Preliminary Doppler signal

Doppler measurements show how fast a spacecraft is moving relative to a ground station. Around 12:00, the team saw a sudden change of 7.5 cm/s in BepiColombo's signal, exactly matching predictions for MTM separation. The signature provided the preliminary indication to the Flight Dynamics team that the separation had taken place. Upon detection, flight dynamics specialists eagerly labelled the shift "SEP" for separation (not to be confused with the acronym for solar electric propulsion).