Fifty-five years ago, the space age dawned with the launch of Sputnik 1, the world's first satellite. It fell from orbit after 3 months and burned up upon re-entering Earth's atmosphere. But, for most space craft, this is not the case. The proliferation of debris orbiting the Earth, primarily jettisoned rocket and satellite components, is a pressing problem for spacecraft and satellites. There are significant costs in avoiding collisions with space junk. Derek Muller visits the Swiss Space Centre to meet the scientists building the first satellite specially designed to clean up space debris.