A new rotor airfoil out of NASA Ames did something counterintuitive — it got thinner and sharper — and in simulation it stretched a single Mars flight from 0.7 kilometers to as much as 18.7. Ingenuity was never supposed to last. NASA's helicopter arrived on Mars in 2021 as a technology demonstration, planned for up to five flights. It flew 72 times before rotor damage ended its mission in January 2024 — and every serious Mars plan since has had to answer the question of what