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 20: As of yesterday evening, the week-long reboot and configuration activities on Curiosity's two redundant main computers, or Rover Compute Elements -- including the uplink of spacecraft configuration parameters for entry, descent and landing -- were completed, a day ahead of schedule. Today, backup software for Curiosity's entry, descent and landing is being configured onboard the Mars Science Laboratory spacecraft. In case Curiosity's prime computer resets for any reason during the critical minutes of entry, descent and landing, this backup software is designed to enable Curiosity's backup computer to promptly take control and finish the landing with a bare-bones version of entry, descent and landing instructions.