The Mars rover Curiosity is set to land this weekend, and in honor of the event, Wired is taking a look back at the missions that didn't make it. Many will be watching online, on television, or in Times Square as the $2.5 billion Curiosity attempts to survive "seven minutes of terror" to safely land on Mars. More than half of all Mars missions have failed, and the current success rate for landing probes on the planet's surface sits at about 30 percent. This mission presents a particular challenge as the largest man-made object to land on another planet, but probability isn't completely against Curiosity — three out of four US-made rovers have successfully landed.