In our country, the development of a transport and energy module TEM with a nuclear power plant of a megawatt class (NPPU) continues. The appearance of such a model suitable for operation will have a serious impact on the further development of domestic and world cosmonautics. In the meantime, TEM is at the stage of design work, and recently the public was again shown a model of such a product in its current form.
Exhibit MAKS-2019
In recent years, various materials on TEM and NEP for it have been repeatedly published. Among other things, the developers showed drawings with the possible appearance of such a sample. At the end of August, within the framework of the MAKS-2019 salon, the first demonstration of the new TEM layout, reflecting the current views on this project, took place. The model was present in the Roscosmos pavilion at the Arsenal KB stand.
The current version of the TEM design differs markedly from the previously demonstrated versions, but retains certain features. In particular, the general provisions of the assembly of units and approaches to design have been preserved. At the same time, there are a number of characteristic differences.
The largest element of the breadboard module is a telescopic four-section truss with a circular cross-section, which is the basis for assembling the units. Its head is equipped with a conical truss and a closed compartment. On the sides of the truss are six cooling panels. The tail section of the TEM is made in the form of a closed rectangular body. The main truss is fixed on it in front, solar panels are on the sides. The hull accommodates a new type of rocket engine and other units.
New and old
Previously, in publications on the topic of TEM and nuclear power propulsion systems, images with equipment of a different look appeared. According to one of the later versions of the project, the transport-energy module should be based on a longitudinal sliding truss with a square cross section and a large elongation, which facilitates the launch of the product into orbit. A compartment with a reactor is placed in its head section, an electric rocket engine and other systems placed on deployable supports in the tail section. It was planned to place cooling equipment along the supporting truss.
The layout from KB "Arsenal" has a number of characteristic features and differs from older images. First of all, it is distinguished by the design of the main truss and the layout of the units. The new version of the TEM is characterized by a more massive load-bearing truss of a different design. He also lost the X-shaped tail booms, deployed in flight and carrying some of the instruments.
The design of the layout allows for a change in layout. Perhaps now the large tail body contains not only an electric rocket engine, but also a nuclear reactor with accompanying systems. In this case, the smaller head body can be used to accommodate control systems or other equipment.
Different diagrams previously featured different cooling system configurations. The same applies to the new layout. This time, to radiate excess heat into the space, it is proposed to use six panels-emitters installed along the truss in the form of three parallel "planes". Previously, other cooler configurations were offered, incl. aggregates of a larger area, occupying almost the entire length of the supporting truss.
In November last year, the Roskosmos television studio published a video showing the possible appearance of a future TEM with a nuclear power plant. This version of the module was seriously different from those demonstrated earlier. While retaining the linear architecture based on a sliding truss, such a TEM had to have tail units made in the form of an open cylinder. In this form, the power plant, cooling, etc. should have been performed.
It is easy to see that the current layout of the TEM also differs from the "last year" version of the look. At the same time, in appearance and design, it is much closer to earlier versions of the project.
Technical challenges
The TEM project is distinguished by the highest technical complexity and for its successful implementation it is necessary to solve a lot of special problems. To create such a module, new designs of components and assemblies, new technologies and materials with special characteristics are needed. The need to solve all these problems has led to the fact that the development of nuclear power plant and TEM is carried out by a number of enterprises from Roscosmos and Rosatom.
At different times, the published materials contained different versions of TEM, and the reason for this can be considered precisely the general complexity of the project. Success in finding solutions to certain problems led to corresponding changes in the overall appearance of the module. Accordingly, the latest layout of the TEM from KB "Arsenal" shows the current views on the project.
According to known data, a gas-cooled fast-neutron nuclear reactor was chosen as the basis for the nuclear power plant. A helium-xenon mixture will be used in the first circuit of the cooling system. Fuel with an increased degree of enrichment will be placed in the core. The core temperature will reach 1500 ° K. It is planned to provide the highest design resource, allowing the TEM to operate for 10-12 years.
Nuclear power plants of this kind and with such characteristics have not yet been created or operated. For the construction of such a structure, materials with high resistance to thermal and mechanical stress are required. It is also necessary to work out the design itself so that, with the required power, it has acceptable dimensions and weight.
There are difficulties in the field of cooling systems. A nuclear power plant of a megawatt class must dissipate comparable volumes of thermal energy into space. Modern radiators for space technology cannot yet boast of such characteristics. So, the ISS cooling system drops into space approx. 70 kW of thermal energy is several times less than that required for the nuclear power plant and TEM.
Different variants of coolers for TEM are being worked out, which is reflected in the figures and during the assembly of the models. Apparently, the set of flat radiators on the layout from Arsenal is currently considered the most profitable design with optimal characteristics. However, it is quite possible that this system will not be the final version.
Despite all the difficulties, noticeable successes have been achieved within the TEM project. So, a few years ago, tests began on the ID-500 electric rocket engine, created specifically for the future nuclear power plant. In 2017, such a product worked at the stand for 300 hours, showing a power of 35 kW.
The assembly and testing of individual components of the nuclear power plant and TEM are carried out on a regular basis. For example, a prototype drip cooling system was tested last year. Other components of the reactor, auxiliary systems and the transport and energy module as a whole are being tested.
Transport of the distant future
The aim of the current projects of nuclear power plant and TEM is to create a promising complex capable of solving new problems in outer space. The transport and power module with a reactor and an electric rocket engine will have important advantages over rocket systems of traditional designs and will make it possible to successfully organize new missions.
The main sphere of TEM application is considered to be flights to other celestial bodies. The NPP shows the highest fuel efficiency and has a unique specific impulse, which simplifies flights to the Moon or Mars. It also becomes possible to increase the payload in comparison with the current rocket and space systems. An important feature of the TEM is the ability to supply power to the load using the standard means of the module.
However, obtaining such results is possible only in the distant future. According to current plans, flight tests of the TEM in full configuration will begin no earlier than the end of the twenties. The start of operation and the involvement of the module in real work are possible only in the early thirties.
TEM work will continue for several more years, and during this time the project may undergo noticeable changes. In this regard, it can be assumed that the layout of the module for MAKS-2019 will soon cease to reflect the real appearance of the product being created. However, a change in views on the structure and its elements will lead to the emergence of new demonstration materials - already at the next exhibitions.
