article_snippet: Opportunity and its twin Spirit its twin Spirit Spirit landed on Mars in January 2004 for what was supposed to be a three-month mission.
article_snippet: Spirit's mission ended in 2011 not long after Spirit's mission got stuck in Martian sand.
article_snippet: Opportunity and its twin Spirit the Soviet Union Spirit landed on Mars in January 2004 for what was supposed to be a three-month mission.
article_snippet: Spirit's mission ended in 2011 not long after Spirit's mission got stuck in Martian sand. '
highlights_snippet: Opportunity and its twin Spirit landed on Mars in January 2004, and mission was supposed to last for three-months .
  