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Christophe Béesau - Senior Expert on Solar Impulse for Advanced Modelisation and Simulation

Christophe Béesau - Altran expert on Solar Impulse for Advanced Modelisation and Simulation

Christophe Béesau

Mathematician by education, I joined Altran in 1991 with the desire to develop innovative solutions to complex problems. This complexity issue fascinates me; I think that unlike any physical standpoint, a mathematical point of view is always objective and accordingly, enables to truly manage complexity. On this premise, I developed a mathematical theory of complexity which currently serves as a basis for the “Advanced Modelisation & Simulation” department activities that I now lead.

In 2003, Altran asked me to meet André Borschberg. He presented me the Solar Impulse project, still in its infancy, and I figured out which support Altran could provide. André submitted me the concept and few major unresolved issues. At this time, there was no comparable prototype, and a lot of the forecast technologies weren’t used in aeronautics. In a classical engineer approach, taking under account all these technologies and thousands of parameters, becomes even more problematical and represents a superhuman task in terms of complexity and calculation. We then convinced André that using a totally different approach, based on a mathematical analysis of complexity, we could optimise the thousands parameters and produce an accurate modelling of the plane within a short period. Eighteen months later, instead of the 5 years predicted by experts, Solar Impulse received the first results of our calculation, gradually leading to the final design of the plane.

After developing the model of the first plane, we continued to innovate on all fronts: real time meteorological data process, ultrafine spectral phenomena modelling, extremely precise predictive routing system, reduction in calculation times with a considerable improvement in the results’ accuracy, take-off decision criteria, calculation in real time during the « Mission» countdown and even more precise analyses on the second plane...

At all stages, it was necessary to work while anticipating future needs, and sometimes to find solutions to problems that had never been resolved before. For instance, a new system has just been tested: the long-term stochastic routing optimiser, allowing to realise a predictive analysis of long-distance flights and to define an accurate optimum for these flights. A mathematical solution was found to address this kind of problems, previously unsolved.

This project is fascinating, first of all because of the message it conveys. It’s amazing to see how mentalities have changed towards green energy during the past ten years. The best evidence is the multiplication of projects concerning “solar energy exploits”: boat, airship, “taxi”… traveling around the five continents… Beyond this, on a conceptual standpoint, it’s one of the rare examples of project in which innovation is necessarily pervasive, because since the beginning, we know that figures are a priori against us. For instance, energy balance has to be so efficient that in 2003, this plane seemed unfeasible. When the USA launched the Apollo programme in 1961, they found themselves in the same position: an extraordinary idea, send a man on the Moon, and figures showing that the project was apparently unfeasible.

Today, just like the feats of the Apollo programme made an impact during the twentieth century, I think that the Solar Impulse Round the World Tour, planned for 2015, has a role to play and will represent a critical milestones for the twenty-first century.