While senior space scientists said a Mars probe was still years away, they plan to step up preparations.

"We do not have a timetable for a Mars probe program at the moment but such a project will surely benefit from the country's ongoing efforts to embark on a maiden unmanned lunar mission," said Liu Zhenxing, a space expert at the Chinese Academy of Sciences.

He said the program would consist of three stages: orbiting, landing and returning from Mars, the China Daily reported.

The first phase would see China send a Mars orbiter spacecraft to circle the planet and analyse the space environment.

The subsequent phases would involve wheeled robotic explorers to collect rocks and set up an unattended station, Liu said.

China's outlining of its lofty space ambitions follow the launch last week of the US probe Spirit toward Mars for a mission to study the geological structure of the Red Planet and try to find out if life could ever have existed there.

A second US probe to Mars is scheduled to be launched on June 26.

A European mission, Mars Express, left on June 2. A US Pathfinder rocket was the first to land on Mars in 1997.

China has made clear it wants to expand space exploration and plans a mission to the Moon within 30 months, Ouyang Ziyuan, chief scientist of the lunar exploration program, said in March.

Those comments were made just months before China is expected to send a man into space for the first time, becoming only the third country to do so after the former Soviet Union and the United States.

At the Paris air show earlier this week, a top Chinese official said China's maiden manned space flight was on track for this year.

"It will be launched by the end of this year," Liu Youguang, general manager of the space department at China Great Wall Industry Corp., said.

One or two astronauts are expected to be selected from a pool of 14 currently under training, with the help of Russia.

Ouyang told the China Daily Thursday there was no strict timeline for a Mars mission, but that the lunar probe would be crucial in pushing the program along.

"Technically speaking, the experience and expertise accumulated in the course of the lunar probe program will help China's exploration of Mars," he said.

But he stressed that the differences between the two explorations were greater than the similarities, suggesting that a Mars mission may still be a long way off even if the Moon probe was a success.

China has so far launched four unmanned spaceflights, the last of which, Shenzhou IV, successfully returned to earth in January after 162 hours in orbit seen as the final dress rehearsal before a manned mission.

The country's desire to compete in space with other world powers has taken on mammoth proportions.

Since its space program was set up in 1992 it has grown to employ tens of thousands of scientific, manufacturing and planning personnel in more than 3,000 factories.

It has been estimated that 19 billion yuan (2.3 billion US dollars) has so far been spent.

SPACE.WIRE