How TGO will orbit Mars
While Schiaparelli is landing on Mars, TGO will conduct a critical engine burn with its main engine – the Mars Orbit Insertion manoeuvre. This will slow TGO sufficiently to be captured into an initial orbit, and will last for over two hours. Upon completion, it will mark the second time that ESA has placed a spacecraft into orbit around the Red Planet.
The initial highly eccentric orbit is dubbed the ‘4 Sol’ orbit, as it will take TGO four martian days to complete one revolution, with its altitude above Mars varying between a few hundred kilometres at its closest point and nearly 100 000 km at its furthest.
In January 2017 TGO’s orbit will be adjusted to an inclination of 74°, which is optimised for its science and radio relay missions, and it will move from a 4-day to a 1-day orbit.
During 2017 it will employ sophisticated aerobraking techniques – the first time ESA will do 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.
Last update: 3 March 2016