Abstract:
A system is used for additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.
Abstract:
A method of making an electrical connection includes soldering using channels in a receptacle to direct hot air (or another hot gas) to effect soldering where the electrical connection is to be made. The connection may be made between device electrical contacts of an electrical device, and other contacts, such as receptacle contacts of the receptacle. The connection may be a blind connection, one in which the connected ends of the contacts are hidden or unable to be directly physically accessed, when the connection is made. The electrical connection may be made between device contacts of an electrical device that is inserted into the receptacle, and receptacle electrical contacts that are part of the receptacle. The channels for directing the hot gas to where the soldering occurs may be parts of the receptacle, for example being produced during additive manufacture of the receptacle.
Abstract:
A thruster has an additively-manufactured housing that includes an integrally-formed nozzle with a burst disk in it. The housing is part of a casing that surrounds and encloses a propellant that is burned to produce pressurized gases that burst the burst disk and produce thrust. The thruster may be placed in a receptacle that defines a recess for receiving the thruster. The receptacle also may be additively manufactured. The thruster and the recess both may be cylindrical, with the housing being closely fit with the cylindrical walls of the receptacle. This may allow some of the structural loads on the housing, such as loads produced by the combustion of the propellant, to be transferred to the adjoining walls of the receptacle. This enables the housing to have less structural strength than if it were to have to contain the pressure from the propellant all on its own.
Abstract:
A projectile, such as a railgun-launched projectile, includes a single-piece body that is additively manufactured. The single piece body includes fuel within it, and one or more cavities for receiving an oxidizer. The body also defines one or more combustion chambers therein for combustion of the fuel and oxidizer as part of a divert thruster system. Thus the projectile is able to fully contain the divert thruster system within the single-piece body without using any hot gas seals as part of the system. The body may also define a cavity for receiving a pressurized fluid, used as part of a cold-gas attitude control system of the projectile. The body may also define passages between the pressurized fluid cavity and other parts of the attitude control system, such as valves and/or nozzles that are outside of the body, for example being aft of the one-piece body.
Abstract:
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.
Abstract:
A combustible element includes regions of fuel material interspersed with regions of oxidizer material. The element may be made by additive manufacturing processes, such as three-dimensional printing, with the fuel material regions and the oxidizer material regions placed in appropriate locations in layer of the combustible element. For example, different extruders may be used to extrude and deposit portions of a fuel filament and an oxidizer filament at different locations in each layer of the combustible element. The combustible element may define a combustion chamber within the element, where combustion occurs when the combustible element is ignited. The fuel material and the oxidizer material may be selected, and their relative amounts may be controlled, such that desired relative amounts of fuel and oxidizer are present for combustion with desired characteristics, such as combustion rate.
Abstract:
A combustible element includes regions of fuel material interspersed with regions of oxidizer material. The element may be made by additive manufacturing processes, such as three-dimensional printing, with the fuel material regions and the oxidizer material regions placed in appropriate locations in layer of the combustible element. For example, different extruders may be used to extrude and deposit portions of a fuel filament and an oxidizer filament at different locations in each layer of the combustible element. The combustible element may define a combustion chamber within the element, where combustion occurs when the combustible element is ignited. The fuel material and the oxidizer material may be selected, and their relative amounts may be controlled, such that desired relative amounts of fuel and oxidizer are present for combustion with desired characteristics, such as combustion rate.
Abstract:
A spacecraft, such as a satellite, uses a shape memory polymer actuator to deploy one or more deployable parts. The shape memory polymer actuator may be formed integrally with a deployable part and/or with a fuselage or other structure of the spacecraft, with the shape memory polymer actuator being for example a relatively thin portion of the shape memory polymer material of the integral structure. The shape memory actuator allows deployment of the deployable part(s) upon heating of the shape memory polymer material of the actuator, such as after the satellite has been launched into space. The heating may be caused by a heat source that is part of the spacecraft itself, or may be merely the result of exposing the spacecraft to solar heating after launch. The deployable part of the spacecraft may include any of a wide variety of parts that are used after launch.
Abstract:
A method of additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.
Abstract:
A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be 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.