BepiColombo’s cruise configuration

This artist’s view shows the two BepiColombo orbiters (MPO and MMO) mounted on top of their transfer module (cruise configuration).

For its journey to Mercury BepiColombo will cleverly use the gravity of the Moon, Earth, Venus and Mercury itself in combination with the thrust provided by solar-electric propulsion (SEP). During the voyage to Mercury, the two orbiters and transfer module, consisting of solar-electric propulsion and chemical propulsion units, will form one single composite spacecraft.

On approach to Mercury, the transfer module will separate and the composite spacecraft use conventional rocket engines and the so-called 'weak stability boundary capture technique' to bring it into polar orbit around the planet. When the MMO orbit is reached, the MPO will separate and lower its altitude to its operational orbit by chemical propulsion. Scientific investigations will go on for at least one Earth year (four Mercury orbits around the Sun).