The device comprises two heat exchangers (74, 90) suitable respectively for vaporizing first and second propellants before they are reintroduced in gaseous form into their tanks (16, 18). The heat exchangers co-operate respectively with first and second gas generators (60, 84) suitable for being fed with a mixture of propellants in order to produce combustion, the second gas generator (84) being suitable for being fed at least in part by the exhaust from the first gas generator (60).

The device comprises two heat exchangers (74, 90) suitable respectively for vaporizing first and second propellants before they are reintroduced in gaseous form into their tanks (16, 18). The heat exchangers co-operate respectively with first and second gas generators (60, 84) suitable for being fed with a mixture of propellants in order to produce combustion, the second gas generator (84) being suitable for being fed at least in part by the exhaust from the first gas generator (60).

Devices, methods, and systems for providing a restartable ignition system for a hybrid rocket system. In one embodiment, an ignition device includes a housing and at least two electrodes. The housing includes a first side and a second side and defines a bore with an axis extending therethrough between the first and second sides, the bore defining an internal surface of the housing. The at least two electrodes extend through the housing to the internal surface. The at least two electrodes are configured to be spaced apart so as to provide an electrical potential field along the internal surface between the at least two electrodes. Such housing is formed with and includes multiple flat layers such that the multiple flat layers provide ridges along the internal surface. With this arrangement, the internal surface with the ridges are configured to concentrate an electrical charge upon being subjected to the electrical potential field.

Devices, methods, and systems for providing a restartable ignition system for a hybrid rocket system. In one embodiment, an ignition device includes a housing and at least two electrodes. The housing includes a first side and a second side and defines a bore with an axis extending therethrough between the first and second sides, the bore defining an internal surface of the housing. The at least two electrodes extend through the housing to the internal surface. The at least two electrodes are configured to be spaced apart so as to provide an electrical potential field along the internal surface between the at least two electrodes. Such housing is formed with and includes multiple flat layers such that the multiple flat layers provide ridges along the internal surface. With this arrangement, the internal surface with the ridges are configured to concentrate an electrical charge upon being subjected to the electrical potential field.

Systems and methods for a fully reusable upper stage for a multi-stage launch vehicle are provided. The reusable upper stage uses an aerospike engine for main propulsion and for vertical landing. A heat shield can include a plurality of scarfed nozzles embedded radially around a semi-spherical surface of the heat shield, wherein inboard surfaces of the plurality of scarfed nozzles collectively define an aerospike contour. The heat shield can be actively cooled to dissipate heat encountered during reentry of the upper stage.

An energetic ignition arrangement may comprise a pressure vessel arrangement, comprising a pressure vessel, and an ignition system arrangement. The ignition system arrangement may comprise an ignitor housing coupled to the pressure vessel and defining a sealing aperture, a seal disposed in the sealing aperture, and an electric match extending through the ignitor housing, wherein at least the ignitor housing and the pressure vessel are reusable after the energetic ignition arrangement has been employed in an ignition event.

An energetic ignition arrangement may comprise a pressure vessel arrangement, comprising a pressure vessel, and an ignition system arrangement. The ignition system arrangement may comprise an ignitor housing coupled to the pressure vessel and defining a sealing aperture, a seal disposed in the sealing aperture, and an electric match extending through the ignitor housing, wherein at least the ignitor housing and the pressure vessel are reusable after the energetic ignition arrangement has been employed in an ignition event.

A spark plug having an insulating body defining a longitudinal axis and including a base portion and an obstruction portion, a first electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the first electrode extending through the base portion of the insulating body, and a second electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the second electrode extending through the base portion and the obstruction portion of the insulating body, wherein the obstruction portion axially extends beyond the distal portion of the first electrode.

A spark plug having an insulating body defining a longitudinal axis and including a base portion and an obstruction portion, a first electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the first electrode extending through the base portion of the insulating body, and a second electrode including a proximal portion, a sheathed portion and a distal portion, the sheathed portion of the second electrode extending through the base portion and the obstruction portion of the insulating body, wherein the obstruction portion axially extends beyond the distal portion of the first electrode.

A method of regulating pressure within a first propellant tank of a rocket engine having a first propellant tank containing a first propellant and a second propellant tank containing a second propellant, and a regulator device for regulating pressure within the first tank, the regulator device comprising a gas generator and a heat exchanger co-operating with the gas generator so as to vaporize at least part of the first propellant prior to reintroducing it into the first tank (16), the gas generator and the heat exchanger both being fed with the first propellant by a single first motor-driven pump, while the gas generator is fed with the second propellant by a single second motor-driven pump, wherein the flow rate of the first motor-driven pump is controlled as a function of a first parameter, while the flow rate of the second motor-driven pump is controlled as a function of a second parameter.