Washington, Nov 26 : A nuclear-powered US rover lifted off on Saturday morning to help assess Mars' habitability, or whether the Red Planet is or ever was an environment able to support life.

The car-sized rover, atop an Atlas V rocket, blasted off at about 10.02 a. m. EDT (3.02 p. m. GMT)from Cape Canaveral Air Force Station in Florida, Xinhua reported, citing NASA TV.

The rover, nicknamed Curiosity, will journey for over eight months before touching down on Mars in August 2012, using a jet pack and tether system to be lowered to the surface.

Weighing nearly a ton, the six-wheeled vehicle, also known as the Mars Science Laboratory, dwarfs all the previous robots sent to the surface of the planet.

It is about twice as long and more than five times as heavy as any previous Mars rover. It has 10 scientific instruments, including two for ingesting and analyzing samples of powdered rock delivered by the rover's robotic arm.

During the prime mission lasting one Martian year -- nearly two Earth years -- researchers will use the rover's tools to study whether the landing region has environmental conditions favourable for supporting microbial life and preserving clues about whether life had existed. (IANS)