ESA Science & Technology - Interplanetary cruise phase for the BepiColombo mission

Artist's impression of the Mercury Composite Spacecraft during the interplanetary cruise to Mercury. During this phase of the mission, the solar electric propulsion system will be used to brake against the Sun's increasingly stronger pull as the spacecraft travels toward the Solar System's innermost planet.

Two sets of two ion engines (one set for redundancy) are situated at the end of the Mercury Transfer Module, in a square configuration around the nozzle of the main chemical engine.