According to the landing sequence... http://www.popularmechanics.com/space/a23475/beagle-2-schiaparelli/?zoomable http://www.popularmechanics.com/space/a23475/

According to the landing sequence... http://www.popularmechanics.com/space/a23475/beagle-2-schiaparelli/?zoomable http://www.popularmechanics.com/space/a23475/beagle-2-schiap... ...the lander was supposed to detach from the aeroshell at about 1km up. So if it fell from 2 to 4km up, that implies that it detached too early. This article: https://spaceflightnow.com/2016/10/20/last-data-from-schiaparelli-mars-lander-hold-clues-to-what-went-wrong/ https://spaceflightnow.com/2016/10/20/last-data-from-schiapa... ...says that the telemetry shows that the engines did fire, for at least a few seconds. My uninformed hypothesis: the lander detached early for some reason, and started falling. As it approached the ground, the radar saw the ground coming, and it fired the engines for the final braking. But because it had been falling so far, it was now going too fast for the engines to stop it in time, and it hit the ground hard. (Mars doesn't really do terminal velocities.) It says they have 600MB of telemetry. That's quite impressive.