Electrical ignition of electrically operated propellant in a gas generation system provides an ignition condition at an ignition surface between a pair of electrodes that satisfies three criteria of a current density J that exhibits a decreasing gradient along an axis normal to an ignition surface, is substantially constant across the ignition surface and exceeds an ignition threshold at the ignition surface. These criteria may be satisfied by one or more of an angled electrode configuration, a segmented electrode configuration or an additive to the electrically operated propellant that modifies its conductivity. These configurations improve burn rate control and consumption of the available propellant and are scalable to greater propellant mass to support larger gas generation systems.

Electrical ignition of electrically operated propellant in a gas generation system provides an ignition condition at an ignition surface between a pair of electrodes that satisfies three criteria of a current density J that exhibits a decreasing gradient along an axis normal to an ignition surface, is substantially constant across the ignition surface and exceeds an ignition threshold at the ignition surface. These criteria may be satisfied by one or more of an angled electrode configuration, a segmented electrode configuration or an additive to the electrically operated propellant that modifies its conductivity. These configurations improve burn rate control and consumption of the available propellant and are scalable to greater propellant mass to support larger gas generation systems.

A turbojet engine capable of operation in an Air Turbo Rocket (ATR) mode includes a compressor, a rotatable turbine wheel comprising turbine blades, a non-rotating guide vane ring comprising guide vanes, a turbine shaft configured to power said compressor, a combustor, a gas generator, and a main combustor. The main combustor is configured to combust hot, fuel rich gas from the gas generator in air compressed by the compressor. Hot, fuel rich gas from the gas generator is directed towards the turbine blades by a directing means.

A power generation system includes a manifold having multiple plenums, capable of receiving multiple solid rocket motors. Initiators are coupled to the manifold, and are operatively coupled to respective of the plenums, to selectively fire different groups of the rocket motors coupled to respective of the plenums. The rocket motors act in parallel, to provide thrust in a single direction. The initiators may activate ignition charges that are in the plenums. The plenums may be annular plenums, which may be located in an annular manifold. The plenums may be lined with an insulator material. A cover may be used to cover the plenums, and also to receive the rocket motors. The rocket motors may be solid-fuel rocket motors, with propellant grains and nozzles. The individual rocket motors may have separate ignition booster charges coupled to the plenum, which are ignited by the ignition charge.

A power generation system includes a manifold having multiple plenums, capable of receiving multiple solid rocket motors. Initiators are coupled to the manifold, and are operatively coupled to respective of the plenums, to selectively fire different groups of the rocket motors coupled to respective of the plenums. The rocket motors act in parallel, to provide thrust in a single direction. The initiators may activate ignition charges that are in the plenums. The plenums may be annular plenums, which may be located in an annular manifold. The plenums may be lined with an insulator material. A cover may be used to cover the plenums, and also to receive the rocket motors. The rocket motors may be solid-fuel rocket motors, with propellant grains and nozzles. The individual rocket motors may have separate ignition booster charges coupled to the plenum, which are ignited by the ignition charge.

A solid rocket motor is described that includes a solid propellant section, a nozzle, and a source of monopropellant, such as liquid monopropellant. The monopropellant is used to control various operational parameters of the solid rocket motor, such as thrust vector control, roll control, extinguishment of the motor, and cooling of the nozzle and/or nozzle throat. The nozzle and the nozzle throat can be an integrated, single piece assembly that facilitates re-use of the nozzle.

A solid rocket motor is described that includes a solid propellant section, a nozzle, and a source of monopropellant, such as liquid monopropellant. The monopropellant is used to control various operational parameters of the solid rocket motor, such as thrust vector control, roll control, extinguishment of the motor, and cooling of the nozzle and/or nozzle throat. The nozzle and the nozzle throat can be an integrated, single piece assembly that facilitates re-use of the nozzle.

Various implementations of an extinguishable, solid propellant divert system for a flight vehicle are disclosed. Also disclosed are methods for using the divert system to control the flight of a flight vehicle. In one implementation, a divert system includes a hot gas generator pneumatically linked to one or more divert thrusters and an extinguishment valve. The extinguishment valve can be opened to rapidly depressurize the hot gas generator and extinguish the solid propellant burning inside. In another implementation, a method of controlling the trajectory of the flight vehicle includes repeatedly igniting and extinguishing the solid propellant in a hot gas generator and using the hot gas to provide divert thrust for the flight vehicle.

Various implementations of an extinguishable, solid propellant divert system for a flight vehicle are disclosed. Also disclosed are methods for using the divert system to control the flight of a flight vehicle. In one implementation, a divert system includes a hot gas generator pneumatically linked to one or more divert thrusters and an extinguishment valve. The extinguishment valve can be opened to rapidly depressurize the hot gas generator and extinguish the solid propellant burning inside. In another implementation, a method of controlling the trajectory of the flight vehicle includes repeatedly igniting and extinguishing the solid propellant in a hot gas generator and using the hot gas to provide divert thrust for the flight vehicle.

A thruster includes multiple segments of electrically-operated propellant, electrodes for igniting one or a few of the electrically-operated propellant segments at a time, and a propellant feeder for moving further propellant segments into engagement with the electrodes. The segments may be configured to provide equal increments of thrust, or different amounts of thrust. The segments may each include an electrically-operated propellant material surrounded by a sealing material, so as to keep the propellant material away from moisture and other contaminants (and/or the vacuum of space) before each individual segment is to be used. The thruster may be included in any of a variety of flight vehicles, for example in a small satellite such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.