'It's sort of been invincible until this moment:' Mars helicopter Ingenuity pilot says 'bland' terrain may have doomed NASA chopper 

 Flat, featureless terrain likely caused the accident that has permanently grounded NASA's Mars helicopter Ingenuity, mission team members say. 

https://cdn.mos.cms.futurecdn.net/CVF6bnw6jfC2cEFtDfWpod.jpg

https://www.space.com/ingenuity-mars-helicopter-doomed-bland-terrain