Light flash observation in space: Experiment ELFO

They present the scientific case for a thorough investigation of light flashes (LFs) observed by astronauts since early lunar missions. A complete assessment of the phenomenon is achieved through a sophisticated helmet-like silicon detector put on the head of the astronauts. This device will be able to identify cosmic-ray nuclei and measure their energy and trajectory, in order to correlate each light flash with the single particle likely to produce this effect. In addition, a study of precise time-correlation between cosmic-ray impinging on the head of the cosmonaut and functions in the Central Nervous System (CNS) is addressed via investigation of the concurrent spontaneous bioelectrical cortical activity in the cortex (EEG) and of retinal and cortical responses at luminance and contrast stimuli (ERG, VEP). This joint knowledge will help to identify the interaction mechanism behind light flashes, and to build better models of the visual sensory processes. The silicon detector will also give information for a more accurate biological dosimetry by the knowledge of the relative fluences of the different particles: a contribution for a deeper understanding of the physiological modifications during long manned missions. The proposed apparatus is supposed to work on-board of the Russian MIR Space Station or, later, on board of the International Space Station ALPHA