Solar Cells on Rovers Keep Delivering

The Mars Carwash

Boy oh boy these little rovers just keep going. They have lasted so long that even the phrase extended mission no longer applies. More like the Energizer Bunny of scientific exploration.

Excerpt:
Opportunity's output also declined at first - to around 500 watt-hours - but over the past six months it has regained power (New Scientist print edition, 30 October). Lately, its solar cells have been delivering just over 900 watt-hours.

Rover team leader Jim Erickson at NASA's Jet Propulsion Laboratory in Pasadena, California, told New Scientist that a process still not understood has repeatedly removed dust from the solar panels. "These exciting and unexplained cleaning events have kept Opportunity in really great shape," he says.