The Surveyor spacecraft fired its main rocket Thursday and went into orbit around Mars for a mapping mission intended to yield the best understanding yet of Earth's neighbor.
The success of the mission continued a new era of Mars exploration for the U.S. space agency, which plans to dispatch pairs of orbiters and landers to the red planet every 26 months.
"We are at Mars to stay," Wesley T. Huntress Jr., NASA's space science chief, said at the Jet Propulsion Laboratory.
Surveyor's engines burned 22 minutes to slow the spacecraft and place it in a 45-hour orbit around the planet. The orbit will be shrunk to two hours as Surveyor gets into position to map Mars from pole to pole.
Data collected by Surveyor is expected to create the foundation for an extended program of Mars exploration as scientists search for signs that life once existed _ or perhaps exists in hidden reaches today.
"This mission builds a vast database from which all future missions will be based," project manager Glenn Cunningham said. "It will rewrite the reference books about Mars."
Like Pathfinder, which landed July 4 and continues to radio home data and images from the dusty Martian surface, Surveyor exceeded expectations on arrival day.
"The burn was performed very close to perfectly," said Pasquale B. Esposito, navigation team chief at JPL, which manages the mission.
The engine burn began when the spacecraft was 926 miles from the Martian surface. Scientists and engineers cheered at 7 p.m. PDT, when a radar signal showed the spacecraft had completed the burn and re-emerged from a communications blackout while behind Mars.
"This really is rocket science and this team of rocket scientists have done a super job," said Claude W. "Bud" McAnally III, an official of Lockheed Martin Astronautics of Denver, the spacecraft builder.
Surveyor team members donned red baseball caps bearing the initials MGS and an embroidered slogan: "The adventure continues."
The burn slowed the spacecraft by more than 2,170 mph, down to about 9,000 mph, and placed it in elliptical orbit around Mars after a 435 million-mile journey.
Controllers had aimed the spacecraft to enter orbit at a point 186 miles above Mars' north pole.
Surveyor was designed to compile global maps of Mars, return high-resolution pictures and collect data on its atmosphere, mineral composition, interior and evolution.
Beginning Tuesday and continuing over four months, controllers planned to use aerobraking _ dipping into Mars' atmosphere and using its friction to trim an elliptical orbit to a near-circle 234 miles above the planet. Mapping begins in March.
Scientists hope Surveyor will identify the likeliest sites where life might have taken hold on the planet.
Surveyor, launched last Nov. 7 from Kennedy Space Center with spare
copies of six instruments carried by the ill-fated Mars Observer, should
be able to carry out about 75 percent of Observer's mission. Observer
disappeared just before entering orbit in August 1993.