Image: Made for Mercury

On 6 March 2018, the BepiColombo engineering model was delivered to ESA's mission control centre in Darmstadt, Germany.

BepiColombo – ESA's first mission to Mercury – is based on two spacecraft: the ESA-led Mercury Planetary Orbiter, with 11 experiments and instruments, and the Japanese space agency-led Mercury Magnetospheric Orbiter, carrying five experiments and instruments.

The engineering model delivered to Darmstadt comprises a 3-D mock-up of the ESA module, plus a 'flat-sat' mock-up of the transfer module, which ties the ESA and Japanese modules together during their cruise to Mercury.

In this photo, Airbus technician Stanislaw Ballardt looks out from inside the ESA module during installation work on 7 March.

The engineering model is an electrically faithful replication of the most critical elements of the spacecraft's main platform and flight control systems, such as its computers, mass memory and power systems.

Flight controllers will use the model throughout the mission to check software and procedures before uploading them to the real spacecraft. They will also train for flight events such as firing the electric thrusters, swinging by planets and separating the modules.