The US space agency has regained contact with its tiny helicopter on the planet Mars after an unexpected communication breakdown prompted fears the research craft had been damaged or destroyed.
Nasa's Ingenuity drone arrived on Mars in 2021 aboard the Perseverance rover.
The 0.5-metre tall drone is the first motorised craft to fly autonomously on another planet and has been transmitting data back to Earth via Perseverance.
Contact with Ingenuity cut out suddenly on Thursday during its 72nd flight on Mars.
But Nasa said it had been re-established late on Saturday.
"Good news today," Nasa's Jet Propulsion Laboratory (JPL) wrote on X, formerly Twitter.
The agency said contact had been made with the helicopter by commanding Perseverance to "perform long-duration listening sessions for Ingenuity's signal".
"The team is reviewing the new data to better understand the unexpected coms dropout during Flight 72," it added.
Ingenuity's Flight 72 was a test mission aimed at checking out the craft's systems after an early unplanned landing during a previous flight.
Nasa said the drone reached an altitude of 12 metres but faced problems on descent.
"Communications between the helicopter and rover terminated early, prior to touchdown," the agency said.
JPL had on Friday noted Perseverance was temporarily "out of line-of-sight with Ingenuity, but the team could consider driving closer for a visual inspection".
In a response to a post on X asking if Ingenuity would be able to fly again, JPL on Saturday said "the team needs to assess the new data before that can be determined".
Nasa has lost contact with the helicopter before, including for two months last year.
Mars is known to be a “graveyard for spacecraft”, because of the planet’s powerful dust storms and unstable terrain that can damage rovers and other technology.
Despite the harsh conditions, Ingenuity has proved remarkably durable. It has survived glacially cold Martian nights, kept warm by the solar panels that recharge its batteries during daylight hours.
Ingenuity has far exceeded its original goal of making five successful flights over 30 days, with 72 flights since arriving in 2021.
The mini craft, which weighs only 1.8kg, has covered more than 17km and reached altitudes of up to 24m.
The drone serves as an aerial scout to assist the Perseverance as it searches the Red Planet for possible signs of ancient microbial life or other discoveries.
