Mikhail Kotov — about China's experience in creating a national orbital station and Russia's plans for theChina has completed the assembly of its Tiangong space station in Earth orbit.
Launched last week, the experimental module "Mengtian" successfully docked with the side port of the main module "Tianhe". The astronauts on the station, after all the checks, opened the hatch of the new module and went inside.
It is assumed that as part of three modules — "Tianhe", "Wentian" and "Mengtian" — the station will work until 2024, when it is expected to be joined by an autonomous module-the telescope "Xiongtyun". And even then, the giant telescope will not require permanent docking with the station, but will simply work in the same orbit. Only if it is necessary to carry out repairs or maintenance, it will dock to the Tiangong, where cosmonauts will take care of it.
China managed to assemble its own orbital station in orbit in just a year and a half. The creation of the modules themselves took about five years. The final size of the "Tiangong" is closest to the Soviet "World", although it is almost twice as inferior to it in weight. Of course, he is far from the International Space Station (ISS). I assume that our national orbital space station will grow in size and volume more like a Chinese "neighbor" than the ISS. That is why I propose to take a closer look at the decisions of the PRC at the stage of the formation of the Russian project.
What is known about ROS: similarities and differences with Tiangong
At the same time, if the Chinese placed the vast majority of the main functions in one basic module of the station — "Wentian", then the Russians decided to go the other way.
As expected today, the first stage of the ROS deployment will be the withdrawal of three modules. First, the scientific and energy module (NEM) will go into orbit - it was originally created to work on the ISS, but later the decision was changed in favor of the national station — it will become the basis for the ROS. By itself, the flight sample of the module is already being assembled, but since it was developed a little for other purposes, it is planned to upgrade it immediately, which will take time. As the head of the project department of RSC Energia, Yuri Elizarov, told me, the volumes of the required modernization are estimated by the organization's specialists as "small".
Following the NEM, they intend to send a node module and an airlock compartment into orbit in one bundle. Nodal is the central part of the entire orbital station, the main assembly point, to which all other elements will dock. The airlock compartment is also necessary from the very first days of the ROS operation — the crew will need many spacewalks to integrate new modules into the overall operation of the station. It is planned to complete this first stage by launching a basic module in which astronauts will live, sleep and eat. At the same time, the control functions of the ROS will be transferred from the NEM to the base module.
The second stage is expected to include other modules in the Russian station. According to the current plan, it will be two target modules and one special platform. Actually, the target ones are the scientific laboratory compartments required for setting up scientific experiments and carrying most of the payload of the station. They do not have specific names yet. Regarding the platform, Yuri Elizarov noted: "At the current design stage, we call it a service platform, because it is supposed to host robotic facilities for servicing various elements of the station."
Among the similarities between the Chinese and Russian stations, I note their compactness and unified control, unlike the ISS, where different elements are separated into different modules. I assume that the near future is precisely for such small national stations. In addition, they provide for the possibility of station conservation between visits of expeditions. It is not feasible to do this on the ISS: there must be at least one crew member for each segment — Russian and international.
As a result, Russian experts suggest the creation of ROS from a larger number of modules than China. This has its own logic. For example, such a system is more convenient for launching large modules — it will be possible to use both a heavy "Angara" and the usual "Soyuz", as it was with the delivery of the "Pier" module to the ISS (it was launched using the Soyuz-U rocket, using the version of the Progress cargo ship as the upper stage module"). Such a multi-module approach will simplify the process of assembling the station, but may increase the total time of its creation.
As for the unique Chinese telescope module, Russia has not yet planned such projects, although the idea of a large photomodule for photographing the Earth's surface has been voiced more than once in narrow circles.
Orbits and inclinations
The Tiangong station has an inclination of 41.5 degrees with respect to the Earth, which is convenient for access from China. In general, the orbit of the Chinese national station is similar to the ISS, only it is even closer to the plane of the ecliptic of our planet.
The ROS is supposed to be put into a polar orbit — this will provide the station with the ability to pass over all points of our country (and the rest of the world). The polar orbit is the most convenient for using the station as an observation point for the Earth's surface. However, at the same time, to a greater extent than, for example, in the case of the International Space Station and the Chinese National Station, astronauts will be affected by the radiation belts of the Earth. Nevertheless, most experts believe that this will not interfere with the adequate functioning of both the station itself and the people on it, if you use the ROS not in a permanent, but in a visited version. And this, in turn, poses a certain challenge for the Russian Federation — the opportunity to create and test new systems for working in space.
Placing the station in polar orbit is convenient for us because launches can be made from both the Plesetsk cosmodrome and the Vostochny one — both have launch pads for both Soyuz and Angara (and, if necessary, even a multi-launch scheme can be implemented). Russia is still a northern country, and it is geographically more convenient for it to launch into high-latitude orbits.
Thus, I come to the conclusion that the Chinese Tiangong and the planned Russian ROS (and the ISS), for all their similarity at first glance, are still quite different orbital stations. In my opinion, Russia has enough competencies to create its own national system. The PRC is perhaps worth adopting clear planning and equally scrupulous adherence to the original plan without changes and postponements. I am sure that then Russia will have an equally effective and functional creation of its own national station. The implementation of this project is still planned five years later than the Chinese one.
