etailed understanding of the energetic charged particle environment and the effects which are produced as these particles interact with sensitive devices is essential to the development of satellite systems. Design for compatibility with the space environment requires a complete spectrum of mitigation techniques in the development of cost effective systems, including component level solutions as well as fault tolerance techniques implemented at the system and subsystem applications level. The selection of technology and fault tolerance strategy to be utilized in system development must be supportive of high availability, and provide power efficient implementations. Although availability and reliability connote similar attributes, availability to subscribers is the revenue producing result; reliability is one of the elements which support availability and cost effectiveness. Efficient utilization of satellite power is an important attribute of telecommunications payloads; optimum allocation of power to subscriber RF link operation is necessary. Inefficient technology, or an implementation which results in higher than necessary operating power, requires additional solar array area to produce power, larger batteries to store the power, and a more robust thermal management system to transfer the heat. All of these needs translate to increased payload weight, and hence degrade the cost effectiveness of the system. A fault tolerant system design embodies the principles of fault avoidance, fault masking, detection of compromised system operation, containment of error propagation, and recovery to normal system operations. Consideration of some of the techniques in each of these subject areas is applicable to the design and development of telecommunications satellite systems. Space Telecommunications Industry Historical Perspective [SIA98] [Whalen98] From the inception of man-made satellite development and deployment, telecommunication has been the objective of the majority of space systems. Today, satellite based telecom