This monograph recounts and details the development of a nuclear rocket engine reactor (NRER). In particular, it explains the working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, and high-energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K. The design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials such as carbide and uranium...