The Shenzhou V, or Divine Vessel V, is expected to take off in the days following October 14 and will orbit the earth at least 10 times in a flight lasting less than 24 hours, said Chen Lan, curator of the Go Taikonauts! website.
"The launch cannot come before October 14 because Chinese leaders will be attending an important meeting in Beijing and I believe some of them, like (former president and military strongman) Jiang Zemin, will want to be at the launch site to witness the launch," Chen told AFP.
Chen, whose website has accurately monitored China's space program and satellite launches since the 1990s, added that the weather and other technical matters could influence the final launch date.
"If the weather is not just right or if they have any technical problems then for sure the launch date will be moved back," he said.
On his website, Chen has posted a list of China's 14 astronauts and predicts that either Li Qinglong or Wu Jie, two pilots who have trained in Russia's space program, could be selected to man the historic flight.
Other Chinese astronauts hoping to be China's first in space include Chen Quan, Deng Qingming, Fei Junlong, Jing Haipen, Liu Buoming, Liu Wang, Nie Haishen, Pan Zhanchun, Yang Liwei, Zhai Zhigang, Zhang Xiaoguan, Zhao Chuandong.
Chinese space officials have indicated that the Shenzhou V pilot will be selected on the morning of the flight from a pool of three or four astronauts that have already been named.
Criteria will include psychological and physical make-up on the morning of the launch.
Chen said he doubted that more than one astronaut would fly on the Shenzhou V, despite the space capsules's three man capacity.
"It is almost sure that only one astronaut will fly in Shenzhou V, but if the flight is completely successful, then I'm pretty sure that at least two astronauts will fly on Shenzhou VI in a flight that could come within six months," Chen said.
Since Shenzhou I flew its maiden unmanned voyage in 1999, space experts have speculated that the first manned flight could include more than one astronaut due to the size of the space capsule.
Such a flight would put China technically ahead in initial phases of both the former Soviet Union and the United States, who as the only other nations to put humans in space first flew solo missions.
Besides putting its first astronaut in space, the Shenzhou V would also carry out some scientific and earth sensing experiments before landing in the deserts of Inner Mongolia, Chen said.