Washington — The U.S. space agency landed a 1-ton vehicle on Mars August 5, and the craft, named Curiosity, began returning images of its new surroundings within moments of its touchdown.

"Absolutely incredible; it doesn't get any better than this," said Charles Bolden, NASA's administrator, on NASA TV shortly after the landing. "This is a huge day for the nation."

Bolden said he hopes the American people recognize the significance of the achievement and realize "this is my rover on Mars."

The Mars Science Laboratory (MSL), with Curiosity aboard, flew eight months to reach its destination, across 570 million kilometers. Updates from the vehicle throughout the flight were good, but the difficulty of the landing loomed in the future, and won the nickname "seven minutes of terror."

NASA and its Jet Propulsion Laboratory (JPL), managing the mission, designed a completely new system to gently land the vehicle and its complex scientific equipment on the Martian surface. Moments before the difficult maneuvers were to begin, Rob Manning, JPL’s flight system chief engineer, said on NASA-TV, "It's easy for this not to work."

The spacecraft was traveling about 22,000 kilometers per hour when it hit the Martian atmosphere, after being accelerated by the gravity of the Red Planet. Guiding itself through onboard instruments with no assistance from Earth, the craft slowed to a soft touchdown in seven minutes with the aid of a parachute and a specially designed "sky crane" that lowered Curiosity to the surface.

NASA monitored the success of these events as Curiosity sent signals of its progress to the Mars orbiter Odyssey, which conveyed those on to the Deep Space Network of antennas on Earth. MSL sent a signal confirming Curiosity's touchdown, the message was relayed through Odyssey across a vast swath of the solar system, and a bolt of elation shot through the staff of scientists and technicians in the JPL control room in Pasadena, California.

Applause, cheers, back slaps, hugs and handshakes rippled across the control room. The joy and triumph that swept over the group rivaled any celebration seen on the Olympic medal stand in London.

The landing was "an incredible accomplishment," said John Holdren, science adviser to President Obama and another member of the excited crowd at JPL. "It's an enormous step forward in planetary exploration," Holdren said, because of Curiosity's increased capabilities in comparison to the earlier Mars rovers Spirit and Opportunity, which landed on the planet in 2004.

Curiosity will live up to its name and conduct real science on the Martian surface, searching for evidence the planet may have been habitable for life at some time in its history. At the same time it will reveal evidence of the planet’s history — how it formed, when was it hotter or colder. To help shed light on these questions, the craft is equipped with laboratory instruments capable of performing a variety of analytic tests on material samples gathered by the rover's robotic arm.

The instruments will be able to identify organic compounds and describe them down to the atomic level. Other instruments will be able to identify and quantify the minerals in rocks and soils, and the relative abundance of these different elements.

A camera mounted on the arm will take extreme close-up photos of rocks, soil, and even ice, if it is found, with the capability to reveal details smaller than the width of a human hair. The Radiation Assessment Detector will gather critical data to help scientists understand the planet's habitability for any life forms and possible human exploration.

Within moments of a successful touchdown, Curiosity returned its first image to the jubilant flight control team in California: a grainy image of the craft's own shadow, but an image from the surface of Mars nevertheless.

Curiosity's delivery of a self-portrait so soon after landing was by no means guaranteed. Would the cameras mounted on the rover function so early? Would they be obscured in a cloud of Martian surface dust? Would the orbiter still be in position to receive the signal from the rover and send it back to Earth? For NASA and JPL, it was a night when everything worked.

"It's an amazing thing," said Deputy Administrator Lori Garver on NASA-TV, expressing her uncertainty about the return of images "so soon, so clearly."

JPL mission control celebrated the technological achievement of landing the rover successfully, the flawless performance of the equipment, and the relief at the end of a long journey across the solar system. But it is only a beginning for an estimated two-year period of research and discovery.

"Let the science begin," Garver said.

The White House issued a congratulatory message to the NASA and JPL staffs and a sense of anticipation.

“I congratulate and thank all the men and women of NASA who made this remarkable accomplishment a reality,” President Obama’s statement said, "and I eagerly await what Curiosity has yet to discover."