Abstract: 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.