NASA has lost contact with its tiny helicopter Ingenuity during the hard-working craft's 72nd flight, the space agency said.
The agency's engineers are attempting to re-establish communications, which ended abruptly on Thursday as the craft was making its descent from a test flight, NASA said late Friday.
Ingenuity, which resembles a large drone, had arrived on Mars in 2021 with the rover Perseverance and became the first motorized craft to fly autonomously on another planet.
Data from the helicopter's flights are transmitted via Perseverance back to Earth.
On its flight Thursday -- "a quick pop-up vertical flight to check out the helicopter’s systems, following an unplanned early landing during its previous flight," NASA said -- Ingenuity successfully attained an altitude of 40 feet (12 meters).
But "during its planned descent, communications between the helicopter and rover terminated early, prior to touchdown," the agency said, adding that "the Ingenuity team is analyzing available data and considering next steps to reestablish communications."
In a post on X, the former Twitter, NASA's Jet Propulsion Laboratory added that Perseverance was temporarily "out of line-of-sight with Ingenuity, but the team could consider driving closer for a visual inspection."
NASA has lost contact with the helicopter before, including for an agonizing two months last year.
The mini rotorcraft, which weighs just four pounds (1.8 kilograms), has far exceeded its original goal of undertaking five flights over 30 days on the red planet.
In all, it has covered just over 10 miles (17 kilometers) and reached altitudes of up to 79 feet (24 meters).
Its longevity has proved remarkable, particularly considering that it must survive glacially cold Martian nights, kept warm by the solar panels that recharge its batteries during daylight hours.
Working with Perseverance, it has acted as an aerial scout to assist its wheeled companion in searching for possible signs of ancient microbial life.