As big as a car and as well-equipped as a laboratory, NASA's newest Mars rover blows away its predecessors in size and skill. Nicknamed Curiosity and scheduled for launch on Saturday, the rover has a 7-foot arm tipped with a jackhammer and a laser to break through the Martian red rock. What really makes it stand out: It can analyze rocks and soil with unprecedented accuracy. "This is a Mars scientist's dream machine," said NASA Jet Propulsion Laboratory's Ashwin Vasavada, the deputy project scientist. Once on the red planet, Curiosity will be on the lookout for organic, carbon-containing compounds. While the rover can't actually detect the presence of living organisms, scientists hope to learn from the $2.5 billion, nuclear-powered mission whether Mars has or ever had what it takes to nurture microbial life. Curiosity will be "the largest and most complex piece of equipment ever placed on the surface of another planet," said Doug McCuistion, director of NASA's Mars exploration program.