This book explores the United States reliance on space operations for its security. Identifying vulnerabilities will allow us to apply our full range of capabilities to ensure space superiority and continued support to joint military operations across the spectrum of conflict. Space superiority is as much about protecting our space assets as it is about preparing to counter an enemy's space or anti-space assets. Space-based technologies and services permit people to communicate, companies to do business, civic groups to serve the public and scientists to conduct research. Thus, the United States is very reliant on satellites and will likely continue to be for many years to come. Today, small nations, groups, and individuals can acquire ground target data from commercial imagery sources, navigation and weather data from government-owned satellites and state of the art command and control capabilities through commercial communications satellites. These functions are also discussed in this book.