Unit) failed to operate when EDM rotated much more faster than it was predicted. It caused, that onboard computer evaluated that EDM is reversed upside down what along with incorrect data from radar altimeter has led to the recognition that EDM is below sea level. Drag parachute and rocket retro thrusters were working correctly but most crucial part of the system failed.
Summary points out following reasons of issues with lander.
- Simplified modeling of the parachute’s dynamics, caused that engineers did not predict that EDM will rotate with high velocity
- Problems with IMU’s saturation measurement and its relation with guidance, navigation and control system of the lander
- Failure Detection, Isolation and Recovery along with design robustness were not sufficient
- Problems with coordination and control over subcontractors
David Parker, ESA’s director of human spaceflight and robotic exploration said in the official statement: “There were clearly a number of areas that should have been given more attention in the preparation, validation and verification of the entry, descent and landing system... We will take the lessons learned with us as we continue to prepare for the ExoMars 2020 rover and surface platform mission. Landing on Mars is an unforgiving challenge but one that we must meet to achieve our ultimate goals.”
ESA plans another ExoMars mission for 2020. In this mission ESA will send to Mars lander and robotic rover to perform series of scientific experiments.