The world's biggest extra-terrestrial explorer, NASA's Curiosity rover

NASA launches giant rover ‘curiosity’ to Mars 

The world's biggest extra-terrestrial explorer, NASA's Curiosity rover, rocketed toward Mars on Saturday on a search for evidence that the red planet might once have been home to itsy-bitsy life.

It will take eight-and-a-half months for Curiosity to reach Mars following a journey of 354 million miles.

An unmanned Atlas V rocket hoisted the rover, officially known as Mars Science Laboratory, into a cloudy late morning sky.

A Mars frenzy gripped the launch site, with more than 13,000 guests jamming the space centre for NASA's first launch to Earth's next-door neighbor in four years, and the first send-off of a Martian rover in eight years.

The primary goal of the $2.5 billion mission is to see whether cold, dry, barren Mars might have been hospitable for microbial life once upon a time - or might even still be conducive to life now. No actual life detectors are on board; rather, the instruments will hunt for organic compounds.

Curiosity's 7-foot arm has a jackhammer on the end to drill into the Martian red rock, and the 7-foot mast on the rover is topped with high-definition and laser cameras. No previous Martian rover has been so sophisticated or capable.

With Mars the ultimate goal for astronauts, NASA also will use Curiosity to measure radiation at the red planet. The rover also has a weather station on board that will provide temperature, wind and humidity readings; a computer software app with daily weather updates is planned.

The world has launched more than three dozen missions to the ever-alluring Mars, which is more like Earth than the other solar-system planets. Yet fewer than half those quests have succeeded.

Curiosity's arrival next August will be particularly hair-raising.

In a spacecraft first, the rover will be lowered onto the Martian surface via a jet pack and tether system similar to the sky cranes used to lower heavy equipment into remote areas on Earth.

Curiosity is too heavy to use air bags like its much smaller predecessors, Spirit and Opportunity, did in 2004. Besides, this new way should provide for a more accurate landing.

Astronauts will need to make similarly precise landings on Mars one day.

Curiosity will spend a minimum of two years roaming around Gale Crater, chosen as the landing site because it's rich in minerals.

Scientists said if there is any place on Mars that might have been ripe for life, it would be there.