European rover trains for Mars in the desert

For eight days in September, a Mars rover prototype named Charlie travelled 220 metres across a barren landscape in the Tabernas desert of south-eastern Spain, following commands from a science team about 1,200 kilometres away. The exercise brought together around 100 scientists and engineers from across Europe and served as an important rehearsal for what the ExoMars Rosalind Franklin rover might encounter when it lands on Mars in 2030. Tabernas was chosen partly for its resemblance to a Mars landscape; planetary scientist Elliot Sefton-Nash said the site's local geology and mineralogy allowed a scenario realistic enough to stress-test science operations processes for interpretations and decision-making, even though the area is famous for Indiana Jones and spaghetti western movies.

Charlie, built by Airbus, ran the same guidance, navigation and control software that will allow Rosalind Franklin to reach a target while avoiding hazards. At the Rover Operations Control Centre (ROCC) in Turin, Italy, the science team relied on rover images, subsurface radar and spectral analysis to identify the most promising locations to search for evidence of life—Rosalind Franklin's main mission objective. Together, the teams choreographed how the robotic explorer could move safely, exercise exploration strategies and maximise scientific results.

Operations lead Luc Joudrier said the rover 'worked like a charm', including being left to explore on its own: on day six it travelled more than 60 metres without any operator at the wheel, with less than a 1% navigation error. Success depended on teamwork and coordination between control-centre teams and field operators, with constant planning and scientific interpretation happening in parallel; Joudrier said the immersion was so strong that at times they felt they were on Mars.

The simulation posed a realistic mission scenario that challenged the remote teams. On one occasion, the steepness of a slope was difficult to gauge from the data sent by the rover, prompting Chiara Lombardi, ExoMars rover and lander system engineer, to say: 'Where we thought there was an elephant, the operators in the desert just saw a mouse.' The team initially took a conservative, safe-side approach, then used a digital elevation map to confirm it was a gentle incline. On another day, rain interrupted the desert tests, and the team learned to re-plan and reassign priorities when faced with the unexpected.

While the rover sent self-location parameters, measurements and images from the field, planners and scientists at ROCC worked around the clock in response, underscoring the remote, data-driven nature of the operations being rehearsed.