Eleven months after the Ingenuity helicopter made its final flight on Mars, engineers and scientists at NASA and a private company that helped build the flying vehicle said they have identified what probably caused it to crash on the surface of Mars. In short, the helicopter's on-board navigation sensors were unable to discern enough features in the relatively smooth surface of Mars to determine its position, so when it touched down, it did so moving horizontally. This caused the vehicle to tumb...