Development of JWST's Ground Systems Using an Open Adaptable Architecture

摘要

After four years of real-life experiences with an open architecture, the JWST ground system team has noted the following lessons learned: 1) Central XML database that is application independent was instrumental in minimizing the cost and impact as the database matures. The JWST database XML implementation also allowed for JWST to be compliant with the CCSDS XTCE without much effort. 2) Various vendors supplying different components works well for keeping the total system open and adaptable, but increases the amount of coordination between the various delivery schedules. 3) Separating real-time functions from engineering functions is a major step for ground systems. 4) Interoperable lug and play concept works as long as the ICDs are defined for the interfaces. Also the middleware software for exchanging information between systems needs to be thought about at the beginning of system development, even though implementation may be years away. 5) Open engineering and science data formats that are defined in an 1CD allow for dissimilar systems to have access to the data without impacting the design. 6) CCSDS CFDP reduces the amount of processing needed at the end user site, increases the data efficiency, and eases the problems of onboard recorder management. This CCSDS protocol is a win-win for all users. 7) Use of web-based technologies for the end user displays provides more flexibility, quicker development, and reduces long-term cost.