Firstly, electric propulsion engines
are more efficient than chemical ones for controlling spacecraft velocity as
significantly less propellant is required. This is achieved via the high
propulsion speeds of electric propulsion thrusters. Secondly, electric
thrusters operate in low flow conditions to propel the spacecraft with minimal
force. This enables fine tuning of the spacecraft’s position and orientation in
the orbit with high precision in extended periods of time (i.e., months or years).