A multi-pulse gas generator includes a pressure vessel, first and second propellants, a barrier membrane that separates the first propellant and the second propellant, an igniter device that produces combustion gas of igniter charge, and an igniter charge combustion gas exhaust device having exhaust holes configured to exhaust the combustion gas of the igniter charge against the second propellant. The barrier membrane includes: a concavely-deformable portion; and a convexly-deformable portion. A flow rate of the combustion gas of the igniter charge exhausted against a portion of the second propellant located outside of the concavely-deformable portion is larger than that of the combustion gas of the igniter charge exhausted against a portion of the second propellant located outside of the convexly-deformable portion.

A multi-pulse gas generator includes a pressure vessel, first and second propellants, a barrier membrane that separates the first propellant and the second propellant, an igniter device that produces combustion gas of igniter charge, and an igniter charge combustion gas exhaust device having exhaust holes configured to exhaust the combustion gas of the igniter charge against the second propellant. The barrier membrane includes: a concavely-deformable portion; and a convexly-deformable portion. A flow rate of the combustion gas of the igniter charge exhausted against a portion of the second propellant located outside of the concavely-deformable portion is larger than that of the combustion gas of the igniter charge exhausted against a portion of the second propellant located outside of the convexly-deformable portion.

An emergency landing apparatus for an aircraft and a method of operating the emergency landing apparatus is provided. The emergency landing apparatus comprises: one or more rocket motors arranged to eject efflux in order to provide upwards thrust to control descent of the aircraft during emergency landing of the aircraft; and control circuitry configured to: cause the one or more rocket motors to eject efflux and provide upwards thrust to control descent of the aircraft during emergency landing of the aircraft; and cause redirection of the efflux ejected by the one or more rocket motors, during the emergency landing of the aircraft, in order to reduce the upwards thrust provided by the one or more rocket motors.

A gas turbine engine includes a lubrication system, fuel system and thermoelectric heat exchanger adapted for selective operation in response to operational states of the gas turbine engine.

A cooling mechanism includes a bottom wall (22) in contact with a combustion chamber, an upper wall (30), and a cooling passage (40) arranged between the bottom wall (22) and the upper wall (30). The cooling passage (40) includes a first passage (50) extending to a first direction, a second passage (60) extending to the first direction, and a connection section (70) connected with the first passage (50) and the second passage (60). The second passage (60) is arranged to have an offset to the first passage (50) in a second direction perpendicular to the first direction and along the bottom wall (22).

A cooling mechanism includes a bottom wall (22) in contact with a combustion chamber, an upper wall (30), and a cooling passage (40) arranged between the bottom wall (22) and the upper wall (30). The cooling passage (40) includes a first passage (50) extending to a first direction, a second passage (60) extending to the first direction, and a connection section (70) connected with the first passage (50) and the second passage (60). The second passage (60) is arranged to have an offset to the first passage (50) in a second direction perpendicular to the first direction and along the bottom wall (22).

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 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 nuclear thermal propulsion rocket engine. A source of fissionable material such as plutonium is provided utilizing a carrier fluid having neutron moderating constituents, such as hydrogen and/or carbon, therein. A carrier fluid may be methane, or ethane, or a combination thereof. A neutron source is provided, such as from a neutron beam generator. Reactor design geometry provides containment of fissionable material in the reactor during acceleration. Collisions occur between neutrons and fissionable material injected by way of the carrier fluid. Impact of neutrons on fissionable material results in a nuclear fission in sub-critical mass reaction conditions in the reactor, resulting in release of heat energy to fluids provided to the reactor. The reactor is sized and shaped to receive the reactants and expandable fluids such as hydrogen, and to confine heated and pressurized gases for discharge out through a throat, into a rocket engine expansion nozzle for propulsive discharge, The design provides a rocket engine with a specific impulse in the range of from about eight hundred (800) seconds to about twenty five hundred (2500) seconds.

A nuclear thermal propulsion rocket engine. A source of fissionable material such as plutonium is provided utilizing a carrier fluid having neutron moderating constituents, such as hydrogen and/or carbon, therein. A carrier fluid may be methane, or ethane, or a combination thereof. A neutron source is provided, such as from a neutron beam generator. Reactor design geometry provides containment of fissionable material in the reactor during acceleration. Collisions occur between neutrons and fissionable material injected by way of the carrier fluid. Impact of neutrons on fissionable material results in a nuclear fission in sub-critical mass reaction conditions in the reactor, resulting in release of heat energy to fluids provided to the reactor. The reactor is sized and shaped to receive the reactants and expandable fluids such as hydrogen, and to confine heated and pressurized gases for discharge out through a throat, into a rocket engine expansion nozzle for propulsive discharge, The design provides a rocket engine with a specific impulse in the range of from about eight hundred (800) seconds to about twenty five hundred (2500) seconds.