NASA’s 1.8-kilogram Ingenuity helicopter flew through Martian air roughly 100 times thinner than Earth’s—its counter-rotating blades spun at about 2,400 revolutions per minute, nearly five times faste

Ingenuity's 2,400-rpm rotors were one part of a complete system built to generate lift in an atmosphere less than one per cent as dense as Earth's—and to survive long enough to do it 72 times. On Earth, a 1.8-kilogram helicopter would be a small machine. On Mars, NASA’s Ingenuity had to become something stranger: an ultralight aircraft whose two rotors spun in opposite directions at around 2,400 revolutions per minute, sweeping through air... [11912 chars]