Steve Squyres is the face and voice of NASA's Mars Exploration Rover mission. Squyres dreamed up the mission in 1987, saw it through from conception in 1995 to a successful landing in 2004, and serves as the principal scientist of its $400 million payload. He has gained a rare inside look at what it took for rovers Spirit and Opportunity to land on the red planet in January 2004—and knows firsthand their findings.