In less than three weeks, the Curiosity rover will land on Mars. To prepare, NASA this week has begun to reboot the rover's primary and back-up computer systems (called Rover Compute Elements) to minimize the chance of failure. As you can imagine, the seven-minute landing is the most challenging part of the Curiosity mission to the Red Planet; any number of variables can cause it to fail. What's more, this will be the first time NASA is employing its "sky crane" procedure—which involves a supersonic parachute and retro-rockets—to lower a rover onto a planet. Good thing NASA's engineers and scientists put the rover through its paces for years before its space launch. As we wait for Curiosity to touch down, take a look at some photos from the rover's prep period.