The expansion of space exploration requires the development of sufficiently powerful and reliable power facilities which can operate for a long time. Such facilities could be nuclear power systems and nuclear-powered propulsion systems with turbomachine energy conversion. The development of such systems at the present time is based on the results of work performed as part of the nuclear rocket motor program. The data presented in this article attest to the fact that our country plays a leading role in the construction of such of reactors. To maintain our leading position in space nuclear technologies, it is important to use and further develop the existing unique engineering and technological bases.The expansion of the scales and forms of space activity, the increased complexity of the problems solved by space means, the growing need for increasing the power of propulsion for operations in space, and the active service life of space vehicles make it vital to use atomic energy. In contrast to solar systems, space nuclear power systems do not depend on the orientation of the space vehicle and the distance to the sun. Nuclear power systems with electric power above 50 kW have higher specific mass and power, larger dimensions in the transport and deployment positions, better dynamical properties, radiation resistance and other characteristics than solar systems.The advantages of nuclear energy sources guarantee that they will play a chief role in the development in the future of transport-energy modules for near-Earth and interplanetary vehicles and interplanetary bases. The work performed in these directions will in many ways determine the prospects for developing space technologies, and their possibilities for solving scientific, defense, and socioeconomic problems.The 50-year history in using nuclear energy for assimilating space is characterized by the development and successful testing on Earth and in space the nuclear thermionic and thermoelectric energy systems SP-100 (USA), Romashka, BUK, Topaz, and Enisei (USSR) as well as isotopic systems in both countries. Our country is the only one in the world which possesses experience in developing, preflight preparation, and operation of nuclear power systems. We have conducted more than 30 launches of such systems into near-Earth orbits.In the 1950s, the USSR and the USA began work on nuclear rocket motors (NRM). In contrast to the American design, our concept of such motors provided for a heterogeneous structure of the NRM reactors, which made it possible to perform autonomous, using less money and time, development of the components of the core, including the most distressed fuel elements and fuel assemblies. Unique research reactors IGR and IVG-1, located on the Semipalatinsk test site, are being developed to test these systems according to the designs developed at the Research and Design Institute of Electrical Technology together with specialists from the I. V. Kurchatov Institute of Atomic Energy and PNITI. The first one -a heat capacity type reactor -was put ...
