What is an Electrospray Thruster?
An Electrospray Thruster is a type of Ion Thruster that produces low thrust by using a strong electric field to accelerate charged liquid droplets. Some types of electrospray thrusters use a mixture or a combination of different liquids as propellant and hence are known as colloids. Therefore these thrusters are also known as Colloid thrusters.
Electrospray thruster works when an external positive or negative potential is applied between the conductive liquid propellant (often an ionic liquid) and an extraction electrode which is aligned with the emitter which in turn produces a spray of liquid particles. An accelerator electrode is used which provides an additional potential to increase the thrust capacity. Electrospray thruster is highly efficient like ion thrusters and has high thrust density as well as high specific impulse.
Electrospray thrusters are also characterized by the propellant used and the emission mode of the ion beam. The most common is field emission electric propulsion (FEEP), which utilizes liquid metals as its ion source to produce positively charged ions and/or droplets.
