Jet Propulsion Lab says goodbye to Mars rover Spirit

Scientists at Pasadena's Jet Propulsion Laboratory are giving up on the Martian rover Spirit. The six-wheeled robot has been mired in sand for about two years, and the final commands issued early Wednesday produced no response.

NASA project managers said goodbye to the vehicle.

"Last night, just after midnight, the last recovery command was sent to Spirit," John Callas, the Mars Exploration Rover Project manager, wrote to his team. "It would be an understatement to say this was a significant moment. Since the last communication from Spirit on March 22, 2010, as she entered her fourth Martian winter, nothing has been heard from her."

Despite being stuck, the rover performed beyond expectations and has been on the Red Planet since January 2004. Its twin, Opportunity, landed on the other side of the planet.

Spirit started out with some problems in its electronic memory, but detected evidence of water-altered rocks and carbonates -- both building blocks of life -- on what scientists call the Gusev site.

But the rover found evidence that Mars was once like Earth, with water and hot springs. Concentrated deposits of silica led the project's principal investigator to conclude that steam vents or hot springs once existed at a site known as Home Plate. Such an environment could have supported microbial life.

After its first year on Mars, the rover lost the use of one of six wheels while scrambling over a hilly area, but continued to send data back to Earth for years. It logged 4.8 miles over the Martian surface — about a dozen
times farther than it was expected to go.

Opportunity is still working. It has logged 12 miles, collected more than 130,000 images and is headed toward a crater called Endeavour.

Audio: KPCC talked with John Callas, the project manager of the Rover mission, about finally calling it quits.