NASA has lost contact with its Maven spacecraft, which has orbited Mars since 2014, after it failed to communicate following its passage behind the planet.

Maven, launched in 2013, studies Mars’ upper atmosphere and its interaction with the solar wind, helping explain how the planet lost much of its atmosphere over time.

The spacecraft also serves as a communication relay for the Curiosity and Perseverance rovers.

NASA engineers are investigating the cause of the sudden silence, ABC News has reported.

Two other Mars orbiters, Mars Reconnaissance Orbiter and Mars Odyssey, remain active and operational.