Meteosat Third Generation (MTG) is the next generation of European meteorological geostationary satellites, set to be launched in 2021. Besides ensuring continuity with Meteosat Second Generation imagery mission, the new series will feature new instruments, such as the Lightning Imager (LI), a high-speed optical detector providing near real-time lightning detection capabilities over Europe and Africa. The instrument will register events on pixels, where a lightning pulse generates a transient in the acquired radiance. In parallel, signal variations due to a number of unwanted sources, e.g., acquisition noise or jitter movement, are expected to produce false events. The challenge for on-board and on-ground processing is, thus, to discard as many false events as possible while keeping a majority of the true lightning events. This paper discusses a chain of algorithms that can be used by the LI for the detection of lightning and for the filtering of false events. Some of these algorithms have been developed in the framework of internal research and simulations conducted by the MTG team at the European Space Agency on an in-house LI simulator and therefore will not necessarily reflect the ultimate operational processing chain. The application of the chain on a representative scenario shows that 99.5% of the false events can be eliminated while keeping 83.6% of the true events, before generating the LI higher level data products. Machine learning techniques have also been studied as an alternative for on-ground event processing, and preliminary results indicate promising potential.

According to the Global Exploration Roadmap, which reflects the international effort to define feasible and sustainable exploration pathways to the Moon, near-Earth asteroids and Mars, the next step for manned space exploration is the Moon as second home in the Solar System. In that perspective, the Earth-Moon Libration points (EML points) have been a topic of great interest in recent years since EML1 and EML2 were suggested as advantageous locations of space hubs in the Moon neighborhood. To materialize this vision, detailed studies are needed to investigate transfers between Earth and the vicinity of EML2 and the strategies to reduce associated maneuver costs. This work is framed within the perspective of a future deep space habitat in halo orbit around EML2, and this paper intends to provide quantitative results so as to select the best deployment scenario of the station. The main purpose is to determine the best transfer trajectory between a low-Earth orbit and a halo orbit around EML2 in terms of cost and duration. Two different kinds of attractive transfer strategies have been identified. Station deployment and cargo missions would use Weak Stability Boundary (WSB) trajectories whereas manned flights would exploit a fly-by strategy as it shows an advantageous compromise between short trip duration and efficiency.