Researchers at the Faculty of Mechanical Engineering and Naval Architecture (FSB) at the University of Zagreb, in collaboration with the European Space Agency (ESA), are developing an innovative drone designed to transform Mars exploration. This groundbreaking project, titled “Flapping Wing Vehicle for Mars Atmospheric Flight,” aims to create a bio-inspired aerial vehicle that emulates the flight mechanisms of birds and insects, offering enhanced maneuverability and energy efficiency in the thin Martian atmosphere.

The success of this project could mark a significant leap forward in extraterrestrial exploration, providing solutions to the unique aerodynamic and gravitational challenges faced when attempting to fly on Mars. The bio-inspired flight model presents an alternative to conventional rotor-based designs, such as NASA’s Ingenuity helicopter, which faced limitations in the low-density atmosphere of Mars.

Understanding bio-inspired flight

Bio-inspired flight refers to the design of aerial vehicles that mimic the flight mechanisms found in nature, such as the wing movements of birds, bats, and insects. This approach seeks to harness the efficiency and adaptability of natural flyers to overcome challenges in aeronautical engineering. Unlike fixed-wing and rotor-based flight, bio-inspired flight relies on flexible, flapping wings, which allow for:

• Increased lift – Flapping wings can generate more lift relative to their size compared to rigid wings.

• Enhanced maneuverability – The ability to rapidly change wing position and angle allows for quick directional changes and improved agility.

• Energy efficiency – Flapping flight requires less energy to maintain stability and altitude, particularly in low-density environments.

This model is inspired by biological flyers such as the hummingbird and dragonfly, which have perfected efficient flapping wing motion over millions of years of evolution.

The challenge of Martian atmosphere

Mars presents a unique set of challenges for aerial exploration. The Martian atmosphere is approximately 1% as dense as Earth’s, making conventional flight difficult due to reduced aerodynamic lift. The surface gravity on Mars is also lower, about 37% that of Earth’s. These two factors create a complex aerodynamic environment:

• Atmospheric density on Mars – ~0.020 kg/m³ (compared to Earth’s ~1.225 kg/m³)

• Surface gravity on Mars – 3.72076 m/s² (compared to Earth’s 9.80665 m/s²)

In such low-density air, conventional helicopters and fixed-wing aircraft struggle to generate the lift required for stable flight. NASA’s Ingenuity helicopter, which made history as the first powered flight on another planet, relied on ultra-light materials and rapid rotor speeds to compensate for this challenge. However, Ingenuity’s design limits its payload capacity and maneuverability.

Flapping-wing mechanisms offer a solution to this problem by generating higher lift at slower speeds, adapting better to the thin Martian air.

Bio-inspired flight mechanisms

The FSB drone utilizes a flapping-wing mechanism inspired by biological systems on Earth. Unlike traditional rotary-wing designs, such as Ingenuity, which completed 72 successful flights on Mars before experiencing a mechanical failure in January 2024, this drone employs “flapping wing” technology.

Flapping-wing mechanisms work by replicating the dynamic motion of bird and insect wings:

• Lift generation – Flapping creates vortices at the leading edge of the wing, which increases the lift-to-drag ratio.

• Directional control – Flapping wings allow for greater control over thrust and direction compared to fixed-wing or rotor designs.

• Hovering and low-speed flight – Flapping wings can hover and maintain stability at low speeds, even in low-density environments.

The FSB design is influenced by the concept of an entomopter—an aircraft that mimics insect flight using flapping-wing aerodynamics. This design offers significant advantages over conventional flight models:

“An entomopter is capable of achieving high lift with rapidly flapping wings, allowing the fuselage to move slowly relative to the ground, which is ideal for the thin Martian atmosphere.”

The entomopter model has been explored for decades, but recent advancements in lightweight materials, microelectronics, and autonomous flight control systems have made it a feasible solution for Mars exploration.

Collaborative efforts and testing

The FSB drone project is a collaborative effort involving several prestigious European institutions, including TU Delft and Politecnico di Milano. The drone is being constructed at the University of Zagreb, after which it will undergo rigorous testing at ESA’s laboratory in the Netherlands.

Testing will take place in a specialized Mars chamber that accurately simulates the thin atmosphere and gravity of Mars. This controlled environment allows researchers to:

• Fine-tune the wing flapping motion.

• Optimize flight stability and control systems.

• Test energy consumption and battery life under simulated Martian conditions.

The project aims to demonstrate sustained and controlled flight, which would be a major leap forward from the short, low-altitude flights achieved by Ingenuity.

Similar projects and technological advancements

Other bio-inspired flight projects have also explored flapping-wing flight for Mars exploration:

• Marsbee Project – This NASA-funded initiative envisions a swarm of flapping-wing micro-robots designed to fly in the Martian atmosphere, providing high-resolution surface mapping and environmental monitoring.

• DelFly Project – Developed by TU Delft, this biomimetic micro-air vehicle mimics the flight of dragonflies and is capable of high maneuverability in low-density air.

The FSB drone distinguishes itself through its larger scale and increased payload capacity, making it suitable for scientific instruments and environmental sensors.

Implications for future Mars missions

The development of bio-inspired drones represents a significant advancement in planetary exploration technology. By emulating the efficient flight mechanisms of birds and insects, these drones can:

• Provide more comprehensive aerial mapping of Martian terrain.

• Collect environmental data from hard-to-reach areas.

• Improve the ability to study atmospheric patterns and weather.

This innovation not only enhances our ability to explore Mars but also contributes to the broader field of bio-inspired engineering, demonstrating the potential of nature-inspired solutions in addressing complex technological challenges.

Conclusion

The integration of bio-inspired flight mechanisms into drone technology marks a pivotal shift in our approach to extraterrestrial exploration. By overcoming the limitations of conventional flight in the thin Martian atmosphere, bio-inspired drones hold the potential to unlock new frontiers in Mars exploration. The ongoing research and development at FSB and ESA represent a promising step toward more efficient, adaptable, and capable exploration tools—bringing us closer to unraveling the mysteries of Mars and beyond.