The International Space Elevator Consortium has conducted a year-long study addressing the issues associated with how to start the development of space elevators. This report is the result. The process for developing an architecture for a new system of systems has many steps. Each step leads to a technological roadmap leading to a mature engineering structure. Five segment roadmaps are developed: Tether Climber, Tether, Marine Node, Apex Anchor and Headquarters Primary Operations Center. The initial set of challenges for each segment is established. These will fuel a series of demonstrations...