The Mars science rover Curiosity landed on the Martian surface shortly after 10:30pm Pacific US time on Sunday (0530 GMT) to begin a two-year mission seeking evidence the Red Planet once hosted ingredients for life, NASA has said.
Mission controllers at the Jet Propulsion Laboratory near Los Angeles said they had received signals relayed by a Martian orbiter confirming that the rover had survived a make-or-break descent and landing attempt to touch down as planned inside a vast impact crater.
NASA has described the feat as perhaps the most complex ever in robotic spaceflight. The $2.5bn Curiosity project, formally called the Mars Science Laboratory, is NASA's first astrobiology mission since the 1970s-era Viking probes.
The landing, a major victory for a US space agency beleaguered by budget cuts and the recent loss of its space shuttle programme, was greeted with raucous applause and tears of joy by jubilant engineers and scientists at mission control.
In what the head of NASA's Mars programme called a "daring" operation, the space agency landed its largest-ever rover, weighing 900kg, by carefully lowering it to the surface on cables from what amounts to a giant jet pack in a so-called sky crane manoeuvre.
The landing will be followed by orbiting satellites already deployed around Mars.
The mission will spend at least one Martian year, nearly two Earth years, studying Mars' Gale crater, in a bid to transition from the search for water to a wider search for the presence of other ingredients necessary for life, such as carbon.
It will also study minerals on the surface to get an idea what conditions were like on the planet millions of years ago.