NASA's Mars Helicopter Lost Control In Mid-Air Due To A Navigation Error
By Bill Galluccio
May 28, 2021
The helicopter on NASA's Mars rover Perseverance had a scare during its sixth test flight. The Ingenuity helicopter ran into problems shortly after taking off when a navigation error caused it to lose control while it was 33 feet off the ground.
Officials at NASA's Jet Propulsion Laboratory said the issue occurred when a photo taken from an onboard camera failed to register in the craft's navigation system. That caused a chain reaction, as all subsequent images loaded into the system had an inaccurate time stamp. As a result, the helicopter began to tilt back and forth as much as 20 degrees because the navigation systems couldn't identify its location.
Havard Grip, the helicopter's chief pilot, said that NASA engineers planned for issues like this.
"We designed Ingenuity to tolerate significant errors without becoming unstable, including errors in timing. This built-in margin was not fully needed in Ingenuity's previous flights because the vehicle's behavior was in-family with our expectations, but this margin came to the rescue in Flight Six," Grip explained in a blog post.
"We stop using navigation camera images during the final phase of the descent to landing to ensure smooth and continuous estimates of the helicopter motion during this critical phase. That design decision also paid off during Flight Six: Ingenuity ignored the camera images in the final moments of flight, stopped oscillating, leveled its attitude, and touched down at the speed as designed," he added.
The helicopter managed to land safely about 16 feet from its intending landing zone.
Grip said that NASA engineers expect to learn a lot from the mishap as they examine all the data.
"While we did not intentionally plan such a stressful flight, NASA now has flight data probing the outer reaches of the helicopter's performance envelope. That data will be carefully analyzed in the time ahead, expanding our reservoir of knowledge about flying helicopters on Mars."
Photo: Getty Images