This lecture discusses the growing issue of space debris and its impact on satellite operations. The instructor highlights the exponential increase in satellites and the 130 million objects currently orbiting Earth, which pose significant threats to operational satellites. Various institutions are cataloging these objects, but the problem remains unresolved. The lecture introduces a project by ClearSpace, an EPFL spin-off supported by ESA, aimed at developing missions to collect and safely dispose of space debris. The project consists of two main components: hardware, including a prototype telescope named Lost, and software for object detection and trajectory simulations. The telescope captures images of satellite tracks, while future enhancements will include a radio wave receiver for data collection in cloudy conditions. The project, initiated in 2020, involves a multidisciplinary team of students and aims to promote sustainability in space by managing low Earth orbit as a limited resource. The lecture emphasizes the importance of accurate data for successful debris removal operations and aligns with UN sustainability goals.