
As reported, NASA is investigating the cause of the Jan. 18, 2024, accident of the Ingenuity Mars Helicopter.
“When running an accident investigation from 100 million miles away, you don’t have any black boxes or eyewitnesses,” said Ingenuity’s first pilot. Håvard Grip of NASA’s Jet Propulsion Laboratory (JPL). “While multiple scenarios are viable with the available data, we have one we believe is most likely: Lack of surface texture gave the navigation system too little information to work with.”
To me, that sounds a lot like flat light.
From the FAA, “Flat light is an optical illusion, also known as ‘sector or partial white out.’ It is not as severe as ‘white out’ but the condition causes pilots to lose their depth-of-field and contrast in vision. Flat light conditions are usually accompanied by overcast skies inhibiting any good visual clues. Such conditions can occur anywhere in the world, primarily in snow-covered areas but can occur in dust, sand, mud flats, or on glassy water. Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates. As a result of this reflected light, it can give pilots the illusion of ascending or descending when actually flying level. However, with good judgment and proper training and planning, it is possible to safely operate an aircraft in flat light conditions.”
Hopefully NASA’s next Martian rotorcraft, Chopper, will learn from Ingenuity.