Lessons Learned in Building a Spacecraft XML Taxonomy and Ontology

[Abstract] Plug and Play spacecraft offer the potential for simplified flight software development, rapid spacecraft assembly and integration, late addition of new components and technologies, and more automated testing and post-deployment flexibility. The Air Force Research Laboratory (AFRL) has established a program to develop standards for Space Plug and Play Avionics (SPA) that is based on commercial technologies, including USB. One of the outstanding issues in SPA is the development of a common data vocabulary that uniquely defines a finite set of spacecraft components and their structural and functional relationships. This common data vocabulary would form the core of an easy-touse tool set that would assist non-experts in defining the bus and payload for rapid-response spacecraft. The common data vocabulary would also enable true Plug and Play functionality by automatically defining component interfaces above the physical networking layer. Recently, the NASA New Millennium Program (NMP) and The Aerospace Corporation developed a spacecraft taxonomy and ontology database known as XCALIBR (XML Capability Analysis Library). This paper describes the potential application of the XCALIBR ontology and development process to the SPA common data vocabulary problem.