The three final candidates vying to be China's first astronaut in space have arrived at the spacecraft's desert launch pad, the government said yesterday, and it gave strong indications that only one will make the trip.

Xinhuanet, the Website of China's Xinhua news agency, said in a brief dispatch that the trio of finalists had arrived at northwestern China's Jiuquan Satellite Launch Center, where security is tight, Xinhua cited "informed sources."

It said the "No 1 astronaut" among them would make the flight -- the firmest indication yet that the Shenzhou V capsule will carry only one passenger.

China has scheduled its landmark first manned spaceflight for sometime between tomorrow and Friday. The craft is expected to orbit the Earth 14 times before returning.

The Xinhua report said the three finalists arrived at Jiuquan on Sunday, adding that they were to undergo final testing today.

The Shenzhou V is based on the three-seat Russian Soyuz capsule, which prompted suggestions that China might send up as many as three astronauts, or "taikonauts" as they are known in Chinese.

Outside experts and Chinese news reports say the first flight is likely to carry only one.

According to media reports yesterday, the rocket is waiting on its launch pad.

The timing of China's first manned spaceship flight is set in line with orbit conditions, the craft's need for orbital movements and working conditions, and the requirements for ground monitoring and controlling, according to a Chinese expert.

Firstly, the spacecraft should be positioned in the orbit with its solar panels facing the Sun to ensure adequate energy supply during free flight.

Secondly, an optimum angle has been selected to prevent direct irradiation of the Sun from the three infrared sensors that are used to measure the Earth while maintaining a certain temperature in the capsule.

"It is very complicated to satisfy all these requirements simultaneously when it flies in the orbit," said Zhou Jianping, chief designer of China's spaceship launch center system.

"The room is very small for locating the proper timing as climatic conditions vary in different seasons," he noted.

(eastday.com October 14, 2003)