A robotic dirt and ice digger rocketed toward Mars on Saturday, beginning a 422 million-mile journey that NASA hopes will culminate next spring in the first ever landing within the red planet's Arctic Circle.

The Phoenix Mars Lander blasted off before dawn, precisely on time, hurtling through the clear moonlit sky aboard an unmanned Delta rocket. The rocket looked as though it was heading straight for Mars, a bright reddish dot in the eastern sky.

Not quite six hours later, the Phoenix Mars Lander was already 365,000 miles from Earth and had settled into a cruising speed of more than 12,000 mph. Everything seemed to be working fine, mission officials said.

"Next stop is Mars," exulted Doug McCuistion, director of NASA's Mars exploration program.