Since the 1960s, humans have invaded our neighboring planet Mars with swarms of spacecraft. Only about half of the attempts have been successful. See how many robot missions to Mars have launched in this SPACE.com infographic. [&lt;a href=&quot;http://www.space.com/16575-mars-exploration-robot-red-planet-missions-infographic.html&quot;&gt;See the Full Occupy Mars Infographic&lt;/a&gt;]