Cassini CAPS ground system evolution and lessons learned

Recently the Cassini CAPS team investigated the number of different software tools, programming languages, programs, and major technologies used in building and running its ground system. A total of twenty six different tools, programs, and major technologies were used in the downlink portion of the ground system and five different tools, programs, and major technologies are used for the uplink portion. This collection of tools, programs, and technologies were not considered in the initial ground system design at the beginning of operations, but were added as they were needed to address changing requirements. During the pre-launch phase of Cassini Huygens in 1997, operations were performed in a limited capacity in the calibration facilities. After launch, process automation increased gradually, as the ground system continued to grow. New technologies were incorporated as they emerged, and were added to the ground system, although they may not have been part of the initial plans. This led to some unexpected and sometimes creative inter-connectivity solutions to ensure that they could be integrated with the existing system. This paper will document the changes in the ground system from the period just before the first instrument check-out in January 1999 through the end of 2008. We will discuss why the technologies, programs, and tools were added. Lastly, we will look at the ground system from a management perspective in an attempt to determine how the system could have been built modularly, considering that emerging technologies and other capabilities could be added at a later date.