Synthesis of the planetary exploration-horizon 2061-foresight exercise

The "Planetary Exploration, Horizon 2061" long-Term community foresight exercise has been proposed by the Air and Space Academy and led by scientists, engineers and technology experts heavily involved in planetary sciences and in the exploration of the Solar System. This foresight exercise has been elaborated over 3 workshops held in 2016 in Bern, in 2018 in Lausanne and in 2019 in Toulouse. It has been opened to all scientists, engineers, technicians, journalists, industry and space agencies, students and people interested in the future of planetary exploration and the space adventure. The ultimate objective of this sequence of workshops was to develop a longterm picture of the four pillars of planetary exploration: 1.The major scientific questions; 2.The different types of relevant space missions; 3.The key required technologies; 4.The needs in terms of supporting infrastructures and services. The year 2061 corresponds to the return of Halley's comet into the inner Solar System, the centennial of the first human space flight, and President Kennedy's Moon initiative. It symbolizes the intention to encompass both robotic and human exploration in the same perspective. In the early workshops, planetary scientists were invited to formulate the most important scientific questions that need to be addressed and solved to make progress in our understanding of Planetary Systems, a new class of astrophysical objects which are ubiquitous in our Galactic neighbourhood but can be explored in-situ only in our Solar System! These science questions have been formulated independently of the a priori technical possibilities to address them. Subsequently, engineers and technology experts have been invited to contribute to the exercise to seek for innovative technical solutions that will make it possible to fly the challenging space missions needed. We will give an overview of Horizon 2061 results. The talk will give a particular focus on pillar 2, elaborating the major future planetary exploration missions that would provide the measurements needed to answer a set of 6 fundamental questions about planetary systems, and about the solar system as the only one we can explore in situ with space probes. We will also address the new technologies required to achieve those missions.