NASA’s Ingenuity Mars Helicopter is once again taking flight over the red planet, following an emergency landing in July that grounded the craft for several weeks.

The American space agency said on 7 August the Ingenuity helicopter successfully completed its 54th flight on 3 August, a short 25s “up-and-down hop” that was meant to assess why the autonomous rotorcraft executed an unplanned landing during its previous flight.

“A flight-contingency program was triggered, and Ingenuity automatically landed,” NASA’s Jet Propulsion Laboratory (JPL) says of the problematic 53rd Mars flight, which occurred on 22 July. “The total flight time was 74 seconds.”

Ingenuity Flight 53 was intended to be a 136s scouting mission to collect imagery of the Martian surface. NASA describes the objective as a “complicated flight profile” involving multiple ascents and descents, a hover and a flight speed of 4.8kt (9km/h) and up to 33ft altitude. The agency uses the helicopter to scout the terrain ahead of its rover mothership on the ground. 

“Since the very first [Ingenuity] flight we have included a programme called ‘LAND_NOW’ that was designed to put the helicopter on the surface as soon as possible if any one of a few dozen off-nominal scenarios was encountered,” says Teddy Tzanetos, team lead emeritus for Ingenuity at JPL. “During Flight 53, we encountered one of these, and the helicopter worked as planned and executed an immediate landing.”

NASA now believes the emergency landing procedure was triggered when images from Ingenuity’s navigational camera did not match data from the autonomous vehicle’s inertial measurement unit. That instrument measures Ingenuity’s acceleration and rotational rates, “data that makes it possible to estimate where the helicopter is, how fast it is moving and how it is oriented in space”, according to JPL.

A similar issue occurred in 2021, during the 6th flight of the Mars rotorcraft.

The JPL team used a software update to mitigate the risk of dropped navigational images, following that incident. However, the issue experienced on 22 July exceeded the limits of that solution, JPL says.

“While we hoped to never trigger a LAND_NOW, this flight is a valuable case study that will benefit future aircraft operating on other worlds,” says Tzanetos. “The team is working to better understand what occurred in Flight 53, and with Flight 54’s success we are confident that our baby is ready to keep soaring ahead on Mars.”

Mars image from Ingenuity

Source: NASA/JPL-Caltech

The Ingenuity Mars Helicopter took this image of NASA’s Perseverance Mars rover – visible at the top, right of centre – from an altitude of 16ft above the Martian surface during the autonomous rotorcraft’s 54th flight on 3 August

Flight 53 was Ingenuity’s first flight after a two-month period in which NASA lost contact with the Mars helicopter. Communication between the craft and mission controllers on Earth cut out on 26 April, during Ingenuity Flight 52.

NASA was able to re-establish contact with Ingenuity by driving the ground-based Perseverance rover toward the helicopter’s last known position – where the more powerful rover could act as signal relay.

Programme officials with NASA say Ingenuity’s role as an advanced scout for the slower moving Perseverance leaves it vulnerable to occasional signal loss.

“The portion of Jezero Crater the rover and helicopter are currently exploring has a lot of rugged terrain, which makes communications dropouts more likely,” said JPL’s Ingenuity team lead Josh Anderson in July.

“The team’s goal is to keep Ingenuity ahead of Perseverance, which occasionally involves temporarily pushing beyond communication limits,” he added.

Ingenuity made its first Martian flight in April 2021, initially serving as a technology demonstrator. The craft began operationally supporting the Perseverance mission in May of that year.