On April 19, NASA announced that the Ingenuity Mars Helicopter achieved a successful first test flight from the surface of Mars — making it the first aircraft in history to make a powered, controlled flight on another planet. In its initial autonomous flight, the helicopter achieved a maximum altitude of 10 ft (3 m) and maintained a stable hover for 30 seconds, completed a turn, and then landed.
“Now, 117 years after the Wright brothers succeeded in making the first flight on our planet, NASA’s Ingenuity helicopter has succeeded in performing this amazing feat on another world,” said Thomas Zurbuchen, associate administrator for Science at NASA. “While these two iconic moments in aviation history may be separated by time and 173 million miles of space, they now will forever be linked. As an homage to the two innovative bicycle makers from Dayton, this first of many airfields on other worlds will now be known as Wright Brothers Field, in recognition of the ingenuity and innovation that continue to propel exploration.”
As part of the Mars 2020 Perseverance rover mission, the Ingenuity helicopter will support NASA’s efforts to achieve the next step of its high-priority science goals for Mars exploration. In particular, the helicopter is intended to demonstrate whether future exploration of the Red Planet could include an aerial perspective. Aluminum and light materials play a key role in the design of many critical structures and components of the helicopter, along with the Perseverance mission’s rockets and rover.
Flying on Mars
Designing a helicopter for flight on Mars comes with a number of challenges and unknowns due to the planet’s significantly lower gravity (one-third that of Earth) and its extremely thin atmosphere (having only 1% the pressure at the surface compared to Earth). According to NASA, this means that there are relatively few air molecules for the two 4 ft (1.2 m) wide rotor blades to interact with in order to achieve flight.
In addition, Mars has freezing temperatures, with nights as cold as minus 130°F (-90°C) at the Jezero Crater. This pushed the design limits of the helicopters components and systems, which had to be designed to withstand and continue to operate in such extreme conditions.
The Ingenuity helicopter had to be specifically designed in order to overcome these challenges. Weighing in at no more than 4 pounds (1.8 kilograms), the helicopter is comprised of more than 1,500 individual pieces of carbon fiber, flight-grade aluminum, silicon, copper, foil and foam.
Attached to an aluminum plate on the Perseverance rover’s belly, the Ingenuity helicopter hitched a ride until the rover reached a suitable “airfield” location, where it was deployed for its flight tests.
Landing on Mars
Since its first flight, the Ingenuity has successfully conducted several additional test flights over the Martian surface, achieving incrementally farther distance and greater altitude. With the repeated flights comes the need to manage repeated rough landings on the rocky landscape — making the helicopter’s landing gear as equally important as its aerodynamics.
Constructed of titanium and aluminum, the suspension system designed into the Ingenuity’s legs is able to provide a cushy landing. The suspension features a distinctive open hoop structure at each corner of the fuselage where the landing legs attach. The upper half of the suspension is comprised of a soft non-alloyed aluminum flexure that serves as the damper or “shock absorber,” while the lower half of this hoop is a titanium spring that can bend up to 17 degrees to provide 3.5 inches of motion in the suspension.
“By plastically deforming and fatiguing as it absorbs energy, this flexure acts much like the crumple zone structure of a car chassis,” noted J. (Bob) Balaram, the Ingenuity helicopter chief engineer, and Jeremy Tyler, senior aero/mechanical engineer for the Mars Helicopter Project at AeroVironment. “However, unlike a car or the crumple-cushioned landing gear of the Apollo moon landers, Ingenuity’s titanium springs rebound after each impact to pull these aluminum dampers back into shape for the next landing.”