This artist concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life.

July 19: With updated flight sequences and communications parameters for entry, descent and landing and surface operations now uploaded to one of Curiosity's two redundant main computers -- Rover Compute Element (RCE)-B -- today RCE-A is being swapped back to become Curiosity's prime computer, and RCE-B is returning to backup mode. Prime computer RCE-A will then receive its own set of updated flight sequences and communications parameters.