The U.S. space agency has launched the newest of its Mars rovers on a two-year mission to find places where life may have existed on the red planet.

NASA's $2.5-billion Mars Science Laboratory, known as Curiosity, took off Saturday from Cape Canaveral, Florida on an unmanned rocket.

The size of a car, the rover has 17 cameras, a robotic arm, a laser, and a drill to break through the planet's rock. The rover is expected to reach Mars in August. The intended landing site is a 150-kilometer-wide depression called Gale Crater, named for Australian astronomer Walter Gale.

The crater's geological features include many places where scientists believe water may have once flowed, as well as a high, broad mountain that mission managers say will be a main focus. The scientists have said the rover's mission will help reveal secrets of Mars' environmental history.

The NASA scientists say the rover's instruments will be used to study whether the landing region had favorable conditions for supporting microbial life. They say Curiosity will not be on a life-detection mission and will not be searching for fossils.

The six-wheeled Curiosity is the largest of the rovers NASA has sent to Mars. The 900-kilogram rover is about two meters tall and two meters long and wide. It is about twice the size of previous rovers Spirit and Opportunity.