Nasa is trying one last time to contact its record-setting Mars rover Opportunity, before calling it quits.
The rover has been silent for eight months, victim of one of the most intense dust storms in decades.
Thick dust darkened the sky last summer and, for months, blocked sunlight from the spacecraft’s solar panels.
If there is no response by Wednesday, which Nasa suspects will be the case, Opportunity will be declared dead, 15 years after arriving at the red planet.
Team members are already looking back at Opportunity’s achievements, including confirmation water once flowed on Mars.
Opportunity was, by far, the longest-lasting lander on Mars.
Besides endurance, the six-wheeled rover set a roaming record of 28 miles.
Both outlived and outperformed expectations, on opposite sides of Mars.
The golf cart-size rovers were designed to operate as geologists for just three months, after bouncing onto our planetary neighbour inside cushioning air bags in January 2004.
They launched from Cape Canaveral a month apart in 2003.
It is no easier saying goodbye now to Opportunity, than it was to Spirit, project manager John Callas said.
“It’s just like a loved one who’s gone missing, and you keep holding out hope that they will show up and that they’re healthy,” he said.
“But each passing day that diminishes, and at some point you have to say ‘enough’ and move on with your life.”