A top-down view of the solar panels that power NASA's Mars rover Opportunity. Credit: NASA/JPL

NASA is waiting for a big dust storm on Mars to clear a little more before attempting to waken the sleeping Opportunity rover, the agency said on 30 August. The rover has been silent since 10 June, when the storm obscured the sunlight that the spacecraft needs to survive.

When the dust abates, NASA will use the antennas of its global Deep Space Network to listen for signals from the spacecraft, and send messages to it, for at least 45 days. After that the agency will listen, possibly in a more passive mode that requires fewer staff hours, until at least January 2019. By that point, the Martian summer will have given way to autumn at Opportunity’s landing site. That change in seasons could kick up windstorms and clear any dust that might be coating the rover’s solar panels.

The rover could be awoken by a NASA signal if it receives enough sunlight to recharge its batteries. It could also awaken itself, without a prompt, and attempt to communicate with Earth. The Martian dust storm of the past few months has been one of the most extensive ever seen on the red planet.

Opportunity was designed to last for 90 Martian days, or about 13 Earth weeks. Yet it has survived for 14 years on the surface — rolling more than 45 kilometres from its landing site to its current resting place, in a spot called Perseverance Valley. Its discoveries include signs of an ancient habitable environment on Mars 4 billion years ago.

“It’s been an enormously productive run, and the return on investment is just tremendous,” says Raymond Arvidson, a planetary scientist at Washington University in St. Louis, Missouri, and the mission’s deputy principal investigator. “It’s a sad situation but not really unexpected.”