An augmented aerospike nozzle includes a throat, a centerbody extending aft of the throat, an inner expansion surface defined by the centerbody, an outer expansion surface outboard of the inner expansion surface, and an expansion cavity defined between the inner expansion surface and the outer expansion surface. An engine includes a high pressure chamber and the augmented aerospike nozzle. A vehicle for supersonic flight includes the engine with the augmented aerospike nozzle.

A center plug includes an inner skin, the inner skin extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead connected to and extending radially outward from the inner skin; and an acoustic panel, the acoustic panel including a first sheet having a first plurality of perforated walls and a first plurality of non-perforated walls, a second sheet having a second plurality of perforated walls and a second plurality of non-perforated walls, the first sheet being sandwiched together with the second sheet to form an N-shaped structure having a combined plurality of perforated walls and a combined plurality of non-perforated walls.

A variable area nozzle assembly includes a fixed center plug, a fixed outer nozzle, and an inner nozzle. The fixed center plug includes a seal. The inner nozzle is disposed between the fixed center plug and the fixed outer nozzle. The inner nozzle includes an inner nozzle body. The inner nozzle body forms a primary duct between the inner nozzle and the fixed outer nozzle. The inner nozzle body forms a secondary duct and a gap. The gap is a nozzle outlet of the secondary duct. The secondary duct is disposed between the inner nozzle body and the fixed center plug upstream of the seal. The inner nozzle body forms a plurality of apertures. The inner nozzle body is translatable between a first position and a second position. In the first position, the primary duct has a first cross-sectional area and the plurality of apertures are isolated from the gap by the seal. In the second position, the primary duct has a second cross-sectional area and the plurality of apertures are connected in fluid communication with the gap.

An aerospike nozzle for an upper stage rocket of a multi-stage rocket system includes a throat, a centerbody extending aft of the throat, and an expansion surface defined by the centerbody, wherein the centerbody is an annular aerospike having a base that at least partially defines an aft end of the upper stage rocket. An engine includes a high pressure chamber and the aerospike nozzle. A vehicle for supersonic flight includes the engine with the aerospike nozzle.

A center plug includes an inner skin, the inner skin extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead connected to and extending radially outward from the inner skin; and an acoustic panel, the acoustic panel including a first sheet having a first plurality of perforated walls and a first plurality of non-perforated walls, a second sheet having a second plurality of perforated walls and a second plurality of non-perforated walls, the first sheet being sandwiched together with the second sheet to form an N-shaped structure having a combined plurality of perforated walls and a combined plurality of non-perforated walls.

A modulator device for modulating a gas ejection section, which device is for placing in a nozzle upstream from the throat of the nozzle and includes a plunger. The plunger has both a proximal portion connected to a control guide and also a distal portion in the form of a body of revolution, the plunger being movable between a retracted position and an extended position. The plunger presents, in its distal portion, a first section of concave shape and a second section of concave shape situated downstream from the first section.

A vane assembly may comprise an engine case and an anti-rotation lug coupled to the engine case. The anti-rotation lug may have a forward end and an aft end. A vane cluster may be supported within the engine case. The vane cluster may include an outer shroud with a first slot defined by a forward flange of the outer shroud and with a second slot defined by an aft flange of the outer shroud. The second slot may be configured to receive the aft end of the anti-rotation lug from first direction and wherein the aft flange may be configured to block receipt of the anti-rotation lug from a second direction, which is opposite the first direction.

A center plug includes an inner skin, the inner skin extending along an axial centerline; an outer skin positioned radially outside the inner skin; a forward bulkhead connected to and extending radially outward from the inner skin; an aft bulkhead connected to and extending radially outward from the inner skin; and an acoustic panel, the acoustic panel including a first sheet having a first plurality of perforated walls and a first plurality of non-perforated walls, a second sheet having a second plurality of perforated walls and a second plurality of non-perforated walls, the first sheet being sandwiched together with the second sheet to form an N-shaped structure having a combined plurality of perforated walls and a combined plurality of non-perforated walls.

A reusable upper stage rocket or other atmospheric re-entry vehicle includes a nose, a base opposite the nose, and a propulsion engine toward the base. The propulsion engine includes a high pressure chamber and a nozzle configured to exhaust gas generated by the high pressure chamber. The nozzle includes an initial nozzle portion, a secondary nozzle portion downstream of the initial nozzle portion, and a nozzle exit at a downstream end of the secondary nozzle portion. The secondary nozzle portion includes an inner expansion surface, an outer expansion surface outboard of the inner expansion surface, and an expansion cavity defined between the inner expansion surface and the outer expansion surface.

A gas turbine engine nacelle includes a first annular portion that is stationary and adapted for partially surrounding an engine core. The first annular portion includes a fore pylon connecting portion. A rail is coupled to the fore pylon connecting portion and extending in the aft direction from the first annular portion. A second annular portion, aft of the first annular portion and coupled to the rail, is movable along an engine core centerline between a closed position and at least one open position. The second annular portion is configured to engage with the first annular portion when the second annular portion is in the closed position, thereby providing access to the engine core. A guide pin extends forward from the second annular portion. A locking mechanism is disposed within the first annular portion for engaging the guide pin when the second annular portion is in the closed position.