"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, an academician of the Chinese Academy of Sciences.

Liu, who has been engaged in space research for years, said China is not ready to kick off Moon and Mars missions simultaneously because of its national conditions and scientific grounds.

United States space agency NASA launched the first of its twin Mars rovers on June 10, rekindling worldwide interest in the planet.

Ouyang Ziyuan, a colleague of Liu, said in March that China could send its first unmanned probe to the Moon in a couple of years.

Outlining China's space activities in the 21st century, Luan Enjie, director of the China National Space Administration, said China is aiming for a landing on the Moon and participating in international activities on Mars exploration.

Luan later said the first phase of lunar exploration will be finished by 2010. But he did not disclose any timeline for the Mars program.

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

But the differences between the two explorations are greater than the similarities, suggesting the Mars probe may be years away even if the country's Moon missions are successful.

Liu insisted a pre-study of Mars exploration should proceed in spite of this, as the country has pledged to deepen its exploration and utilization of outer space.

The scientist said the probe program would consist of three stages: orbiting, landing and returning from the Mars.

The first phase of the project would see China send a Mars orbiter spacecraft to circle the planet.

This part of the mission will also deal with analyzing the space environment of Mars, according to Liu.

The subsequent two phases of the program will involve wheeled robotic explorers, which roll on the planet and collect rocks for research, and setting up an unattended station on Mars, he said.

China has long planned to obtain a more important place in the world in the field of space science, and carry out more explorations and studies of outer space, according to a policy document "China's Space Activities" issued by the Information Office of the State Council in November 2000.

(China Daily June 19, 2003)