 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 by July and August of that year. The four satellites reached their final tetrahedral constellation by the end of August. The commissioning of 44 instruments was completed five months later, ensuring optimal use of their observational potential. The mission was declared operational on February 1, 2001. The main goal of the cluster mission is to study small-scale plasma structures in three dimensions in key plasma regions such as the solar wind, bow shock, magnetopause, polar cusps, magnetotail, and auroral zones. The payload consists of state-of-the-art plasma instrumentation to measure electric and magnetic fields from quasi-static up to high frequencies, and electron and ion distribution functions from energies nearly zero EV to a few MEV. The science operations are coordinated by the Joint Science Operations Center, JSOC, at Rutherford Appleton Laboratory in the U.K. and implemented by the European Space Operations Center, ESOC, in Darmstadt, Germany. A network of eight national data centers has been set up for raw data processing, physical parameter production, and distribution to end-users worldwide. The latest information on the cluster mission can be found at robotic-underscore-exploration-clustered-a. This article was authored by C. P. Escobar, M. Feringer, and M. Goldstein. We are article.tv, links in the description below.