Special PR observation experiments during the TRMM satellite descending

The Tropical Rainfall Measuring Mission (TRMM) is a joint venture between the National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). The TRMM spacecraft was launched on November 27, 1997. In August 2001, TRMM was boosted to a higher operational altitude of 402.5 km from the initial one of 350 km, to save fuel and extend the mission life. On July 8, 2014, a significant pressure drop during the orbit maintenance maneuver indicated the exhaustion of the onboard propellant. Precipitation Radar (PR) cannot collect the scientific meaningful data by the usual operation between the satellite altitudes of 402.5 km to 350 km. In order to obtain useful knowledge on development of future space borne precipitation radar, the special observation experiments were done during the TRMM satellite descending.