The availability and quantity of water is essential to life on earth, and helps to tie together the Earth’s lands, oceans and atmosphere into an integrated physical system. “Water is at the heart of both the causes and effects of climate change” (NRC, 1999). Many of the components of the global water cycle prediction system are available, but are not integrated. There are still gaps in our understanding, observation systems, and modeling that need to be addressed before being able to provide the public with better predictions for the protection of human health and assets, system management, and planning. NASA is capable of and uniquely positioned to investigate the global climatic processes that govern precipitation and the replenishment of water resources. Our goal is to integrate these capabilities, and to bridge the gap in water-cycle research. This would ultimately result in an end to end research strategy which would advance scientific understanding and prediction of the water cycle that could be used to quantify hydrologic predictions based on data from global observations systems. The poster presented would show the various components of water cycle research activities at NASA/Goddard Space Flight Center: what we know, and what is needed to be done and how we are attempting to integrate these areas.