Nadir observations of sprites from the International Space Station

The experiment LSO (Lightning and Sprite Observations), on board of the International Space Station, is dedicated to nadir observations of sprites. It proposes a new observation method based on spectral differentiation of sprites and lightning with the use of an adapted filter. The experiment is composed of two micro-cameras, fixed on a station window. The experiments are automatic and programmed by a PC. One camera is equipped with a filter and measures the sprites in the N2 1P most intense emission line, the second provide observations in the visible. Measurements were performed in the frame of the flight of European astronauts (France, Belgium, Spain) and a cooperation program with Russia. Among 180 transitory events, 15 sprites were identified. Measurements from space are needed to determine the mechanisms at the origin of these phenomena and their impact on the Earth environment. This measurement concept will be used for the measurements from space of EM and particle emissions associated with sprites by the micro-satellite Taranis.