NASA's Odysseyspacecraft slipped into orbit around Mars overnight, 200 days after it left Earth at a speed of more than 13,000 mph to search for signs of water on the red planet.
Relieved NASA scientists - who saw their last two missions to Mars both end in failure - burst into cheers and exchanged hugs at the Jet Propulsion Laboratory in Pasadena after the spacecraft signaled it had successfully reached orbit.
Odyssey, a box-shaped craft designed to spend over two years circling Mars to study its climate and geologic history, was launched in April as NASA's first trip to the fourth planet from the Sun since two failed missions in 1999.
The craft's entry into Mars orbit was the moment of greatest risk for the 300 million project, though scientists conceded their job was far from over.
Odysseyis expected to begin its primary mission in January, when it will use various scientific instruments to study the chemical and mineral composition of the red planet.
It is also expected to serve as a radio relay and provide communication support for upcoming missions designed to send landers and rovers to Mars. Goldin said those missions would pave the way for man eventually landing on the planet.