This side-by-side image shows the robotic helicopter Ingenuity, as seen from the Mars Perseverance rover, on the ground (left) and then up in the air (right).
Credit: NASA/JPL

Some 117 years after the first powered airplane flight by the Wright brothers, humanity has achieved another first-flight milestone. Early Monday morning, April 19, a robotic helicopter called Ingenuity successfully lifted off from Mars, hovered 10 feet (3 meters) off the ground for about 40 seconds, and then made a controlled landing.

Ingenuity is part of the United States National Aeronautics and Space Administration (NASA) mission Mars 2020. The main part of the mission is the large six-wheeled rover called Perseverance. The purpose of the mission is to search for signs of past life on Mars and to perform several experiments.

Ingenuity was carried to the surface of Mars on the belly of Perseverance, which landed on Feb. 18, 2021. The rover dropped Ingenuity on the Martian surface and drove away to observe the flight from a safe distance. After a week-long delay to enable engineers to fix a software problem, the drone conducted its first flight Monday morning.

The force of gravity on Mars is only about 38 percent that on Earth. This fact makes getting off the ground slightly easier. However, this advantage is offset by Mars’s wispy atmosphere. Flight requires a force called lift, which is generated by moving a specially shaped wing surface (in this case, a pair of rotors) through the air. However, the atmosphere of Mars is just one percent as thick as the atmosphere of Earth, making it more difficult to generate lift. Ingenuity has to spin its rotors at 2,500 revolutions per minute to get off the ground, far faster than does a helicopter or drone rotorcraft on Earth.

Additionally, radio signals take minutes to travel between Earth and Mars. So mission controllers on Earth cannot control the craft in real time. Rather, Ingenuity has to be completely autonomous (self-piloting) during its flights.

Ingenuity will conduct several more flights of increasing length and complexity in the coming weeks. It holds no scientific instruments itself, but it will use the flights to collect more information about flying on Mars.

Ingenuity is paving the way for the next generation of Mars flyers. But the next flying probes might not use rotors—and there might be dozens of them. The engineer Chang-kwon Kang is developing a proposal to send to the Red Planet a swarm of butterfly-sized drones that fly by flapping their wings. You can read all about it in the book Mars-Exploring Flying Swarm, part of the “Out of This World” series developed by World Book and NASA’s Innovative and Advanced Concepts (NIAC) program.