NASA’s Mars helicopter, Ingenuity, suffered a scare during its sixth flight on the red planet when the aircraft lost stability in the air. Fortunately, the machine was able to overcome the situation and make a safe landing.
The flight took place on May 22, but NASA’s Jet Propulsion Laboratory (JPL), which is overseeing Ingenuity’s Mars mission, has only just revealed details of the event.
The helicopter’s sixth flight appeared to be going well as it set off on a planned 215-meter flight across the Martian surface at an altitude of 10 meters.
But 150 meters in, Ingenuity began changing its speed, tilting back and forth in an oscillating pattern, and suffering spikes in power consumption, with the unexpected behavior continuing throughout the rest of the flight.
After analyzing the incident, the team at JPL discovered a glitch in one of the systems that helps Ingenuity to estimate its motion and maintain stability in the air.
The system uses images of the ground taken by Ingenuity’s navigation camera. The images are fed through to an algorithm for rapid processing, with the resulting data causing the aircraft to make necessary adjustments in its position, velocity, and altitude.
On its sixth flight, a glitch in the pipeline of images delivered by the camera caused a single image to be lost, knocking the algorithm out of sync. This caused the 4-pound, 19-inch-high helicopter to mistime its adjustments, which led to the unexpected flight behavior.
“The resulting inconsistencies significantly degraded the information used to fly the helicopter, leading to estimates being constantly ‘corrected’ to account for phantom errors,” JPL said in its account of the incident, adding, “Large oscillations ensued.”
The team was relieved to report that, despite what happened, Ingenuity was able to maintain flight and safely touch down within about 5 meters of its targeted landing spot.
Ingenuity’s flights are autonomous, but it receives instructions for each of its aerial adventures from JPL engineers back in Southern California. In April, the machine became the first aircraft to achieve powered, controlled flight on another planet. Since then, it’s taken increasingly complex flights without any major malfunction occurring — until its most recent trip, that is.
Commenting on the incident, JPL said, “In a very real sense, Ingenuity muscled through the situation, and while the flight uncovered a timing vulnerability that will now have to be addressed, it also confirmed the robustness of the system in multiple ways.”
It added that, although it certainly didn’t plan to subject Ingenuity to such a stressful flight, the anomaly meant that it now possessed valuable flight data relating to “the outer reaches of the helicopter’s performance envelope.”
JPL said the data will be “carefully analyzed in the time ahead, expanding our reservoir of knowledge about flying helicopters on Mars.”