Investigating an aircraft crash is no simple task here on Earth. Imagine how much more difficult it would be to diagnose a helicopter accident that took place 69 million miles away with none of the usual data present to help. NASA had to do just that after its Ingenuity Mars Helicopter suffered an accident on Jan. 18, 2024, that has since left it grounded in a crater on Mars. And now, after months of collecting data, the space agency may have finally figured out what happened.
On April 19, 2021, the NASA Ingenuity Mars Helicopter made history by lifting off the Jezero Crater's floor and becoming the first aircraft to fly on a celestial entity other than Earth. The helicopter was supposed to fly only five experimental flights over 30 days to demonstrate that flight on Mars was possible. But it exceeded all expectations, conducting 72 flights over three years, setting all sorts of altitude records in the process, ending with that early 2024 accident.
The final moments of the helicopter's flight were more or less a mystery at first. Ingenuity lifted off like it had 71 times before. Then camera footage showed that it began initiating descent after just 19 seconds of flight. By the time 32 seconds had elapsed, the helicopter was on the Martian surface again and had halted communications. Six days later, the helicopter beamed back images that showed it had sustained severe rotor-blade damage and would no longer be able to fly.
Read more: NASA Ingenuity: Meet the woman launching a helicopter on Mars
Now, NASA believes that the navigation system was ultimately to blame. The navigation system used the helicopter's downward-facing camera to track visual features on the ground. During this final flight, the helicopter was flying over a portion of the Jezero Crater that is known for textured, featureless sand ripples. The navigation system was thus unable to find any suitable ground features to track for a landing.
From there, several things went wrong. NASA says that the helicopter made hard contact with a sand-ripple slope, causing it to pitch and roll. The sudden change in altitude was too much for the rotor blades, and four of them broke off at their weakest points. This caused the rotor system to vibrate excessively, which ripped one of the blades clean off. Finally, the incident generated an excessive power draw that caused communications to fail.
"When running an accident investigation from 100 million miles away, you don't have any black boxes or eye witnesses," said Håvard Grip, Ingenuity's first pilot and research technologist at JPL Robotics. "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."
Read more: Watch NASA's Mars helicopter Ingenuity make first flight on another planet
Lessons learned
Nobody expected Ingenuity to last as long as it did. Its flights gave researchers excellent aerial views of our red neighbor. Even now, as it lies in the sands of the Jezero Crater, Ingenuity can no longer fly but still beams back weather and avionics data to NASA. The avionics data along with the flight data from Ingenuity's 72 flights -- combined with Ingenuity's incredible longevity -- are helping NASA develop smaller, lighter avionics for future aircraft on Mars.
"Because Ingenuity was designed to be affordable while demanding huge amounts of computer power, we became the first mission to fly commercial off-the-shelf cellphone processors in deep space," said Ingenuity project manager Teddy Tzanetos. "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 and his team are already working on another Mars helicopter. It's approximately 20 times heavier than the Ingenuity and is being designed to carry several pounds of science equipment while autonomously exploring remote locations on Mars.