Nation How Mars Opportunity rover ranks in list of more than 1,000 unmanned space missions by NASA since 1958 February 14, 2019Mike James, USA TODAYComments Off on How Mars Opportunity rover ranks in list of more than 1,000 unmanned space missions by NASA since 1958 The Mars Opportunity rover's 15-year mission: To boldly go into Martian craters everywhere. But now that it's over, where does it rank?
