This chapter applies the knowledge from Chapter 3 to a few illustrative satellite systems. The Hubble Space Telescope is one of the most impressive illustrations of the technology, even after 25 years of service. Smaller (commercial) systems are described as well, and illustrations are given of nighttime imaging. The science and technology of remote sensing involves the propagation of light from source to subject to sensor and relies on an understanding of the platform (or satellite bus) and the processes that transmit remotely sensed imagery to the ground. The Hubble Space Telescope illustrates all of these elements in the image chain.