A Sol refers to a single Martian day. Sol 5 is the fifth full day that Curiosity has been on Mars.

In an interview with Computerworld on Thursday, Steve Scandore, a senior flight software engineer at JPL, noted that a team of programmers and engineers have long been working on the software, as well as the upgrade process.

"You have to imagine that if something goes wrong with this, it could be the last time you hear from the rover," he said. "It has to work. You don't want to be known as the guy doing the last activity on the rover before you lose contact."

The surface software holds advanced controls to drive Curiosity, as well as to operate its 7-foot robotic arm, its ability to scoop up soil samples and its ability to spot hazards in its path.

"R10 has a lot of great stuff that the science team wants," said Cichy.