A NASA-sponsored minisatellite mission, launched on 25 January 2003, from Cape Canaveral, into a circular orbit that crosses the equator at 40°, at a height of 645 km. SORCE carries four instruments, the total irradiance monitor (TIM), spectral irradiance monitor (SIM), solar stellar comparison experiment (SOLSTICE), and the extreme ultraviolet photometer experiment (XPS). These provide precise measurements of solar radiation in the UV and visible and near-infrared (VNIR) wavebands, providing data to help understand the influence of variations in solar radiation on climate.

https://earth.esa.int/web/eoportal/satellite-missions/s/sorce SORCE (Solar Radiation and Climate Experiment).