Toward the Most Accurate Thermometer in Space: FORMOSAT-7/COSMIC-2 Constellation

FORMOsa SATellite mission-2/Constellation Observing System for Meteorology, Ionosphere, and Climate mission-2 (FORMOSAT-7/COSMIC-2) is a Taiwan-U.S. collaborative mission between the National Space Organization of Taiwan and the National Oceanic and Atmospheric Administration (NOAA) of the United States. The mission aims to collect more than 4000 global navigation satellite system radio occultation (RO) sounding profiles at low- and middle-latitude regions every day with 30-minute data latency. The satellite constellation consists of six small satellites with each one having a weight of 300 kg. The satellites are planned be launched in 2019 to bridge the potential FORMOSAT-3/COSMIC (launched in April 2006) RO data gap and improve accuracy of the severe weather forecast. The raw data is free for users around the world to download. The advantage of constellation observation is to provide the capability to sense large amounts of data simultaneously across different parts of the globe. Through the deployment of a constellation of satellites, data users can obtain geographically homogenous distributed measurements for space weather and atmospheric weather estimation. This article presents an overview of the FORMOSAT-7/COSMIC-2 constellation mission, its impacts, and technical challenges of the spacecraft design.