The Mars science rover Curiosity landed on the Martian surface shortly after 10:30 pm 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 $2.5 bn 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 program, 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.
NASA had promoted the dramatic landing in a video game and had invited space fans across the US to gather to watch the arrival live, including on the giant screens in New York's Times Square.
The landing will be followed by orbiting satellites already deployed around Mars.
The mission is also being streamed live on NASA's website .
Zooming toward the surface at 17 times the speed of sound, after its nearly nine-month journey, the craft carrying Curiosity decelerated using thrusters and a parachute.
Along the way it jettisoned its cruising rockets, heat shield and outer shell - going through six different vehicle configurations - before gently lowering the rover to the Martian surface like a spider on a thread.
The new routine involved Curiosity steering itself for the final phase of landing.
Due to the signal time lag between Mars and Earth (it takes about 14 minutes for a signal on Mars to reach Earth), Curiosity executed the landing autonomously.
One Martian year
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.
The Gale crater is nearly 154km in diameter and features a mountain that rises some 5km above the surface.
The massive feature includes layers of rock strata that will provide a virtual history of Mars' geological past.
Curiosity will make use of a range of new instruments. Armed with two cameras atop a mast, Curiosity can take three-dimensional and panoramic images, and shoot a laser into rocks to determine their component chemical elements.
A 2m long robotic arm can be extended out from the rover to examine its surroundings more closely, and a drill will allow it to take samples from inside rocks.
The area has already been studied extensively from orbiting spacecraft, and scientists hope that Curiosity will provide clues to a probable wet Martian past.
The area contains clay and sulfate-rich areas, where organic compounds necessary to life could be found.
Like its predecessors, Curiosity is equipped with a series of instruments to analyse the composition of the samples. It builds on the work of past rovers, including Opportunity, one of a pair of water-hunting twin rovers that continued functioning years beyond their orginal missions.
NASA eventually hopes to send a manned mission to Mars, and robotic missions to Earth's nearest planetary neighbour have continued. Mars is the chief component of NASA's long-term deep space exploration plans.