China's first lunar orbiter is doing well in space and expected to reach its moon orbit at 11:25 am on Monday, the China National Space Administration (CNSA) said yesterday.

"All systems onboard are currently in excellent condition and the spacecraft is on its expected trajectory. One or two trajectory adjustments will be made during the next few days," CNSA spokesperson Pei Zhaoyu told a press briefing in Beijing.

Of the three planned orbital corrections, the first was scheduled at about 10:30am yesterday, but was cancelled "because Chang'e I has been operating well on the expected trajectory," Tong Bin, deputy chief engineer of the Beijing Aerospace Control Center (BACC), said.

The first orbital correction was re-scheduled for today, Wang Yejun, chief engineer of the BACC, said.

"The BACC will issue instructions to Chang'e I to ignite two small engines today and slightly modulate its trajectory, in a bid to guarantee it travels on the preset orbit," Wang said.

A second orbital correction might be carried out on Sunday, he said.

The BACC collaborated with the European Space Agency (ESA) yesterday to observe and control Chang'e-1 and all information received from ESA's tracking station network showed the orbiter was operating normally.

"This was the first time the BACC had cooperated with an international body to control Chang'e-1, and it will enhance our preciseness in further controlling the satellite," Wang said.

After the probe enters the moon's orbit, it will brake several times so it can be captured by lunar gravity and become a real circumlunar satellite.

Chang'e-1 completed its fourth orbital transfer late on Wednesday afternoon, shifting out of its 120,000-km orbit around the Earth and moving toward a 380,000-km circumlunar orbit on Monday.

"The orbit transfers have been a success with minimal effort and the satellite has performed exactly as expected," Sun Zezhou, deputy chief designer of Chang'e I, said.

He said orbit designs for the satellite were completed domestically, with the China Academy of Space Technology (CAST) at the core of a massive team of educational and research institutions, including the National University of Defense Technology, the BACC and the Shanghai Observatory.

Chang'e I cost 1.4 billion yuan (US$187 million) to build, Sun said - about the cost of 14 km of expressway.

China's goals, both engineering and scientific, for its lunar exploration activities are completely peaceful, Pei said.

He stressed the openness of the Chang'e project, and said it had been open to the public since its very first phases.

(China Daily November 2, 2007)