China's lunar probe Chang'e I is expected to arrive at the apogee of more than 120,000 kilometers from the earth on Monday afternoon after its third orbital transfer after launch, according to the moon probe team. [Full Coverage]

Ultraviolet image sensors installed on the satellite will begin to work  to collect information on the earth and the moon after it enters the 48-hour orbit, Wang Yejun, chief engineer with the Beijing Aerospace Control Center (BACC) told Xinhua.

The images it collects will be transmitted back to the earth when it enters the lunar orbit, Wang said.

The satellite will start its propeller when it begins the transfer to raise its apogee from 70,000 kilometers to 120,000 kilometers, according to Wang.

Wang said the working time of Chang'e-1 engine will be longer than that in the second transfer.

Since Saturday, surveillance posts, on land and sea, and four astronomical observatories have kept watching over Chang'e-1. According to the data received so far, all systems of the satellite have been working normally.