The Phoenix Mars Lander lifted off flawlessly. Photo by nasa.gov
Officials hope it will find traces of organic compounds in the baked and moistened samples. That would be a possible indicator of conditions favorable for life, either now or once upon a time.
Only 5 of the world's 15 attempts to land on Mars have succeeded.
NASA's latest mission to Mars is on its way after a probe designed to find out if the Red Planet can support life was blasted off on Saturday.
An unmanned Delta rocket blasted off from Florida before dawn, carrying the Phoenix Mars Lander, equipped with a robotic dirt and ice digger.
Phoenix will touch down the icy surface of the planet's Mars' Arctic Circle. It will spend three months scooping up soil and ice, and analyzing the samples in tiny ovens and mixing bowls.
Scientists believe conditions in this region are the most likely to yield evidence of past or present life.
The spacecraft, which is due to reach Mars on May 25 next year after a journey of 422 million miles, is fitted with a robotic arm for scooping up samples of muddy, icy Martian soil to a depth of 55 centimetres.