Use of a pathfinder optical telescope element for James Webb Space Telescope risk mitigation

A Pathfinder of the James Webb Space Telescope (JWST) Optical Telescope Element is being developed to check out critical ground support equipment and to rehearse integration and testing procedures. This paper provides a summary of the baseline Pathfinder configuration and architecture, objectives of this effort, limitations of Pathfinder, status of its development, and future plans. Special attention is paid to risks that will be mitigated by Pathfinder.