Six identical micro-satellites comprising the FORMOSAT-3/COSMIC (Formosa Satellite #3 and Constellation Observing System for Meteorology, Ionosphere and Climate) mission were successfully launched into a circular low-Earth orbit from Vandenberg Air Force Base, California at 01:40 UTC on April 15, 2006. The FORMOSAT-3/COSMIC mission is a collaborative project jointly carried out by the National Space Organization (NSPO) in Taiwan and the University Corporation for Atmospheric Research (UCAR) in USA, with the participation of many governmental, academic and private institutions. Each FORMOSAT-3 satellite carries three primary science instruments: a GPS Occultation Experiment (GOX) payload, a Tiny Ionospheric Photometer (TIP), and a Tri-Band Beacon (TBB) payload. The GOX provides vertical sounding of atmospheric profiles around the globe and electron density profiles in the ionosphere. The TIP instrument is a narrow band far-ultraviolet radiometer; it operates in the 131.0 - 160.0 nm bandwidth with a focus wavelength at 135.6 nm to measure the line-of-sight total electron content. The TBB transmits phase coherent, continuous signals at three frequencies: VHF (150.012 MHz), UHF (400.032 MHz), and L-band (1066.752 MHz) to provide ionospheric observations to ground-based receivers.