The paths of the ExoMars 2016 Trace Gas Orbiter (TGO) and the Schiaparelli entry, descent and landing demonstrator module arriving at Mars on 19 October (right and left, respectively). The counter begins at the start of a critical engine burn that TGO must conduct in order to enter Mars orbit. The altitude above Mars is also indicated, showing the arrival of Schiaparelli on the surface and the subsequent trajectory of TGO. The orbiter's initial 4-day orbit will be about 250 x 100 000 km. Starting in December 2016, the spacecraft will perform a series of aerobraking manoeuvres to steadily lower it into a circular, 400 km orbit (not shown here).