Th e subject of this paper is to substantiate the selection of the solid rocket propellant type and grain geometry for the sustainer motor
of an operational-tactical missile. Th e paper presents a classifi cation of solid propellants (single-base propellants, homogeneous,
heterogeneous, and modifi ed double-base propellants) and their physicochemical and ballistic characteristics. A comparative
analysis of typical formulations is performed with respect to specifi c impulse, density, smoke signature, crack resistance, and
manufacturability. Based on the requirements imposed on operational-tactical missile systems (operating temperature range,
storage life, launch signature constraints, and production capabilities), the advantages of heterogeneous composite propellants based
on HTPB/AP are justifi ed as a balanced solution providing high energetic performance, mechanical reliability, and manufacturing
feasibility. We also consider alternative propellant options (XZDB, CMDB, ADN-based formulations) for applications requiring
higher low-smoke constraints or specialized thrust profi les. Based on the above, proposed recommendations for selecting the grain
geometry (cast-bonded grains, end-burning, tubular, and slot-channel confi gurations) depend on the required thrust-time profi le
and structural constraints.