NASA's Cassinispacecraft slipped through Saturn's rings and into orbit this morning as it settled in to make the most detailed study ever of the sixth planet from the sun.
Project scientists from 17 countries erupted into wild cheers when Cassinisignalled shortly after 0400 GMT that it had completed a delicate 96-minute maneuver that required the truck-sized probe to dodge through Saturn's rings and sling itself into orbit.
A European Space Agency artist's impression of Cassini at Saturn
Cassini, which travelled for seven years to reach Saturn, will spend at least the next four years studying the planet, its rings and some of its 31 known moons. Much of that time will be dedicated to Titan, one of the solar system's largest and most intriguing moons, with an atmosphere and composition that resemble a primordial Earth.
The $3 billion mission has been hailed as a model for multinational space exploration.
The Saturn mission has gone flawlessly, from Cassini's launch in October of 1997 to the end of the critical orbital insertion maneuver. The spacecraft completed the maneuver within one second of the schedule scientists had set for it more than seven years and 2.2 billion miles ago.
During Cassini's first orbit, it was expected to make its closest pass to Saturn of the entire mission and, it was hoped, send back images that could redefine man's understanding of the planet and its rings.
Cassinialso carries on its back a smaller craft, Huygens, which is designed to break away in December and plummet onto the surface of Titan for a brief study of that moon's atmosphere, which is mostly methane and nitrogen.
The probe has spent the seven years since its launch from Cape Canaveral on a circuitous interplanetary journey past Earth, Venus and Jupiter to Saturn, the sixth planet from the Sun. It will orbit Saturn at least 76 times
Scientists expect to find that Saturn has a small rocky core surrounded by a sea of liquid metallic hydrogen that bubbles like soup.