Space sustainability has become a buzzword for the space industry. But what does the term mean? Dr Timiebi Aganaba, Assistant Professor of Space and Society at Arizona State University, outlines the ecological roots of the term and why today's discussions often revolve around global security. We talk about ‘the space club’ (were we not supposed to?), transparency in the behaviour of countries and space agencies and what they launch into space, and why Africa will be a game-changer for space exploration.