The Nasa Tropics Mission as a Pathfinder for Future Operational Earth Observing Systems

The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROP-ICS) mission was selected by NASA as part of the Earth Ven-tureInstrument (EVI-3) program and flight hardware has been delivered for a launch in the 2021-2022 timeframe. TROP-ICS comprises a constellation of six CubeSats in three low-Earth low-inclination orbital planes. Each CubeSat will host a high performance radiometer to provide temperature profiles using seven channels near the 118.75 GHz oxygen absorption line, water vapor profiles using three channels near the 183 GHz water vapor absorption line, imagery in a single channel near 90 GHz for precipitation measurements (when combined with higher resolution water vapor channels), and a single channel at 205 GHz that is more sensitive to precipitation-sized ice particles. A seventh (spare) flight unit has also been delivered that could serve as the seventh element in the constellation or could be launched in advance of the primary mission for checkout of key system performance. The TROPICS mission highlights a number of aspirations of future earth observing sysems, including high revisit rate, system resilience, rapid technology infusion, and low cost. This paper presents these elements with an eye toward future operational architectures for weather and climate monitoring.