Since 2013, the project known as MAVEN - for Mars Atmosphere and Volatile Evolution - was on a mission to study that planet's upper atmosphere, ionosphere and its interactions with the Sun. The spacecraft's signal was lost on the 6th of December after a pass behind the red planet, prompting NASA to immediately begin a review of what actions the agency would take next. At a media teleconference earlier this month, officials declared MAVEN to be no long useful and said there will be no attempts at recovering it.
Although MAVEN's original mission was to last only a year, it proved useful for more than a decade beyond that period as it continued to transmit data, even serving as an antenna during the delivery of the Perseverance rover to Mars in 2020.
Preliminary findings of MAVEN's failure determined that its batteries may have drained, shutting down its communications system, when it emerged from its orbit behind Mars. A review board is studying the mission to discover the cause while NASA decommissions the MAVEN program and archives its data.
