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SORCE mission graphic

Solar Radiation and Climate Experiment

Phase: Operating

Launch Date: January 25, 2003

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Program(s):Earth Systematic Missions

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SORCE is a NASA-sponsored satellite mission that will provide state-of-the-art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. SORCE represents the merging of the EOS Solar Stellar Irradiance Comparison Experiment (SOLSTICE) and the Total Solar Irradiance Mission (TSIM). The measurements provided by SORCE specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. These measurements are critical to studies of the Sun, its effect on our Earth system, and its influence on humankind.

Solar radiation is the dominant, direct energy input into the terrestrial ecosystem, and it affects all physical, chemical, and biological processes. The Sun provides a natural influence on the Earth's atmosphere and climate. In order to understand mankind's roles in climate change, the Sun's impact must first be understood.

SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolometers engineered into instruments mounted on a satellite observatory. The SORCE satellite orbits around the Earth accumulating solar data. Spectral measurements identify the irradiance of the Sun by characterizing the Sun's energy and emissions in the form of color that can then be translated into quantities and elements of matter. Data obtained by the SORCE experiment will be used to model the Sun's output and to explain and predict the effect of the Sun's radiation on the Earth's atmosphere and climate.

The SORCE spacecraft launched on January 25, 2003 on a Pegasus XL launch vehicle to provide NASA with precise measurements of solar radiation. It launched into a 645 km, 40 degree orbit and is operated by the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado. It will continue the precise measurements of total solar irradiance (TSI) that began with the ERB instrument in 1979 and has continued to the present with the ACRIM series of measurements. SORCE will also provide the measurements of the solar spectral irradiance from 1nm to 2000nm, accounting for 95% of the spectral contribution to TSI. SORCE carries four instruments including the Total Irradiance Monitor (TIM), Solar Stellar Irradiance Comparison Experiment (SOLSTICE), Spectral Irradiance Monitor (SIM), and the XUV Photometer System (XPS).