A machine weighing 1.8 kilograms pulled off the aerodynamic equivalent of flying a helicopter at 87,000 feet on Earth. This episode tells the full biography of NASA’s Ingenuity Mars helicopter, beginning with its three years as an unfunded rebel project at the Jet Propulsion Lab, the opposition from Mars 2020 chief scientist Kenneth Farley, and the $23 million finally secured in the 2018 federal budget. It then digs into the engineering required to fly in an atmosphere with one percent of Earth’s density: four-foot coaxial rotors spinning at 2,400 to 2,900 RPM, a smartphone Snapdragon processor running Linux, off-the-shelf Sony batteries, and a test chamber with a wall of nearly 900 computer cooling fans and a gravity-offload string.

The story covers the watchdog timer glitch that nearly derailed the first flight, the 85 percent workaround the team gambled on, and the 40-second flight on April 19, 2021 that earned the site the airport code JZRO, Wright Brothers Field. Ingenuity then evolved from a 30-day demo into a scout for the Perseverance rover, surviving winter brownouts, a dead inclination sensor that engineers replaced with clever IMU software, and a 63-day radio blackout. The episode ends with the 72nd flight over the featureless Valinor Hills, where optical navigation lost its bearings and all four rotor blades snapped, and with the helicopter’s new life as a stationary weather station.

• Why a slow radiation-hardened space chip could never keep a helicopter stable
• How a scrap of fabric from the 1903 Wright Flyer rode along under the solar panel
• Why the motors heated one degree Celsius per second in flight while nights hit minus 130 Fahrenheit
• How engineers taught the helicopter to feel gravity with its inertial measurement unit
• What the sand dune crash taught planners about the next generation of Mars rotorcraft