Nanosat fleet proposed for voyage to 300 asteroids

A fleet of 50 tiny spacecraft could visit over 300 asteroids in around three years, according to a mission concept proposed by Europe-based researchers. The 5-kg satellites, tethered to a main spacecraft, would be propelled by solar wind. They would flyby their target asteroids at a range of around 1,000 kilometres, imaging their surface with a resolution of 100 metres.