Back in March, we reported that NASA had raised concerns over the health of Spirit, one of the Mars rovers that landed on the red planet back in 2004. Spirit‘s problems began back in January of last year when NASA reported that the rover’s mission was concluded as a result of it getting stuck in the Martian sand. At that point, Spirit began operations as a stationary research platform until it went into hibernation in March 2010.Since then Spirit has been silent. NASA had originally hoped that Spirit might finally wake up when the rover reached its peak solar energy production on March 10th of this year, but alas there was no response. It is believed that a “stressful” Martian winter without much sunlight may have contributed to Spirit’s demise since it likely experienced colder internal temperatures than its previous six years on the planet. Some of the rover’s components are believed to have been damaged by the cold since there was inadequate solar energy to power Spirit’s survival heaters.AdChoices广告As a result, NASA has ceased all attempts to contact the rover using its Deep Space Network of antennas on Earth in addition to its two Mars orbiters. Due to the low probability that Spirit will once again establish communications these communication assets are now being transitioned to NASA’s Mars Science Laboratory (MSL). The MSL is NASA’s next generation Mars rover that is expected to launch on November 25th of this year. NASA did state that its Deep Space Network may listen for signals from Spirit when “the schedule permits.”Opportunity, an identical rover that landed on Mars three weeks after Spirit, is in much better shape and continues to explore the planet’s surface. Opportunity’s current odometry as of May 18, 2011 is over 18 miles.Read more at NASABrian’s OpinionEven with the demise of Spirit you can easily say NASA got its money’s worth out of the rover while Opportunity continues to pay dividends. It’s a bit mind boggling to think that both rovers were designed for a 90 day mission. Spirit well exceeded its warranty and Opportunity continues to add more days on to the record books.It’s a little sad to think that even Opportunity will stop getting the attention it deserves when the next generation Mars rover, MSL, lands on the red planet. Once on the surface, NASA may be a bit quicker to transfer assets over to MSL if Opportunity begins to show signs of slowing down.Spirit and Opportunity were a game changer for NASA after suffering mishaps with other spacecraft sent to explore Mars. It was for this reason NASA sent two rovers in an effort to double its chances for success. I can’t imagine anyone would have predicted how successful the rovers were going to be, let alone that they would operate for years rather than months on the surface of Mars.