Months after NASA’s Ingenuity Mars Helicopter crash-landed on the dusty surface of Mars, scientists finally figured out what happened.

Ingenuity was the first aircraft to ever fly on another planet, sadly crashing to earth on its 72nd flight on January 18th this year.

Engineers from NASA’s Jet Propulsion Laboratory in Southern California and AeroVironment – who helped build the helicopter – have since been investigating the cause of the crash and have now concluded that it was due to a problem with the onboard navigation sensors.

Ingenuity was launched to Mars with the Perseverance rover in July 2020 and landed in the Martian Lake Crater in February 2021.

The helicopter was originally planned to operate for only 30 days, completing up to 5 test flights, but engineers were pleased to find that Ingenuity continued to operate well beyond that deadline.

In total, Ingenuity operated for nearly three years, flying more than 30 times farther than originally planned during a total of 72 flights.

According to NASA engineers, Ingenuity’s final flight ended on a sticky note after its navigation sensors failed to pick up enough detail from the smooth surface of Mars to accurately calculate its position. This resulted in the helicopter landing while moving horizontally at high speed, resulting in the rupture of all four of the craft’s rotors.

“When you’re conducting an accident investigation from 100 million miles away, you don’t have any black boxes or eyewitnesses,” Håvard Grip, a Jet Propulsion Laboratory engineer and Ingenuity’s first pilot, said in a statement.

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

Engineers pieced together the details of Ingenuity’s swan song using limited data transmitted back to Earth along with satellite images of the crash site.

They found that Ingenuity climbed to 40 feet and hovered to take photos before beginning its descent in 19 seconds. In 32 seconds, the helicopter crashed into the ground.

The helicopter’s navigation system tracks the ground with a downward-facing camera, which it uses to track visual features on the Martian surface. During its early flights, Ingenuity could determine its position using a flat, textured rocky surface, but its later flights were over an area of ​​land characterized by smooth, steep sand undulations.

After launch, Ingenuity’s cameras likely failed to track enough objects on the ground to accurately track its position, causing it to land at high horizontal speed, pitch and roll so vigorously that all of its rotors snapped and it lost contact with Earth.

“Because Ingenuity was designed to be affordable while requiring massive amounts of computing power, we became the first mission to fly commercial mobile phone processors in deep space,” Teddy Tzanetos, Ingenuity’s project manager, said in a statement.

“We are now approaching four years of continuous operation, which suggests that not everything needs to be bigger, heavier and more radiation-resistant to function in the harsh Martian environment.”

Despite being the last to land on the Red Planet, Ingenuity is still sending weather data back to Earth via the Perseverance rover. It also transmits data from domestic avionics tests that could hopefully help engineers design other aircraft for future Mars missions.

NASA recently announced that it is designing a larger “Mars Chopper” aircraft that will be 20 times heavier than Ingenuity and travel up to 2 miles each day.

“Ingenuity has given us the confidence and data to imagine the future of Mars flight,” Tzanetos concluded.