A lander carrying the Spirit rover made what NASA officials called a textbook touch-down on Saturday in a huge impact crater, bouncing and rolling across the bleak landscape while cushioned by giant airbags.
The succesful landing caps seven months of space travel and plunges through the Martian atmosphere.
Project scientists at the space agency's Jet Propulsion Laboratory in Pasadena, California, broke into applause when the lander sent a signal back to Earth, telling them it had survived a final six-minute plummet to the surface.
NASA Administrator Sean O'Keefe, on hand for what was a critical moment for his agency, popped champagne at a post-landing press briefing.
Mars has proven a tough challenge for NASA, which lost two spacecraft there in 1998 and 1999, and officials said more than half of man's missions to the red planet had failed.
"This is a big night for NASA we're back," O'Keefe declared. "I'm very, very proud of this team and we're on Mars. This is an absolutely incredible accomplishment."
The presence of O'Keefe made clear that the $820 million mission's success was of utmost importance to the US space
agency and he called it a "double-header" following the successful Stardust mission on Friday.
That craft intercepted a comet and gathered particles in a first that could offer clues about how Earth began.
The Spirit spacecraft entered Mars' atmosphere at about 7:29pm (0329 GMT) after an approach that took the spacecraft from a top speed of 12,000mph to zero in six minutes.
To arrive intact on the planet's surface, the spacecraft had to deploy a parachute, jettison its heat shield and fire retro rockets.
The final drop of about four storeys was cushioned by giant airbags, which allowed the lander to bounce across the bleak Martian landscape for up to half a mile before coming to rest inside the giant Gusev crater.
The scientists had made final adjustments to the parachute deployment to accommodate a dust storm blowing on Mars, but found themselves on such a perfect course that they could scrap more navigation manoeuvres.
A second rover nicknamed Opportunity is expected to land on the other side of the red planet in three weeks.