The Mars Exploration Rover Mission was extremely successful. The rovers surpassed the original 90 day plan by many years and replaced meters of distance driven on Mars with kilometers. The above graphic (Credit: NASA/JPL-Caltech) indicates the many achievements of Spirit and Opportunity. Below are some of the original expected rover capabilities as stated in Crisp, J.A. et al. (2003), Mars Exploration Rover mission, JGR-Planets, Vol. 108 (E12), doi:10.1029/2002JE002038: LEARN MORE

• Mars Exploration Rovers: Spirit and Opportunity, from NASA: VIEW
• Mission objectives, timeline, traverse maps, and other information, from the Planetary Society: VIEW
• The Mars Exploration Rovers Update Archives (2004-2019): Exclusive coverage by journalist and MER PORTAL Interview Consultant A. J. S. Rayl: VIEW
• Mars Rover Mission Comes to an End, but Science, Legacy Live on, from JPL: VIEW
• Mars and Me, The unofficial diary of a Mars rover driver, five years delayed, by S. Maxwell: VIEW