NASA’s Ingenuity Mars helicopter crashed early this year due to a navigation system error caused by the featureless terrain it was flying over. The helicopter’s project engineers concluded that the root cause of the crash was degraded navigation, likely due to visually bland terrain and high local slopes.
During its 72nd and final flight in January, the helicopter used a downward-facing camera to track features on the surface, which worked well for most of the mission when flying over rocky terrain. However, when it reached an area with sand ripples that provided few features for the navigation system to lock onto, the system began to struggle.
The helicopter touched down with a horizontal velocity of about 2.5 meters per second, five times what it was designed for, but suffered minimal damage. The rotors may have broken during the hard landing, causing them to bend and break off about one-third of the way from the tip.
However, further analysis suggests that the blades were damaged by bending loads upon landing, rather than contact with the surface. This conclusion is supported by structural analysis of the blades, which indicate that they broke at a weak structural point along the blade due to similar loads.
The investigation led to recommendations for improving navigation systems and robust handling of telemetry in the event of anomalies. The experience gained from Ingenuity will support potential future Mars helicopters, including a concept called Mars Chopper that could carry more payload and fly faster than rovers.
Despite the hard landing, Ingenuity remains operational, serving as a weather station and collecting data daily. It is still in contact with Perseverance, the rover that relayed data to Earth, although their communication may be cut off within the next month due to changing terrain features.
Source: https://spacenews.com/jpl-completes-investigation-of-ingenuitys-final-flight