NASA is planning more ambitious flights for the Mars Ingenuity helicopter as engineers work on its follow-up back on Earth.

Ingenuity has proven to be far more capable and longer-lasting than called for by its original 30-day mission. The helicopter has flown 66 times and exceeded that original plan by 32 times. Now NASA is at work on its replacement.

Engineers have been testing updated carbon fiber rotor blades which have a different design to Ingenuity's, are more than 10 cm (4 inches) longer and considered to be more robust. Current plans call for helicopter involvement in a Mars sample return mission instead of the "fetch" rover initially envisaged.

During September, engineers spun the blades in the space simulator in NASA's Jet Propulsion Laboratory in Southern California. The cylindrical simulator - with a test diameter of 25ft (7.62 meters) and 85ft (25.9 meters) high - was also where Voyager, Cassini, and Surveyor were tested in a space-like environment, which is also ideal for recreating a Mars-type atmosphere on Earth.

"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."

Almost. While test runs in the simulator are all well and good, the team also has another tool at their disposal - an actual helicopter on actual Mars experiencing what it is like to operate in real Martian conditions.

As such, engineers are pushing the envelope with Ingenuity. Flight 61 set a new altitude record of 24 meters (78.7 feet), and Flight 62 set a speed record of 10 meters per second. However, remote-controlled hot-dogging is only part of the story: Ingenuity was designed to smack into the surface at 1 meters per second (2.2 mph) - a softer landing speed means lighter landing gear could be used. So for flights 57, 58, and 59, controllers demonstrated a landing speed 25 percent slower than what Ingenuity was designed for.

Once the current solar conjunction is out of the way, engineers plan to have Ingenuity undertake a pair of high-speed flights in which a special set of pitch and roll angles will be executed, all in the name of performance measurement.

"Our next-generation Mars helicopter testing has literally had the best of both worlds," said Teddy Tzanetos, Ingenuity's project manager and Mars Sample Recovery Helicopters manager. "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 recreate here on Earth."

Travis Brown, Ingenuity's chief engineer at JPL, noted that in the last nine months, the team has doubled the maximum airspeed and altitude of the helicopter. "On Earth, such testing is usually performed in the first few flights. But that's not where we're flying," he said.

"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." ®

https://www.theregister.com//2023/11/23/ingenuity_pushes_the_envelope/