It appears the bland Martian surface triggered a chain of events that left NASA’s Ingenuity helicopter permanently grounded on the red planet.
The helicopter’s flying career came to an abrupt end earlier this year when Flight 72 was cut short, and communications were briefly lost. After re-establishing contact, it soon became clear Ingenuity would not be flying again – the rotor blades were damaged, and one was entirely detached.
At the time, the prevailing theory was that the flight ended when Ingenuity’s downward-facing camera could not pick out features on the surface. According to the NASA Jet Propulsion Laboratory (JPL), this is still the most likely scenario for what started a chain of events that left the helicopter crippled.
Performing an air crash investigation from hundreds of millions of kilometers away is tricky. It’s impossible to get hands on the wreckage, there are unlikely to be any witnesses, and there aren’t brightly colored black boxes to give clues about what happened in the final minutes of the flight.
What there is, however, is telemetry. Data sent during the final flight indicates that around 20 seconds after take-off, Ingenuity’s navigation system couldn’t find enough surface features to track. It was designed to operate over textured, flat terrain, not the steep, featureless sand ripples where it ultimately met its demise.
“Photographs taken after the flight indicate the navigation errors created high horizontal velocities at touchdown,” according to JPL. Engineers reckon the most likely scenario is that Ingenuity made a hard landing on the slope of a sand ripple. The sudden pitch and roll exerted stress on the rotor blades past their design limits, and all four snapped at their weakest point. The damage caused vibration in the rotor system, which ripped off one blade entirely.
The team lost communications due to the excessive power demand.
Ingenuity’s impressively extended mission is a testament to how far engineers can push the envelope. It was only designed for five flights, but the helicopter was on flight 72 when the accident happened.
It is a remarkable feat of engineering, considering the helicopter was built to be affordable and use off-the-shelf components where possible.
“We became the first mission to fly commercial off-the-shelf cellphone processors in deep space,” said Teddy Tzanetos, Ingenuity’s project manager. “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.”
In happier times: NASA’s Ingenuity Mars ‘copter seen hovering during its third flight back in April 25, 2021 … as seen by the left Navigation Camera aboard the Perseverance Mars rover – Image: NASA/JPL-Caltech
While the helicopter will never fly again, it has continued to transmit weather and avionics test data to the Perseverance rover on a weekly basis.
Engineers are working on follow-ups to Ingenuity. During the American Geophysical Union’s annual meeting, Tzanetos shared details on the Mars Chopper rotorcraft, which would be approximately 20 times heavier than Ingenuity and could fly science equipment over Mars, traveling autonomously for up to two miles in a day.
Tzanetos said: “Ingenuity has given us the confidence and data to envision the future of flight at Mars.” ®
