 The cluster mission was launched in 2000 as ESA's first cornerstone project, along with SOHO. Two Russian Soyuz rockets were used to deliver two cluster spacecraft into their proper orbits. The four satellites reached their final tetrahedral constellation by the end of August 2000. The mission's main goal is to study small-scale plasma structures and keep plasma regions, such as the solar wind and auroral zones. Cluster plays a major role in the International Solar Terrestrial Program, ISTP, and has state-of-the-art plasma instrumentation to measure electric and magnetic fields and electron and island distribution functions. The science operations are coordinated by the Joint Science Operations Center, JSOC, at Rutherford Appleton Laboratory and implemented by ESOC in Darmstadt, Germany. A network of eight national data centers has been set up for raw data processing and physical parameter production. This article was authored by C. P. Escobar, M. Feringer, and M. Goldstein. We are article.tv. Links in the description below.