NASA is preparing the next generation of Mars helicopters. Engineers are working on blades that will allow the craft to fly higher and farther than current vehicles while carrying scientific instruments. The results were published in the journal AIAA Journal.
The first helicopter, Ingenuity, has already made history as the first powered craft to rise into the sky of another planet. The SkyFall mission, scheduled for launch in 2028, will continue this line: three helicopters will be sent to Mars at once. Both missions use a blade with a curved edge, adapted to the thin Martian atmosphere.
However, researchers are looking further ahead. They are studying thinner and sharper designs so that craft after SkyFall can travel far beyond the limits available today. A team from NASA's Ames Research Center in Silicon Valley, together with Imperial College London and Nagoya University, tested a new blade profile - the cross-sectional shape that determines how air flows around the blade.
The new profile is called roamx-0201. It was created using computer simulations and algorithms tuned to Martian conditions, resulting in a thinner asymmetric shape. Wind tunnel tests showed that the optimized design increases efficiency and recovers better in risky flight regimes.
Using precise simulations, the scientists compared roamx-0201 with Ingenuity's capabilities. They found that the new blades can increase the distance a helicopter flies without landing from 0.7 kilometers (0.43 miles) for Ingenuity to 18.7 kilometers (11.6 miles), provided scientific instruments are on board. The results were made public in an article published on September 22 in AIAA Journal.
The success is partly explained by the fact that the profile operates at high speeds longer before so-called wave drag occurs - a phenomenon in which performance drops sharply when the rotor approaches the speed of sound. On Mars, the speed of sound is lower than on Earth, so this barrier is reached earlier.
There is another difference from previous designs. When air flows around the blade, a thin boundary layer forms at its surface. The new profile deliberately disrupts the flow of this layer right at the leading edge. A disturbance arises that, strangely enough, pulls the blade upward and helps generate lift more efficiently than before.
Another problem for helicopters is flow separation: an aerodynamic state in which performance drops sharply and flight becomes unstable after a change in the angle of the oncoming flow. Ingenuity's blades lost efficiency very quickly under such conditions, while roamx-0201 showed noticeably better behavior during separation in the regimes studied. This means that future helicopters will be able to fly safely across a wider range of angles.
The technology is not yet ready to be sent to Mars. However, the tests help engineers understand and eliminate discrepancies between computer predictions and real performance. NASA's research is aimed at creating more efficient Mars helicopters that can fly farther, carry more payload and open up new scientific opportunities.