Effects of hostile space weather on satellite operations

We present a review of recent evidence for space environmental impacts on satellite operations. We note the effects of cosmic and solar energetic particle radiation as well as the effects of high-energy magnetospheric particles. Statistical as well as case-specific examples of severe oper-ational anomalies are examined. In addition to the obvious impacts of the most extreme space weather episodes, we note that there are important space environmental effects that are more subtle. These have been manifested in the recent (2007-2010) period of remarkable solar quiescence. We conclude with a description of possible space weather in the approaching solar activity maximum period.