Ingenuity Perseveres Through Stressful Sixth Flight

NASA’s Ingenuity helicopter took to the Martian skies for a sixth time, but the flight turned out to be much more stressful that its previous outings. An error in the navigation system caused the tiny craft to twist and turn unexpectedly, but in the end made a successful landing.

Ingenuity is a technology demonstration mission that arrived on Mars along with the Perseverance rover earlier this year.  NASA often says the name Perseverance, selected from names submitted by students, turned out to be quite apt considering that final preparations for launch were made in the difficult days of the COVID-19 pandemic.

What happened to Ingenuity on this sixth flight is another testament to the word.

Ingenuity was only designed to fly five times on Mars, but after acing those missions, NASA gave it an operational assignment working in conjunction with the rover.

Its first flight in this new role took place on May 22, but NASA only posted a description of what happened today.

Previously, Ingenuity’s highest altitude was 5 meters (16 feet).  This time, it was commanded to rise to 10 meters (33 feet), move 150 meters (492 feet) to the southwest at 4 meters per second (9 miles per hour), then move 15 meters (49 feet) to the south, then 50 meters (164 feet) northeast and land.

The first 150 meter leg went fine, but then Ingenuity began oscillating.

The good news is it landed safely.

Ingenuity’s chief pilot, Håvard Grip, explained that during flight, Ingenuity is guided not only by an Inertial Measurement Unit (IMU), but by comparing images of what it should be seeing with what it actually is seeing through its navigation camera that collects 30 images per second and feeds them to the helicopter’s navigation system.

This time, for some reason, a “glitch occurred in the pipeline of images” and an image was lost. That meant subsequent images had incorrect time stamps and the navigation system operated on incorrect information.

“The resulting inconsistencies significantly degraded the information used to fly the helicopter, leading to estimates being constantly ‘corrected’ to account for phantom errors. Large oscillations ensued.”

Fortunately, Ingenuity does not use those images during the final phase of descent so it stopped oscillating and landed safely.

Grip wrote: “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.”

Ingenuity, Perseverance, and other Mars spacecraft must operate autonomously because of the time-lag in communications between Earth and the Red Planet, which is about 11 minutes round-trip. The spacecraft are sent commands to perform certain operations, but ground controllers do not know how everything turned out until after it is all over.