On October 14, 2005, People Daily published the story on comments by
Chief Designer of the China Manned Space Program, who was interviewed
by Xinhua.
Read the article in
http://english.people.com.cn/200510/14/eng20051014_214300.html
Wang Yongzhi, the designer, is quoted as saying "We are very practical
about the manned space program. Each launch has been helpful to make
upgrades for the following one." For instance, an excessive quantity
of harmful gas was found in the first three Shenzhou vessels and it was
resolved at the Shenzhou-4 mission.