This volume on the Solar Radiation and Climate Experiment (SORCE) mission continues a Solar Physics tradition of special topical issues dedicated to major solar space missions. As one element of NASA's Earth Observing System, SORCE is a satellite carrying four instruments to measure the solar radiation incident at the top of the Earth's atmosphere. These observations are improving our understanding and generating new inquiry regarding how and why solar variability occurs and how it affects our atmosphere and climate. The SORCE mission is a joint effort between NASA and the Laboratory for...