NASA's Mars orbiter approaches planet

NASA engineers are preparing for the Mars Reconnaissance Orbiter to make its risky approach to the planet on March 10.

"It's going to be difficult to get it into orbit," Doug McCuistion, the head of NASA's Mars Exploration Program told a briefing on Friday. "Mars is hard, Mars can be unpredictable, but we've got a good team."

The probe will collect data on the planet's weather and look for signs of water, a requirement for Earth-type life.

Scientists will also use the information to plan future landings of other spacecraft.

NASA has a 65 per cent success rate at getting probes to orbit Mars, compared to 80 per cent for successful landings on its surface.

As it approaches the planet, controllers on Earth anticipate there will be a signal from the spacecraft indicating that a 27-minute engine burn will slow it down and let martian gravity capture it.

Mars Reconnaissance Orbiter has flown for nearly 483 million kilometres since its launch on August 12, 2005.