FILE - In this Thursday, Aug. 2, 2012 file photo, Adam Steltzner, Mars Science Laboratory's entry, descent and landing phase leader at NASA's Jet Propulsion Laboratory, uses a scale model to explain ... more 
FILE - In this Thursday, Aug. 2, 2012 file photo, Adam Steltzner, Mars Science Laboratory's entry, descent and landing phase leader at NASA's Jet Propulsion Laboratory, uses a scale model to explain the Curiosity rover's path to the surface during a news conference at the laboratory, in Pasadena, Calif. The rover is headed for a two-year mission to study whether Mars ever had the elements needed for microbial life. (AP Photo/Damian Dovarganes, File) less 
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Associated Press | Photo By Damian Dovarganes, File
Fri, Aug 3, 2012 4:01 PM EDT