How will the Rover robot evolve during its expedition to Mars in 2018? To find out, the European Space Agency's ExoMars research programme and Airbus Defence and Space have entrusted Bouygues Energies & Services with the turnkey construction of the Mars Yard, a high-tech room that recreates the surface and atmosphere of the red planet, in order to run condition tests. A major challenge is to reproduce the red planet’s extremely demanding temperature, humidity and cleanliness constraints.