Controller and Communications Middleware Survey and Evaluation.

There is a need for a standard core architecture to reduce the costs of developing and maintaining ground control systems for different satellites. This report documents a survey and evaluation of next generation computing technology trends relevant to the need. In addition to the advent of the Internet, there are two Important on-going evolutions impacting the area - the migration to distributed client-server computing and the paradigm shift to object-oriented OO programming. New application software is being developed based on a distributed object model and clients are tied to servers by software called middleware. Available commercial-off-the- shelf COTS controller and communication middleware are evaluated for their applicability to satellite ground stations and for distributed processing, distributed database access, and distributed systems management. Available products and vendors are listed. Low-cost satellite ground station application software with the flexibility to adapt as requirements change can be built using COTS-available middleware. Although most middleware frees the application developer from the need for network programming, it nevertheless requires an experienced implementation staff for the selection of an integrated set of middleware products.