Disclosed herein are various technologies pertinent to rocket engines, including injector, thrust chamber, and electrical turbopump devices that may be combined to provide a more efficient rocket engine. The electrical turbopump impeller includes a coolant bypass port fluidically connected with a coolant passage that passes through the impeller central hub and allows some of the propellant that is acted on by the impeller to bypass the impeller outlet and instead be flowed into the electrical turbopump housing so that the diverted propellant may be used to cool the various components housed within the housing such as the electric motor bearings, stator, rotor, and electronics.

Disclosed herein are various technologies pertinent to rocket engines, including injector, thrust chamber, and electrical turbopump devices that may be combined to provide a more efficient rocket engine. The electrical turbopump impeller includes a coolant bypass port fluidically connected with a coolant passage that passes through the impeller central hub and allows some of the propellant that is acted on by the impeller to bypass the impeller outlet and instead be flowed into the electrical turbopump housing so that the diverted propellant may be used to cool the various components housed within the housing such as the electric motor bearings, stator, rotor, and electronics.

Additive manufacturing includes successively forming a plurality of layers on a support. Depositing a layer from the plurality of layers includes dispensing first particles, selectively dispensing second particles in selected regions corresponding to a surface of the object, and fusing at least a portion of the layer. The layer has the first particles throughout and the second particles in the selected regions. Alternatively or in addition, forming the plurality of layers includes depositing multiple groups of layers. Depositing a group of layers includes, for each layer in the group of layers dispensing a feed material to provide the layer, and after dispensing the feed material and before dispensing a subsequent layer fusing a selected portion of the layer. After all layers in the group of layers are dispensed, a volume of the group of layers that extends through all the layers in the group of layers is fused.

Additive manufacturing includes successively forming a plurality of layers on a support. Depositing a layer from the plurality of layers includes dispensing first particles, selectively dispensing second particles in selected regions corresponding to a surface of the object, and fusing at least a portion of the layer. The layer has the first particles throughout and the second particles in the selected regions. Alternatively or in addition, forming the plurality of layers includes depositing multiple groups of layers. Depositing a group of layers includes, for each layer in the group of layers dispensing a feed material to provide the layer, and after dispensing the feed material and before dispensing a subsequent layer fusing a selected portion of the layer. After all layers in the group of layers are dispensed, a volume of the group of layers that extends through all the layers in the group of layers is fused.

In various embodiments, metallic alloy powders are formed at least in part by spray drying to form agglomerate particles and/or plasma densification to form composite particles.

An additive manufacturing system including a build plate and at least two powder reservoirs. The at least two powder reservoirs including a first powder reservoir configured to store a first powder and deposit the first powder onto the build plate, wherein the first powder reservoir is configured to move relative to the build plate, and a second powder reservoir configured to store a second powder and deposit the second powder onto the build plate, wherein the second powder reservoir is configured to move relative to the build plate. The first powder has at least one predetermined characteristic that is different than that of the second powder.

An additive manufacturing system including a build plate and at least two powder reservoirs. The at least two powder reservoirs including a first powder reservoir configured to store a first powder and deposit the first powder onto the build plate, wherein the first powder reservoir is configured to move relative to the build plate, and a second powder reservoir configured to store a second powder and deposit the second powder onto the build plate, wherein the second powder reservoir is configured to move relative to the build plate. The first powder has at least one predetermined characteristic that is different than that of the second powder.

An additive manufacturing apparatus includes a dispensing system positionable over a platen to deliver a powder, an actuator to move the dispensing system along a scan axis, and an energy source to fuse a portion of the powder. The dispensing system has a hopper to hold the powder and a dispenser. The dispenser includes a channel extending along a longitudinal axis from a proximal end to a distal end. The proximal end of the channel of the dispenser is configured to receive the powder from the powder source. A powder conveyor is positioned within the channel to move the powder from the proximal end along a length of the channel, and a plurality of apertures are arranged along the longitudinal axis of the channel. The dispenser is configured such that flow of powder through each aperture is independently controllable.

An additive manufacturing apparatus includes a dispensing system positionable over a platen to deliver a powder, an actuator to move the dispensing system along a scan axis, and an energy source to fuse a portion of the powder. The dispensing system has a hopper to hold the powder and a dispenser. The dispenser includes a channel extending along a longitudinal axis from a proximal end to a distal end. The proximal end of the channel of the dispenser is configured to receive the powder from the powder source. A powder conveyor is positioned within the channel to move the powder from the proximal end along a length of the channel, and a plurality of apertures are arranged along the longitudinal axis of the channel. The dispenser is configured such that flow of powder through each aperture is independently controllable.

Additive manufacturing includes successively forming a plurality of layers on a support. Depositing a layer from the plurality of layers includes dispensing first particles, selectively dispensing second particles in selected regions corresponding to a surface of the object, and fusing at least a portion of the layer. The layer has the first particles throughout and the second particles in the selected regions. Alternatively or in addition, forming the plurality of layers includes depositing multiple groups of layers. Depositing a group of layers includes, for each layer in the group of layers dispensing a feed material to provide the layer, and after dispensing the feed material and before dispensing a subsequent layer fusing a selected portion of the layer. After all layers in the group of layers are dispensed, a volume of the group of layers that extends through all the layers in the group of layers is fused.