The space environment is highly dynamic and has its own weather, similar to terrestrial weather. With our permanent manned presence in space and as our utilization of and reliance on space increases, specification and prediction of space weather becomes increasingly important. Real-time measurement from operational spacecraft, such as the NOAA GOES and POES, as well as new numerical models are allowing exciting advances in our ability to predict space weather. In this presentation, we will overview the needs and capabilities of space weather prediction today, and compare the capabilities and challenges of space and terrestrial weather prediction.