The Tropical Rainfall Measuring Mission (TRMM) is a joint space mission between NASA and the Japan Aerospace Exploration Agency (JAXA) designed to monitor and study tropical rainfall.
The term refers to both the mission itself and the satellite that the mission uses to collect data. TRMM is part of NASA's Mission to Planet Earth, a long-term, coordinated research effort to study the Earth as a global system.
The satellite was launched on November 27, 1997 from the Tanegashima Space Center in Tanegashima, Japan.