The magic of ion engines


Artist's impression of SMART-1 ion engine
 
How an ion engine works. Electrons attracted into the discharge chamber collide with xenon atoms from the propellant gas supply, making charged atoms (ions). Current-carrying coils, inside and outside the doughnut-shaped discharge chamber, sustain a magnetic field oriented like the spokes of a wheel. By the Hall effect, ions and electrons swerving in opposite directions in the magnetic field create an electric field. This expels the xenon ions in a propulsive jet. Other emitted electrons then neutralise the xenon, producing the blue jet.

SMART-1 is the first of ESA’s Small Missions for Advanced Research in Technology. It will head for the Moon using solar-electric propulsion and carrying a battery of miniaturised instruments.

ESA's Artemis
 
ESA's Artemis - saved from the grave by its ion engines. After its launch in 2001, put this experimental telecommunications satellite into too low an orbit, ion engines intended only for manoeuvring have gradually raised the orbit.

BepiColombo
 
BepiColombo;
BepiColombo and Solar Orbiter are ESA's first long-range science missions designated to use an ion engine

Solar Orbiter
 
Solar Orbiter;
BepiColombo and Solar Orbiter are ESA's first long-range science missions designated to use an ion engine

The SMART-1 ion engine being test fired
 
The SMART-1 ion engine being test fired



Last update: 31 August 2006