After successfully launching four unmanned spaceships, China now plans to send its first manned spacecraft in the second half of 2003, the state media reported on Thursday.

Shanghai Aerospace Bureau Director Yuan Jie indicated the launch timeframe on his return to Shanghai city, after witnessing the successful launch of Shenzhou IV, the fourth unmanned spacecraft on Monday morning.

The Shenzhou IV spacecraft blasted into space with a 'long march 2f' rocket, and detached itself from the launch vehicle, entering its pre-set orbit at around noon the same day.

Preparation of the first manned spacecraft, Shenzhou V, has entered the overall assembly and testing phase, China Daily quoted Yuan as saying.

Officials said the first batch of Chinese astronauts, all fighter pilots, had entered the spacecraft to receive training for the first time.

The launch of Shenzhou IV is the second time in a year that the country has staged an unmanned mission, following the launch of Shenzhou III nine months ago.

Compared to the three previous unmanned space capsules launched between November 1999 and March 2002, Shenzhou IV represents China's most sophisticated and fullest preparation so far to realise the nation's long-cherished dream of manned space flight, said Yuan.

Sources from the Beijing aerospace command and control centre said all experiments carried on Shenzhou IV had been sucessful.

On Monday morning, it sent back a clear New Year's greeting to the whole nation, the first of its kind by the spacecraft, Xinhua news agency reported.

The Shenzhou IV is expected to return to earth after completing all the planned scientific experiments, including some involving the astronaut flight system, control of the spacecraft environment and life support sub-system, the commander and chief designer of the space application system, Gu Yidong said.

If China succeeds in sending a manned space mission, it will become the world's third country to independently launch a human into the space, following the former Soviet Union and the United States.