Colloid thruster

In a colloid thruster, charged liquid droplets are produced by an electrospray process and then accelerated by a static electric field.

It provides very fine attitude control or efficient acceleration of small spacecraft over long periods of time.

Eight electrospray thrusters were first used in space on the NASA ST-7 ESA LISA Pathfinder mission, to demonstrate disturbance reduction.

[3] By the end of April 2015, Busek had developed a smaller electrospray colloid thruster capable of generating 20 mN in a 17.8 x 17.8 x 4.3 cm (7"×7"×1.7") package.

This led to the discovery that the TEM environment formed needle-like structures on the thruster disrupting the way the electrospray system works.