During this period propulsion research converged on integrating propulsion with airframes at high speeds, with electric/plasma propulsion concepts gaining prominence for satellite missions and conventional chemical propulsion advancing hypersonic integration. Electric propulsion, including ion thrusting and pulsed ablative approaches, highlighted ion optics, long hardware lifetimes, and robustness. Hypersonic propulsion research emphasized airframe–engine integration, high-speed combustion concepts, and nozzle acoustics, with design studies and hypersonic aircraft concept exploration guiding system-level performance. Nozzle flow control and thrust vectoring investigations addressed nonaxisymmetric and convergent-divergent configurations to evaluate installed performance, vectoring capabilities, reversing, and mixing phenomena. Across the period, propulsion efficiency and fuel conservation focused on energy-efficient propulsors and auxiliary devices to boost overall propulsion system efficiency.