Opportunity and its twin Spirit landed on Mars in January 2004 , and mission was supposed to last for three-months . But the rover failed after only two weeks of operation due to a problem with one of its wheels ( which is why it's called " wheel failure ).
Opportunity and its twin Spirit landed on Mars in January 2004 , and mission was supposed to last for three-months . Last year , Opportunity broke record for off-Earth distance traveled beating Soviet Union 's Lunokhod 2 moon rover .