This course provides a detailed overview of artificial objects orbiting the Earth, namely satellites, and the problematic consequence of satellite launches, space debris. Topics covered include the history and present status of the common orbital regimes around the Earth, what satellites are up there and how we use them, particularly the Global Navigation Satellite Systems. We will also review the techniques used for tracking the ever-increasing number of objects being launched. The course will introduce orbital mechanics and cover some of the complications associated with predicting the future locations of the thousands and thousands of satellites and space debris in orbit.