Since Ingenuity arrived on Mars everything has gone relatively well. While it experienced a minor issue in April that was fixed with a software update, the tests went according to plan. Nevertheless, on its sixth flight it registered its first “anomaly”. Fortunately the small aircraft managed to land safely.
The Ingenuity team had planned for the helicopter to undertake a scouting mission on its sixth flight. Mainly the idea was that it took images of the Martian landscape to land in a certain place. However, something happened to the navigation system and forced the aircraft to do correction calculations mid-flight.
According to NASA in a statement, the first 150 meters of the flight carried out on May 22 passed without problems. Towards the end of the mission an error occurred in the navigation camera system. Due to this, the navigation computer started receiving incorrect data from its data sources.
The navigation system, in an attempt to protect Ingenuity, began making “ghost bug” calculations. For a few seconds, while trying to correct himself, he experienced a series of frantic movements. Surprisingly, he managed to continue the missing leg of the flight and landed safely about 5 meters from the set location.
How does the Ingenuity navigation system work?
Credit: NASA Jet Propulsion Laboratory (JPL)
Ingenuity has a navigation system that is powered by two essential elements. One of them is a inertial measurement unit (IMU) that tracks how fast the rotor rotates to calculate acceleration, allowing its speed and position in the air to be estimated.
The other element is an is a small monochrome camera that takes 30 photos of the ground per second to give the helicopter a visual idea of where it is. These are images that are sent with timestamps and allow Ingenuity to analyze their trajectory.
Both channels converge on the Ingenuity navigation system. This Thursday, one of the images sent by the monochrome camera suddenly disappeared and the timestamps acquired incorrect values.
“From this point on, every time the navigation algorithm performed a correction based on a navigation image, it operated on the basis of incorrect information about when the image was taken,” explained Håvard Grip, Ingenuity’s chief pilot.