PARIS — The European Space Agency (ESA) on Nov. 23 said its Schiaparelli lander’s crash landing on Mars on Oct. 19 followed an unexplained saturation of its inertial measurement unit (IMU), which delivered bad data to the lander’s computer and forced a premature release of its parachute.
Polluted by the IMU data, the lander’s computer apparently thought it had either already landed or was just about to land. The parachute system was released, the braking thrusters were fired only briefly and the on-ground systems were activated.
Instead of being on the ground, Schiaparelli was still 2.3 miles (3.7 kilometers) above the Mars surface. It crashed, but not before delivering what ESA officials say is a wealth of data on entry into the Mars atmosphere, the functioning and release of the heat shield and the deployment of the parachute — all of which went according to plan. …