Tansei-3, also known as TRMM (Tropical Rainfall Measuring Mission), was a collaborative satellite mission between NASA and the Japan Aerospace Exploration Agency (JAXA). Tansei-3, or TRMM, was designed to study tropical rainfall and its associated phenomena to improve understanding of the Earth's climate system, weather patterns, and hydrological processes. The mission aimed to advance capabilities for rainfall measurement and prediction, particularly in tropical regions where precipitation plays a critical role in climate dynamics.