NASA's Mars rover Curiosity blasts off

CAPE CANAVERAL, Fla. -- A rover of "monster truck" proportions zoomed toward Mars on an 8 1/2-month, 354 million-mile journey Saturday, the biggest, best-equipped robot ever sent to explore another planet.

NASA's six-wheeled, one-armed wonder, Curiosity, will reach Mars next summer and use its jackhammer drill, rock-zapping laser and other devices to search for evidence that Earth's neighbor might once have been home to the teeniest forms of life.

More than 13,000 invited guests jammed the Kennedy Space Center on Saturday morning to witness NASA's first launch to Mars in four years, and the first flight of a Martian rover in eight years.

Mars fever gripped the crowd.

NASA astrobiologist Pan Conrad, whose carbon compound-seeking instrument is on the rover, jumped, cheered and snapped pictures as the Atlas V rocket blasted off. So did Los Alamos National Laboratory's Roger Wiens, a planetary scientist in charge of Curiosity's laser blaster, called ChemCam.

Surrounded by 50 U.S. and French members of his team, Wiens shouted, "Go, Go, Go!" as the rocket soared into a cloudy sky.

The 1-ton Curiosity -- almost 10 feet long, 9 feet wide and 7 feet tall at its mast -- is a mobile, nuclear-powered laboratory holding 10 scientific instruments that will sample Martian soil and rocks, and with unprecedented skill, analyze them on the spot.

It's as big as a car. But NASA's Mars exploration program director calls it "the monster truck of Mars." "It's an enormous mission. It's [the] equivalent of three missions, frankly, and quite an undertaking," said the ecstatic program director, Doug McCuistion.

The goal of the $2.5 billion mission, expected to last at least 2 years, is to see whether cold, dry, barren Mars might once have been hospitable for microbial life -- or might even be conducive to life now. No actual life detectors are on board; rather, the instruments will hunt for organic compounds.

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