A rocket booster has an annular shape, with a casing defining an annular space therewithin, and a solid rocket fuel in the annular spacing. The rocket booster also includes one or more nozzle pieces, mechanically coupled to the casing, that define one or more nozzles at the aft side of the rocket booster. The rocket booster may be mechanically coupled to an object protruding from the back of a fuselage of a flight vehicle, such as a missile. For example, the rocket booster may be placed around an aft turbojet nozzle of the flight vehicle. This allows the rocket booster to be used in situations where primary propulsion must be running both before and after (and perhaps during) the firing of the rocket booster.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

A combustion chamber including a diverging portion. The combustion chamber extends along a longitudinal axis and includes a fluid injection system from which there extends in a downstream direction a wall presenting a throat and a diverging portion situated downstream from the throat. The chamber further includes a tubular element surrounding the wall at least in part and configured to take up most of forces generated during operation of the chamber on the downstream end of the wall to transfer the forces to a structure situated upstream from the chamber.

A combustion chamber including a diverging portion. The combustion chamber extends along a longitudinal axis and includes a fluid injection system from which there extends in a downstream direction a wall presenting a throat and a diverging portion situated downstream from the throat. The chamber further includes a tubular element surrounding the wall at least in part and configured to take up most of forces generated during operation of the chamber on the downstream end of the wall to transfer the forces to a structure situated upstream from the chamber.

According to one contemplated embodiment of the rocket engine invention, water is first pumped from a water tank through a rocket nozzle cooling heat exchanger wherein it is evaporated into said superheated steam. A generator supplies electricity to an electrolyzer that electrolyzes superheated steam into gaseous hydrogen and gaseous oxygen. The gaseous hydrogen and gaseous oxygen is employed for forming an annular curtain of secondary combustion in a divergent rocket engine. The secondary combustion gas surrounds a central thrust of combustion gas produced in an upstream combustion chamber by a primary injection of hydrogen/oxygen supplied from a liquid hydrogen tank and liquid oxygen tank. The rocket liquid hydrogen tank and liquid oxygen tank are pressurized by gaseous hydrogen and gaseous oxygen generated by the electrolyzer.

According to one contemplated embodiment of the rocket engine invention, water is first pumped from a water tank through a rocket nozzle cooling heat exchanger wherein it is evaporated into said superheated steam. A generator supplies electricity to an electrolyzer that electrolyzes superheated steam into gaseous hydrogen and gaseous oxygen. The gaseous hydrogen and gaseous oxygen is employed for forming an annular curtain of secondary combustion in a divergent rocket engine. The secondary combustion gas surrounds a central thrust of combustion gas produced in an upstream combustion chamber by a primary injection of hydrogen/oxygen supplied from a liquid hydrogen tank and liquid oxygen tank. The rocket liquid hydrogen tank and liquid oxygen tank are pressurized by gaseous hydrogen and gaseous oxygen generated by the electrolyzer.

A screw rocket nozzle may include a disc shaped nozzle body and a spiral flow path having an inlet and an outlet. In some examples the flow path is radial with the inlet positioned at a higher pressure region than the outlet.

A screw rocket nozzle may include a disc shaped nozzle body and a spiral flow path having an inlet and an outlet. In some examples the flow path is radial with the inlet positioned at a higher pressure region than the outlet.

A rocket engine nozzle includes an aerospike having a plurality of adjustable airfoil vanes distributed around a central longitudinal axis of a rocket engine combustion chamber. The aerospike is integrated on an exit plane at an exit end of the combustion chamber. The adjustable airfoil vanes and an inner perimeter of the combustion chamber define a plurality of apertures which choke an exhaust exiting the combustion chamber and cause the exhaust to expand supersonically along the adjustable airfoil vanes, creating a supersonic jet. An actuator is configured to adjust a position of each of the adjustable airfoil vane relative to each other so as to direct the exhaust exiting the rocket engine combustion chamber as the exhaust expands supersonically over the airfoil vanes without causing a shockwave to be imparted on the supersonic jet that is created. Accordingly, performance of the rocket engine is improved over conventional systems.

A rocket engine nozzle manufacturable and applicable to tactical missile designs includes an aerospike having a plurality of airfoil fins distributed around a central longitudinal axis of a rocket engine combustion chamber. The aerospike is integrated on an exit plane at an exit end of the combustion chamber. The airfoil fins and an inner perimeter of the combustion chamber define a plurality of apertures which choke an airflow exiting the combustion chamber and cause the airflow to expand supersonically along the airfoil fins. The aerospike rocket engine nozzle requires less machine precision and achieves packing benefits over conventional bell and aerospike nozzle geometries. The configuration of the aerospike rocket engine nozzle also removes the producibility and heating constraints typically encountered with conventional aerospike nozzles in tactical missile applications while improving thrust performance of the rocket engine across a wide range of altitudes.