In January 2017 TGO’s orbit was adjusted to an inclination of 74°, which is optimised for its science and radio relay missions, and it will moved from a 4-day to a 1-day orbit.
During 2017 it used sophisticated aerobraking techniques – the first time ESA has done so to attain a science orbit around another body in our Solar System – to steadily lower itself to a circular, 400 km orbit.
With aerobraking, the TGO solar array will experience tiny amounts of drag owing to the wisps of martian atmosphere at very high altitudes, which will slow the craft and lower its orbit. While aerobraking takes time, it uses very little fuel and will itself provide scientific insight into the dynamics of Mars’ atmosphere.