The board of inquiry's investigation revealed that at the time that the lander deployed its parachute it began spinning unexpectedly fast. This superfast rotation briefly saturated Schiaparelli spin-measuring instrument, which resulted in a large attitude-estimation error by the guidance, navigation and control-system software. This resulted in the computer calculating that it was below ground level, triggering the early release of the parachute and backshell, a brief firing of the thrusters for only 3 seconds instead of 30 seconds, and the activation of the on-ground system as if Schiaparelli had landed. The inquiry also determined that "[t]he mission would not have been jeopardised by the attitude knowledge error induced by IMU [Inertial Measurement Unit] saturation, if the persistence time would have been set at a lower value."
