China has steadily built up expertise in designing and operating the spacecraft, booster rocket, and in running ground operations. The country has flown four unpiloted test flights of a similar craft since 1999.

• Nov. 19-20, 1999: 21-hour voyage
• Jan. 9-16, 2001: 7 day flight
• March 25-April 1, 2002: 7 day flight
• Dec. 29, 2002 - Jan. 5, 2003: 7 day flight

The crew cabin for two of the tests, Shenzhou 3 and Shenzhou 4, housed specially outfitted mannequins that radioed back simulated heartbeats, breathing rates, and other vital signs. Size of the entry/descent module should allow up to three passengers, although it is possible that Shenzhou 5 will be flown solo.

To date, there appears to have been one early problem. Shenzhou 2's reentry cabin may have been severely damaged on landing. Speculation is that the module may have crashed due to a parachute problem. [ Overview of China's space program ]