LOS ANGELES, Feb.24 (Xinhuanet) -- A spacecraft designed to explore Mars in unprecedented detail from low orbit is set to fire its thrusters for Martian orbit in March, U.S. space agency NASA said on Friday.

    The mission, Mars Reconnaissance Orbiter, is expected to greatly expand the scientific understanding of Mars, pave the way for next robotic missions later this decade, and help prepare for sending humans to Mars, according to Doug McCuistion, director of NASA's Mars Exploration Program.

This artist rendering provided by NASA shows the Mars Reconnaissance Orbiter over the Martian landscape. (NASA)

    "Not only will Mars Science Laboratory's landing and research areas be determined by the Mars Reconnaissance Orbiter," he said in a statement. "But the first boots on Mars will probably get dusty at one of the many potential landing sites this orbiter will inspect all over the planet."

    Mission controllers expect a signal shortly after 1:24 p.m. Pacific time on March 10, when the mission-critical engine burn has begun. However, the burn will end during a suspenseful half hour with the spacecraft behind Mars and out of radio contact.

    The orbiter carries six instruments for studying every level of Mars from underground layers to the top of the atmosphere. Among them, the most powerful telescopic camera ever sent to a foreign planet will reveal rocks the size of a small desk.

    An advanced mineral-mapper will be able to identify water-related deposits in areas as small as a baseball infield. Radar will probe for buried ice and water. A weather camera will monitor the entire planet daily. An infrared sounder will monitor atmospheric temperatures and the movement of water vapor.

    The instruments will produce torrents of data, mission scientists expect. The orbiter can pour data to Earth at about 10 times the rate of any previous Mars mission, using a dish antenna 3 meters in diameter and a transmitter powered by 9.5 square meters of solar cells.

    "This spacecraft will return more data than all previous Mars missions combined," said Jim Graf, the project manager at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

    Scientists will analyze the information to gain a better understanding of changes in Mars' atmosphere and the processes that have formed and modified the planet's surface.

    "We're especially interested in water, whether it's ice, liquid or vapor," said Richard Zurek, a mission scientist at the JPL.

    "Learning more about where the water is today and where it was in the past will also guide future studies about whether Mars has ever supported life."

    In addition to its own investigation, a major job for the spacecraft is to relay information from vehicles working on the surface of the red planet, scientists said.

    During its planned five-year prime mission, the spacecraft will support the Phoenix Mars Scout, which is being built to land on icy soils near the northern polar ice cap in 2008, and the Mars Science Laboratory, an advanced rover under development for launch in 2009.

    However, the spacecraft will spend half a year adjusting its orbit with an adventurous process called aerobraking.

    The initial capture by Mars' gravity on March 10 will put the spacecraft into a very elongated, 35-hour orbit. The planned orbit for science observations is a low-altitude, nearly circular, two-hour loop.

    Aerobraking will use hundreds of carefully calculated dips into the upper atmosphere, deep enough to slow the spacecraft by atmospheric drag, but not deep enough to overheat the orbiter.

    It "is like a high-wire act in open air," Graf said, "the Mars' atmosphere can swell rapidly, so we need to monitor it closely to keep the orbiter at an altitude that is effective but safe." Enditem