From the first artificial satellite, Sputnik, to the cutting-edge technology of today's Mars rovers, this volume explores the history of unmanned space exploration. Readers discover how these fascinating machines orbit our planet and beyond, collecting invaluable data and imagery that help us better understand our place in the cosmos. Detailed graphic organizers and a glossary of new terms give young adults an in-depth understanding of the science behind these high-tech machines, and vivid full-color photographs show them space as seen through the eyes of satellites such as the James Webb Telescope.