Keeping Rosalind Franklin in sight

Once TGO is set to orbit with the new, optimised orientation around Mars, it must also be on the correct side of the planet when the rover arrives – ‘in phase’ with Rosalind Franklin.

The black line represents TGO’s orbit around Mars at the time Rosalind Franklin begins its descent, itself shown by the green line.

Blue dots along the orbits of TGO and Rosalind Franklin are connected by horizontal lines, illustrating the two spacecrafts’ relative positions at different time intervals, and how they are able to ‘see’ each other at every moment, thus ensuring that radio contact can be maintained.