An annular ablative gas blocking device provides for automatic altitude compensation of a rocket engine exhaust plume. The nozzle is over expanded at low level launch altitudes and near optimally expanded at the highest altitude at the terminal burnout or staging altitude of the rocket engine. The ablative gas blocking device in the nozzle exit mitigates low altitude launch effects of an over expanded nozzle and inhibits external atmospheric air entrance into the nozzle at launch. The gas blocking means ablatively erodes away from plume impingement as the rocket ascends in a pre-programmed manner to achieve optimum area expansion ratio at all altitudes.

A modulation device for modulating a gas ejection section, the device being for placing in a nozzle upstream from the throat of the nozzle, the modulation device including a plug having a downstream end forming a member for partially obstructing the nozzle throat; and a plug guide having an internal housing in which the upstream end of the plug is present. The upstream end of the plug is suitable for sliding in the internal housing of the plug guide between a first position in which the upstream end of the plug is present in an upstream portion of the internal housing, and a second position in which the upstream end is present in a downstream portion of the internal housing. The upstream end of the plug is held in the first position by at least one retaining element for breaking under the effect of heat.

A nozzle (1) for a space vehicle engine (M), the nozzle comprising a stationary portion (2) and a movable portion (3), the nozzle (1) including a pneumatic deployment system (4) comprising: a deployment actuator (5) for deploying the movable portion (3) of the nozzle (1); a high unlocking actuator (6); a low unlocking actuator (7); and an ejector (41); the deployment system (4) including a feed system (8) configured so as to, sequentially: move the deployment actuator (5) from its support position towards its deployment position; move the high and low unlocking actuators (6, 7) into their high and low unlocking positions; and actuate the ejector so as to eject the deployment system (4) from the nozzle (1).

A rocket motor for a gun-fired projectile is configured stiffen the burnable propellant in the rocket motor during burning and/or protect the rocket motor from the pressure that occurs during firing of the projectile from the gun. The rocket motor may include a rigid structure that is integrated into the burnable propellant grain to stabilize the burnable propellant grain during burning of the burnable propellant grain. The rigid structure has a matrix or truss-like shape that extends into the depth of the burnable propellant grain. The rocket motor may include a baffled end cap that covers a nozzle of the rocket motor. The end cap defines a baffled path through the end cap to dampen gas flow into the nozzle and prevent particles of the gun propellant from entering the rocket motor. A rocket motor may implement the rigid structure or the baffled end cap, or both structures.

A liquid rocket engine assembly comprising a thrust chamber, a nozzle, and a joint structure. The joint structure attaches the thrust chamber and the nozzle and comprises at least one seal element and an attachment ring interposed between the thrust chamber and the nozzle. Fasteners extend between the nozzle and the thrust chamber through the at least one seal element and the attachment ring. Materials of the thrust chamber and of the nozzle comprise different coefficients of thermal expansion. A method of forming a liquid rocket engine assembly is also disclosed.

A liquid rocket engine assembly comprising a thrust chamber, a nozzle, and a joint structure. The joint structure attaches the thrust chamber and the nozzle and comprises at least one seal element and an attachment ring interposed between the thrust chamber and the nozzle. Fasteners extend between the nozzle and the thrust chamber through the at least one seal element and the attachment ring. Materials of the thrust chamber and of the nozzle comprise different coefficients of thermal expansion. A method of forming a liquid rocket engine assembly is also disclosed.

A liquid rocket engine assembly comprising a thrust chamber, a nozzle, and a joint structure. The joint structure attaches the thrust chamber and the nozzle and comprises at least one seal element and an attachment ring interposed between the thrust chamber and the nozzle. Fasteners extend between the nozzle and the thrust chamber through the at least one seal element and the attachment ring. Materials of the thrust chamber and of the nozzle comprise different coefficients of thermal expansion. A method of forming a liquid rocket engine assembly is also disclosed.

A flexible bearing assembly includes at least one metal end ring, a flexible bearing core having a plurality of layers of a resilient material between layers of a reinforcement material, and a phenolic composite material between and bonded to each of the at least one metal end ring and the flexible bearing core. A rocket motor assembly includes a chamber configured to contain a propellant and a movable thrust nozzle coupled to the chamber. The movable thrust nozzle includes a phenolic composite material between and bonded to each of a metal end ring and a flexible bearing core. Methods of forming a flexible bearing assembly include bonding a phenolic composite material to at least one metal end ring and bonding a flexible bearing core to the phenolic composite material. The flexible bearing core includes a plurality of layers of a resilient material between layers of a reinforcement material.

A rocket throat insert including an annular body having a radially inner annular wall portion and a radially outer annular portion. The inner wall portion has a contoured radially inner surface defining a nozzle throat. The outer portion includes an annular buttressing structure supporting the inner wall portion and defining one or more insulation gaps arranged annularly around the inner wall portion. The insulation gaps restrict the radial flow of heat through the annular body.

A modulation device for modulating a gas ejection section, the device being for placing in a nozzle upstream from the throat of the nozzle, the modulation device including a plug having a downstream end forming a member for partially obstructing the nozzle throat; and a plug guide having an internal housing in which the upstream end of the plug is present. The upstream end of the plug is suitable for sliding in the internal housing of the plug guide between a first position in which the upstream end of the plug is present in an upstream portion of the internal housing, and a second position in which the upstream end is present in a downstream portion of the internal housing. The upstream end of the plug is held in the first position by at least one retaining element for breaking under the effect of heat.