Russian cosmonauts Alexander Misurkin and Anton Shkaplerov on February 2 went into space on the program of the Russian segment of the ISS to replace the receiver on the antenna module Zvezda. Shkaplerov works in "Orlan-MK", and for Misurkin - this is the first exit in the new version of the "Orlan-MKS" spacesuit.
What is different about the new spacesuit, what are the features of the preparation for the exit, why are the suits dry and how does the person "fight" with them, said Dmitry Zubov, the head of the Moscow Cosmonaut Training Center near Moscow.
New cooling system
According to Zubov, in the name of the new "Orlan" the ISS prefix stands for "modernized computerized synthetic", in this space suit there are two main differences. First of all, this is a new design of hoses and pants, where a more reliable type of material based on polyurethane is used
"The second is the integration into the suit of the refined cooling system of the operator. Previously it was manually operated, now it has become automatic," the head of the department said. The cosmonaut does not need to independently set the water temperature in the cooling system with a mechanical switch, the system does this automatically, depending on the intensity of the work.
Work in a spacesuit, the expert explained, is a heavy physical labor, as the suit is under pressure and a person constantly overcomes the resistance of his soft shells when bending arms and legs, one might say, is struggling with it.
The electronic unit
The Orlan-MKS reconfiguration also went through the spacesuit operator's console - the chest unit, where, in particular, the control elements of the suit's microcomputer and the display are located.
"It (the display) has become larger than the previous version, thus increasing the size of the inscriptions, which will make it easier to read the information, which indirectly affects both the efficiency and safety of the cosmonauts," Zubov said.
According to the expert, control functions have also been added - now you can use the special toggle switch to select the cooling system operation mode (automatic or manual).
As in the thermos
Under the main spacesuit before the departure, the cosmonauts wear a blue mesh suit with plastic tubes interwoven into it. This internal suit has a special connector for connection to the cooling system, cold water circulates in its tubes during operation. Due to contact with the surface of the body, the suit removes excess heat from the cosmonaut, which is taken to space through a special device.
The expert explained that regardless of whether astronauts work in the shade or in the sun, the task of a spacesuit is to isolate the internal volume from a person from heat inflows from outside and, conversely, from heat transfer from within. "Inside the suit there is a package of thermal insulation, the thermos effect is obtained - the heat transfer from the outside to the inside and vice versa is minimal," he said.
How to prepare for the exit
Usually the preparation for the exit starts in 10-12 days. The astronauts check the spacesuits, in particular, on the tightness, install on them all replaceable elements - oxygen reserves, a battery pack. After that, the cosmonaut puts on a spacesuit to fit to his size (space suits are universal and can be used by people with a height of 165 to 190 cm).
"There is such an operation - fitting, that is, exhibiting its dimensions by changing the length of the soft shells of the spacesuit - the sleeves and the pants." During the exit, the cosmonaut is in the suit up to ten hours, and in the loaded state, under pressure, there are sufficiently rigid elements in the spacesuit. If the suit does not correspond to the anthropometry of the operator, the cosmonaut simply will not be able to work effectively in it - all mobile elements will be displaced relative to the human joints, "Zubov said. In parallel, the cosmonauts carefully study the materials on operations that will be conducted overboard, equipment and tools are being prepared.
The CPC expert noted that the preparations for the exit took a long period not only because of the large number of stages, but also because of the space workloads of daily duties. "There are a lot of tasks at the station - daily operations, experiments, so the preparation is divided into blocks - every day for two or three hours," he said.
Do not forget to dry off sweat and water
After the release, the cosmonauts carry out maintenance of the spacesuits and "canned" until the next application, it takes about two days. For example, you need to remove all elements that have exhausted the resource
He explained that in the process of work, the cosmonaut makes quite a lot of effort, "and like all normal people he sweats, and this sweat on contact with the shells on the elements remains." "Also, the atmosphere in the spacesuit can be wet at some stages, and condensation occurs at large temperature changes. All this condensation and moisture must be removed during storage so that in the future this does not affect the condition of the elements of the spacesuit, so that they do not corrode so that they do not it was mold or plaque, which could lead to malfunctioning, "he said.
How long can I live in a spacesuit?
Now the equipment of a spacesuit allows a person to be inside for ten hours - from the time he was sealed up to the moment when he took off his helmet.
The work during the exit is planned as follows: an hour and a half is spent on sluicing before leaving (the cosmonaut is already in the spacesuit, but the entrance hatch is closed), then there is an extra-flying activity of about six hours (this time is considered optimal by experts in terms of performance). After the exit, the cosmonauts return to the airlock compartment, close the hatch and compare the pressure for 30 minutes.
"So, we have about eight hours of work time, and we leave two hours for contingencies: if something went wrong and we need to stay, or we need to stay and finish some work at the exit, we have the opportunity extend the work time due to this resource, "- said Zubov.