New helicopter rotor could improve future Mars exploration missions

Researchers from Imperial College London, working with collaborators at NASA Ames Research Center, Tohoku University and Nagoya University, have evaluated a new rotor airfoil that could improve the performance of future Mars helicopters.

A new international study has shown that a rotor airfoil designed specifically for the Martian atmosphere could significantly outperform the airfoil flown on NASA’s Ingenuity helicopter, paving the way for more ambitious Mars missions.

The research, published in AIAA Journal, compared the CLF‑5605 airfoil used on Ingenuity with an optimised design called roamx‑0201, developed by the ROAMX team at NASA Ames Research Center. After testing both airfoils under Mars‑like conditions, the new roamx‑0201 airfoil consistently delivered better aerodynamic performance, suggesting that future Mars helicopters could fly further and carry heavier weights than is currently possible.

Professor Oliver Buxton, Professor of Fluid Mechanics at Imperial’s Department of Aeronautics, said: “We’re proud to have collaborated internationally with the ROAMX team at NASA and the experimental team at Nagoya (previously Tohoku) to demonstrate the superior performance of this new airfoil. Hopefully this will see some action on the red planet before too long!”

Putting a Mars-optimised airfoil to the test 
Designing aircraft for Mars presents a unique engineering challenge. The Martian atmosphere has a much lower density and pressure (around 1% of Earth’s) and a carbon dioxide‑rich composition, meaning helicopter rotors must generate lift in conditions unlike those encountered by conventional aircraft.

Unlike CLF‑5605, which is a conventional airfoil adapted for use on Ingenuity, roamx‑0201 has been designed from the outset for the Martian atmosphere. Under these conditions, air flow is pushed into an unusual aerodynamic regime: the Reynolds number is low, similar to the flow over a dragonfly’s wing on Earth, while the Mach number is relatively high (in the transonic range), meaning that parts of the flow approach the speed of sound.

To test how the new roamx‑0201 airfoil would perform, the research team combined advanced computer simulations with physical experiments in the Mars Wind Tunnel at Tohoku University, one of the few facilities in the world capable of recreating key conditions of the Martian atmosphere.

They compared the two airfoils across a range of operating conditions and found that roamx-0201 consistently outperformed the Ingenuity design. The new airfoil achieved up to a 43% improvement in aerodynamic efficiency and was capable of generating greater lift while maintaining performance at higher operating angles.

We’re proud to have collaborated internationally with the ROAMX team at NASA and the experimental team at Nagoya to demonstrate the superior performance of this new airfoil. Oliver Buxton Professor of Fluid Mechanics

Unlocking new possibilities in future Mars missions 
The improved aerodynamics of the roamx‑0201 airfoil translate into more capable rotors, enabling Mars helicopters to travel greater distances, carry a larger payload and even explore regions that have previously been difficult to reach, such as cliffs and deep craters.

The study brings the next generation of Mars rotorcraft a step closer, with the potential to explore regions of Mars that have never been seen up close before.

The study and associated research publication was a collaboration between NASA Ames Research Center in the USA, Imperial College London, Tohoku University and Nagoya University in Japan. The team at Imperial were Professor Oliver Buxton, Dr Peter Vincent (alum) and Dr Lidia Caros Roca (alum).