China is gearing up for a possible final un-piloted trek of its Shenzhou spacecraft. If the flight is successful, Western experts see that country launching its first human space travelers next year.
Space authorities in China point to a Shenzhou 4 flying before year's end, perhaps indicative of a launch planned for sometime this month, said Phillip Clark, head of the Molniya Space Consultancy in the United Kingdom.
"With just about everything tested for the manned program, I would think that Shenzhou 4 will be pretty-much a duplicate of what is planned for the first manned mission. That is, test everything outbut the men," Clark told SPACE.com.
Sea landing, flight duration questions
Clark said there are two things that will be of interest on the upcoming Shenzhou 4 test hop. It is possible that a water landing of the Shenzhou return module may be slated, to evaluate an emergency sea landing system.
Also, Clark speculates that the next Shenzhou flight may be shorter than the last two spacecraft sojourns. "Shenzhou 2 and Shenzhou 3 were both seven days in duration, minus a few hours. While the Shenzhou 5 manned mission may last for a similar duration, the Chinese might want the crew down after one or three days," he said.
This thought assumes the soon-to-be-lofted craft maneuvers to a 205-mile (330 kilometer) circular Earth orbit, Clark adds, whereby landing opportunities come after an odd number of days in orbit: 1,3,5,7, etc.
"So, if Shenzhou 4 comes down after less than seven days, this could be a pointer for the duration of the first manned flight," Clark said.
Shenzhou cabin
It is still unknown outside Chinese circles whether a two-person or a full three-man crew will fly onboard a Shenzhou 5, Clark notes.
Last May, the Shanghai newspaper, the Wen Hui Bao, reported that China's first generation of astronauts --a roster of 14 candidates -- are each around 30 years of age. The astronauts are on the short side, as well as being light in weight. Those conditions are necessary to fit into the Shenzhou cabin - a snug living space just 9.2 feet (2.8 meters) long with a diameter of 7.4 feet (2.25 meters).
Clark said Chinese space officials have talked about Shenzhou being capable of flying for about three weeks of independent flight. "I think that this is 21 "man days" - 21 days with one person, 14.5 days with two men and 7 days with three men," the veteran space analyst said.
Dummy astronauts
Some space experts have wondered why Shenzhou 3's return capsule carried "dummy astronauts", rather than animals.
According to an April 5 story in the People's Daily, flying animals into orbit is not necessary. Humans in space have already returned to Earth in healthy condition, the newspaper noted.
Furthermore, the story continued, animals in a new environment could get sick, even die. "So it is hard to prove whether it is a problem with the spacecraft or the animal."
Therefore, the Shenzhou spacecraft toted a dummy astronaut experiment rather than an animal experiment. "This choice is more scientific and rational," the People's Daily reported.
Dual launch pads
In another development, Clark said that the Chinese are busy working on a second launch pad - an addition to the "manned complex" at the Jiuquan space center, and the site for all Shenzhou spacecraft liftoffs to date.
"This will allow them back-up if there is a catastrophic explosion on one pad at some time in the future," Clark said. It also means, he continued, when both pads are operational, the Chinese can then launch a Shenzhou from each pad. China would then be capable of rendezvousing and docking spacecraft in Earth orbit.
In March, Zhang Qingwei, president of the China Aerospace Science and Technology Corporation (CASC), was quoted by state-run media outlets as saying that new, more powerful launchers will boost a 20-ton permanently manned space station into orbit.
"By Western and even former-Soviet standards, the Chinese manned space program is progressing at a painfully slow rate," Clark notes. "But then again, historically, the Chinese have always taken their time with programs and have taken little notice of the expectations of those observers outside China!"
advertisement
