Students learn how engineers navigate satellites in orbit around the Earth and on their way to other planets in the solar system. In accompanying activities, they explore how ground-based tracking and onboard measurements are performed. Also provided is an overview of orbits and spacecraft trajectories from Earth to other planets, and how spacecraft are tracked from the ground using the Deep Space Network (DSN). DSN measurements are the primary means for navigating unmanned vehicles in space. Onboard spacecraft instruments might include optical sensors and an inertial measurement unit (IMU).