By BlueShift | 2024-12-12

Engineers from NASA's Jet Propulsion Laboratory (JPL) and AeroVironment are preparing a detailed assessment of the Ingenuity Mars Helicopter's final flight January 18.

The detailed assessment will be published in the coming weeks as a NASA technical report, the agency announced December 11.

Launched July 30, 2020, Ingenuity was designed as a technology demonstration to perform up to five experimental test flights over 30 days. It landed on Mars February 18, 2021, and outperformed expectations.

"It operated for almost three years, performed 72 flights and flew more than 30 times farther than planned while accumulating over two hours of flight time," NASA said in a statement.

Ingenuity was the first aircraft to fly on another world -- and its final flight and crash-landing are the subject of the first aircraft accident investigation on another world.

The inability of Ingenuity's navigation system to provide accurate data during its final flight likely caused a fatal chain of events, the investigation concluded.

The helicopter's vision navigation system was designed to track visual features on the surface using a downward-looking camera over well-textured (pebbly), flat terrain.

That system was more than sufficient for Ingenuity's planned first five test flights, NASA said. But by Flight 72, the helicopter was in a region of Jezero Crater filled with steep, relatively featureless sand ripples.

"When running an accident investigation from 100 million miles away, you don't have any black boxes or eyewitnesses," said Håvard Grip, chief pilot for the first half of Ingenuity's mission at JPL, in the December 11 statement.

"While multiple scenarios are viable with the available data, we have one we believe is most likely: lack of surface texture gave the navigation system too little information to work with."

Data recorded during Flight 72 show that about 20 seconds after takeoff, the navigation system could not find enough surface features to track.

"Photographs taken after the flight indicate the navigation errors created high horizontal velocities at touchdown," NASA said in the statement. "In the most likely scenario, the hard impact on the sand ripple's slope caused Ingenuity to pitch and roll."

The rapid attitude change resulted in loads on the fast-rotating rotor blades beyond their design limits, snapping all four of them off about a third of the way from the tip.

"The damaged blades caused excessive vibration in the rotor system, ripping the remainder of one blade from its root and generating an excessive power demand that resulted in loss of communications," according to NASA.

'Alive and well'

While Flight 72 permanently grounded Ingenuity, the helicopter has continued to provide useful information to NASA scientists on Earth.

"Ingenuity, aside from the rotor system, is still alive and well," said Teddy Tzanetos, Ingenuity's project manager at JPL, during the team's December 11 presentation at the American Geophysical Union annual meeting in Washington, DC.

"Even after the hard landing on Flight 72, avionics, battery, sensors have all been functional," he said. "And she still has one final gift for us, which is that she's now going to continue on as a weather station of sorts, recording telemetry, taking images every single sol [a solar day on Mars] and storing them on board."

Based on the amount of flash memory available, Ingenuity could play this role for up to 20 years.

"We're now approaching four years of continuous operations, suggesting that not everything needs to be bigger, heavier and radiation-hardened to work in the harsh Martian environment," Tzanetos said in the NASA statement.

Future Mars helicopters

Inspired by Ingenuity's longevity, NASA engineers have been testing smaller, lighter avionics that could be used in vehicle designs for the Mars Sample Return campaign.

The data are also helping engineers as they research future Mars helicopters.

Tzanetos shared details on the Mars Chopper rotorcraft, a concept that he and other Ingenuity alumni are researching.

As designed, Chopper is approximately 20 times heavier than Ingenuity, according to NASA.

It could fly several kilograms of science equipment and autonomously explore remote Martian locations while traveling up to 3km in a day.

In comparison, Ingenuity's longest flight was 704 meters.

"Ingenuity has given us the confidence and data to envision the future of flight at Mars," said Tzanetos, according to JPL.