And in a new twist, engineers came up with a way to lower the rover by cable from a hovering rocket-powered backpack. At touchdown, the cords cut and the rocket stage crashed a distance away.
The nuclear-powered Curiosity, the size of a small car, is packed with scientific tools, cameras and a weather station. It sports a robotic arm with a power drill, a laser that can zap distant rocks, a chemistry lab to sniff for the chemical building blocks of life and a detector to measure dangerous radiation on the surface.
It also tracked radiation levels during the journey to help NASA better understand the risks astronauts could face on a future manned trip.
Over the next several days, Curiosity is expected to send back the first color pictures. After several weeks of health checkups, the six-wheel rover could take its first short drive and flex its robotic arm.
The landing site near Mars' equator was picked because there are signs of past water everywhere, meeting one of the requirements for life as we know it. Inside Gale Crater is a 3-mile-high mountain, and images from space show the base appears rich in minerals that formed in the presence of water.
Previous trips to Mars have uncovered ice near the Martian north pole and evidence that water once flowed when the planet was wetter and toastier unlike today's harsh, frigid desert environment.
Curiosity's goal: to scour for basic ingredients essential for life including carbon, nitrogen, phosphorous, sulfur and oxygen. It's not equipped to search for living or fossil microorganisms. To get a definitive answer, a future mission needs to fly Martian rocks and soil back to Earth to be examined by powerful laboratories.
The mission comes as NASA retools its Mars exploration strategy. Faced with tough economic times, the space agency pulled out of partnership with the European Space Agency to land a rock-collecting rover in 2018. The Europeans have since teamed with the Russians as NASA decides on a new road map.
Despite Mars' reputation as a spacecraft graveyard, humans continue their love affair with the planet, lobbing spacecraft in search of clues about its early history. Out of more than three dozen attempts -- flybys, orbiters and landings -- by the U.S., Soviet Union, Europe and Japan since the 1960s, more than half have ended disastrously.
One NASA rover that defied expectations is Opportunity, which is still busy wheeling around the rim of a crater in the Martian southern hemisphere eight years later.
Mars mission: http://www.nasa.gov/msl