Better rotors, higher heights thanks to NASA's dual-planet presence

Better rotors, higher heights thanks to NASA's dual-planet presence
An artist's rendering of the Ingenuity Mars Helicopter on the Red Planet's surface
An artist's rendering of the Ingenuity Mars Helicopter on the Red Planet's surface
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An artist's rendering of the Ingenuity Mars Helicopter on the Red Planet's surface
An artist's rendering of the Ingenuity Mars Helicopter on the Red Planet's surface

There aren't any organizations other than NASA that can claim they are operating on two different planets (at least none we know of from here on Earth). The space agency is now using that reach to create better helicopter blades on Earth and to push the Ingenuity Helicopter to greater heights on Mars.

"Our next-generation Mars helicopter testing has literally had the best of both worlds," said Teddy Tzanetos, Ingenuity Mars Helicopter's project manager and manager for the Mars Sample Recovery Helicopters. "Here on Earth, you have all the instrumentation and hands-on immediacy you could hope for while testing new aircraft components. On Mars, you have the real off-world conditions you could never truly re-create here on Earth."

Since Ingenuity became the machine that embarked upon the first powered flight on another planet in April 2021, it has been exceeding expectations. It set an altitude record by soaring 46 ft (14 m) above the Martian surface in late 2022, and in April of this year, it marked its 50th flight by breaking that record with a height of 59 ft (18 m).

NASA has just announced that to date, it's now flown 66 times, which is mind-boggling, considering that engineers only expected it to achieve five flights. It's also reached heights of 78.7 ft (24 meters) and broken a speed record, by topping out at 22.3 mph (10 meters per second).

To push Ingenuity to these levels of performance NASA has been toying with the instructions they send the craft before each flight. The higher altitude has allowed the craft to "see" more of the landscape below it, which allows it to not get confused by the ground racing by it, which has been an issue with increasing its speed in the past.

The tests on Mars have not only resulted in the faster and higher metrics, but they've also led to 25% slower landing speeds, which could lead to lighter landing gear on future Martian helicopters. Basically, NASA engineers are using the Martian landscape and the planet's thin atmosphere as a lab to learn as much as they can about how motorized flying vehicles operate in real off-Earth conditions.

"Over the past nine months, we have doubled our max airspeed and altitude, increased our rate of vertical and horizontal acceleration, and even learned to land slower," said Travis Brown, Ingenuity's chief engineer at JPL. "The envelope expansion provides invaluable data that can be used by mission designers for future Mars helicopters."

You can watch Ingenuity make one of its high-altitude flights in the video below.

Two Views of a High-Altitude Flight for Ingenuity Mars Helicopter

Earth assist

Along with dialing in the achievements Ingenuity is capable of, NASA has been simultaneously working on developing better helicopter rotors here on Earth at the Jet Propulsion Lab's space simulator, a space that measures 25-feet wide and 85-feet tall (8 x 26 meters). Here engineers have been running tests on carbon-fiber rotor blades that are four inches longer than Ingenuity's, which could lead to bigger, more robust helicopters for future Mars missions. The testing has helped the research team overcome the vibration-causing turbulence that can be problematic from larger rotors at higher speeds.

"We spun our blades up to 3,500 rpm, which is 750 revolutions per minute faster than the Ingenuity blades have gone," said Tyler Del Sesto, Sample Recovery Helicopter deputy test conductor at JPL. "These more efficient blades are now more than a hypothetical exercise. They are ready to fly." And they're ready to do so at the near-hypersonic speed of 0.95 Mach.

The following video offers a look at the rotor testing.

Testing Next-Generation Mars Helicopter Rotors

The team plans to continue research work on both planets to improve any future copters sent to Mars. For example, in December, Ingenuity will embark upon two more high-speed tests in which it will move through new pitch-and-roll angles intended to measure its performance even more, although the team is being cautious about just how far the copter can be pushed.

"You have to be a little more careful when you're operating that far away from the nearest repair shop, because you don't get any do-overs," said Brown.

Source: NASA

The Ingenuity aircraft has cyclic pitch control on a coaxial rotor system. This requires an extremely complex hub. Both mechanically and electronically. Which means higher risk of damage and/or failure. Wonder what has made the creators to abandon the rugged quadcopter concept in their choice?
Improving efficiency of manned helicopter rotors is fairly easy, a cost / downside may be the ability to autorotate, this is not generally a concern for unmanned/uninhabited aircraft...

Improved variable geometry / aeroelasticity is a direction to chase... ( not to negate the intricacies of; variable camber, altering tip-to-root twist, realtime dynamic airflow/circulation control, etc)