by Morris Jones
Sydney, Australia (SPX) Jul 25, 2008
China will fly two different types of extravehicular spacesuits on the upcoming Shenzhou 7 mission. This has now been confirmed by Chinese media reports. The announcement adds a curious and unexpected twist to China's saga of planning its first spacewalk.
Over the course of 2008, Chinese media sources have struggled to explain the preparations for the spacewalk, expected in October. They have discussed various forms of spacewalking, such as tethered life support systems versus self-contained backpacks, and have also referred to dilemma of choosing between the two systems.
China has also discussed its development of an indigenous spacesuit, while exhibiting video footage of spacesuits that were clearly based on Russian designs.
Media reports such as these failed to provide a coherent picture of how China's astronauts would be dressed for the spacewalk, and confused analysts such as this author. China is well-known for its shy media relations on its space program, but the spacesuit reportage was more cryptic than usual.
This could have been a deliberate policy, designed to hide some shortcomings in the overall preparations for the mission.
In a previous article ("Shenzhou's Unsuitable Dilemma" by Morris Jones on spacedaily.com) I suggested that China was trying to select between two competing designs, but I expected that the two suits on the flight would be of the same type. It seemed most unlikely that two different types of suits would be used on the same spacewalk.
A story from the Chinese state news agency Xinhua states that "China has two types of space suits - one domestic, one from Russia" and then adds that "the taikonaut (astronaut) who would do the space walk might wear a domestic suit, designed to local standards."
A report published in Shanghai Daily adds to the story. "The suit for the space-walk astronaut on the Shenzhou VII mission was developed by Chinese scientists based on the Russian design." It then continues. "The astronaut who remains in the airlock (the Orbital Module of the Shenzhou spacecraft) will wear a Russian space suit. However, future missions will exclusively use the Chinese suits."
Piece it together, and you will see two Chinese astronauts enter the Orbital Module for the spacewalk. The suits for both astronauts will probably look almost identical. But one will be a Chinese copy of a Russian Orlan suit, and the other will be a genuine Orlan suit bought from Russia.
Why is China flying two different suits? One explanation could be that China wants to carry out a "Spacesuit Showdown", testing its own suit against the established Russian design under flight conditions.
The astronauts could compare their experiences in donning and doffing the suits, moving around in a weightless vacuum, and testing their comfort levels. Testing like this could be conducted on the ground, but nothing beats an actual mission.
An alternative explanation is that China is simply not ready or willing to fly exclusively with its own suits. This could reflect concerns over the safety of the Chinese suit, or a lack of flight-qualified suits from the manufacturer.
The Xinhua article mentions that the second astronaut, who will not leave the spacecraft, "will be there for emergencies". If this is the case, it makes sense for the potential rescuer to wear the most reliable suit, and the media statements claim he will be wearing a Russian one.
This gives cause for concern. Spacewalking is a complex and dangerous task, even for nations with years of experience. If China is making its first attempt at a spacewalk in an untrusted suit, tensions will be high. Hopefully, the two astronauts will return safe and well from this dangerous phase of the mission.
The latest media reports also contribute to the umbilical cord issue, which has been raised in previous Chinese media statements. The Shanghai Daily story claims that "the China-made suit will not have its own power system. A cord will link the astronaut with the spacecraft to provide oxygen, power and communications".
This is different from the Russian Orlan suits, which draw their life-support from self-contained backpacks. The report in Xinhua claims that "neither suit has a power system. An electric umbilical cord will link the taikonaut and the ship, providing power and information."
These reports are confusing and contradict each other. It seems evident that some form of umbilical tether will connect the Chinese spacewalker and his suit to the spacecraft, but what will be carried on this tether? It seems plausible to believe that there will be a communications link and a physical restraint to stop him floating away.
It's not clear if oxygen, power and coolant will be supplied. Each story suggests a different system. The Xinhua story, if taken literally, also suggests that the Russian Orlan suit has no power system, which is not precisely true. Orlan suits are highly independent systems. But the Orlan could be plugged into a power and communications system during the flight, as a supplement or substitute for its internal systems.
Both stories make reference to the use of exclusively Chinese-built spacesuits on future missions. This suggests that China expects to iron out any potential engineering difficulties on this mission, and then modify the design. But the final result will probably still be a suit that's a near-perfect copy of a Russian Orlan suit.
Dr Morris Jones is an Australian spaceflight analyst. Email morrisjonesNOSPAMhotmail.com. Replace NOSPAM with @ to send email. His next book, "The Adventure of Mars", will be released in August.
The Chinese Space Program - News, Policy and Technology
China News from SinoDaily.com
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