"God seven" extravehicular door airlock is the development agency developed one of the most important point of research - from here to the astronauts in space.
Extravehicular door is to meet the structural and institutional sub-system astronaut extravehicular activity while the new design is to ensure astronaut extravehicular activities critical to the success and short-term stand-alone product.
A small door, implies a lot of "mystery", but also embodies the development of a large number of staff efforts and wisdom.
How to open the door? - To the inside, outside; left open, right open; open to much angle; after astronauts wear space suits are bulky, they can easily switch freely door; in a vacuum, high temperature and other adverse conditions, door switch can not work? ... ...
Development of staff through a lot of experiments and discussion, found that: doors open outwards, although will not affect the internal space, but the vacuum pressure can affect the door's seal; the door open to the inside, it will ensure maximum sealing performance, is relatively safe choice, but how much impact will involve the issue and take up cabin space; door opening angle and the configuration of the cabin space is closely related to one door in the space can be achieved as far as to open a large, easy to ensure that astronauts , we must also consider the location of doors, the perspective of the overall impact of other equipment, the final door open "100 degree" to become the best choice on balance. In addition, for the consideration of load and pressure, the door is not flat, but slightly cylindrical arc-shaped, uniform pressure to the door, but considering the issue of carrying and use of space, the curvature of the door can not be too large, must determine the best in radians ... ...
In addition to the door itself, door-related design challenges as well.
With the "Shenzhou VI" Back bay door is different, "God seven" doors open and close in the track when in a vacuum environment, and in which the temperature may be tens of degrees below zero to zero in on the tens of degrees. Therefore, to fully consider and simulate the track high and low temperature environment of a vacuum switch doors, and sealing and switches power to detect the changes, because it will directly affect the lives of astronauts.
Door switches and door pressure point is specifically designed to ensure rapid leak sealing doors and developed.
"God seven" of the door next to the distribution of several pressure point switch, do not underestimate these small switches, they are related to the lives of astronauts, the development around them also consuming a lot of twists and turns.
Since all of the equipment must work in a vacuum environment, how to test their reliability has become a key big problem - all equipment must be vacuum in the vacuum tank simulation verification, inspection, people can not put vacuum the test tank to do the door switch, how do? Problems one by one, the development staff were "soldiers to be blocked, the water flooded soil", specially developed for this situation as a switch as the arm body out of control in vacuum tank "mechanical arm" to complete the astronauts to do unlock, open, closed, locked the door and a series of actions, the perfect solution to this problem.
How can we determine the doors close tightly it? Door quickly leak into being. It is like a responsive "security guards", through an internal sensing device, feel the pressure and temperature changes, in just a few minutes to determine the integrity of the door is closed, the astronauts sent to a "closed door Well, take off their space suits "to confirm such information.
Once, when doing reliability testing, research found the door fast weight loss at low temperatures inspection instrument failure the case of a sudden!
Development of staff is not in disarray, it was agreed that, earlier in the case of normal temperature and pressure can work, then it is clear that this failure is due to changes caused by environmental factors. According to this idea, we split up to find the source of the problem. Liu Gang, head of institutional structure subsystem "eye" that the problem lies in a ring on. The seals used in the inspection instrument fast valve on the door, this valve is widely used in aircraft, has continuously used on the spacecraft Shenzhou IV to VI, is a relatively mature product. However, the Gang know in the spacecraft development, and all the "habitual thinking" should not be - a small ring on the valve out of the question, it is difficult to accurately detect whether the door leaks, which will directly affect the astronauts back extravehicular activities of relief after the orbital module, the astronauts is deadly effects. Through repeated observation and research, Liu Gang that the Shenzhou-6 astronauts in the cabin is always state of the movement, that is, always in the atmospheric environment, and the seals at low temperatures but appeared contraction. Problem to find, research staff to re-adjust the door inspection instrument fast valve size, have also been fine-tuning of its structure, completely solved the problem.