The predicted launch time of China's first space telescope is in 2012, and will be used to observe space black holes, said the chief scientist of the program Thursday.

The Hard X-ray Modulation Telescope (HXMT) comprises three to four single telescopes equipped with hard X-ray detectors, instead of optical lenses, said Li Tipei, an academician with the Chinese Academy of Sciences (CAS).

"The detectors are much more sensitive to black holes compared with optical lenses," Li said.

The space telescope and its carrier satellite would weigh about one tonne. It was expected to enter orbit approximately 500 kilometers over the Earth's surface, and circle the Earth for four years, Li said.

The launch, which would cost 1 billion yuan (146 million U.S. dollars), had been scheduled for 2010, but it was postponed for two years due to financial problems, Li said, giving no further elaborations.

The mission was initiated by China's Ministry of Science and Technology, Tsinghua University and the CAS in 2000.

So far, the ground prototype of the HXMT is completed, with all the key technical difficulties being overcome, Li said.