NASA's had a robotic presence on Mars since 2003. Spirit operated from 2003-2010, Opportunity from 2003-present, Curiosity from 2012-present. All of these have been fairly widely reported in pop culture, and NASA continues to actively make & publicize discoveries from them:<p><a href="http://mars.nasa.gov/mer/home/" rel="nofollow">http://mars.nasa.gov/mer/home/</a>