SOLAR was an ESA science observatory on the Columbus Laboratory, which is part of the International Space Station. SOLAR was launched with Columbus on February 2008 aboard STS-122. It was externally mounted to Columbus with the European Technology Exposure Facility (EuTEF). SOLAR has three main space science instruments: SOVIM, SOLSPEC and SOL-ACES. Together they provide detailed measurements of the Sun's spectral irradiance. The SOLAR platform and its instruments are controlled from the Belgian User Support and Operations Centre (B.USOC), located at the Belgian Institute for Space Aeronomy (BISA) in Uccle, Belgium.

Columbus is a science laboratory that is part of the International Space Station (ISS) and is the largest single contribution to the ISS made by the European Space Agency (ESA).