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The Cluster mission was the first constellation using four identical spacecraft to study Sun‐Earth connection plasma processes. Using four spacecraft in a tetrahedron shape, it could measure, for the first time, 3D quantities such as electrical currents, plasma gradients or divergence of the electron pressure tensor and 3D structures such as boundaries, surface waves or vortices. Launched in pairs in July and August 2000, on two Soyuz rockets from Baikonur, the four spacecraft have been collecting data continuously for more than 20 years. The mission faced many challenges during the years of operations as some spacecraft subsystems had a lifetime of a few years beyond the initial two‐year mission. The major one was to operate without functioning batteries and to successfully pass short and long eclipses, up to 3 h long, without damaging the on‐board computers and transmitters and without freezing the fuel. More than 1,000 eclipses have been successfully passed since 2010 using a specially made procedure which switches off the complete spacecraft before entering into eclipse and switches it on when the Sun is again illuminating the solar panels. During 20 years, many discoveries and science results have been published in more than 2,700 scientific papers. A few highlights are presented here, focusing on how varying the spacecraft separation was essential to achieve the science goals of the mission. The Cluster Science Data System and the Cluster archive allows public access to all science data as well as spacecraft ancillary data.

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ESA's interplanetary missions Rosetta, Mars Express and VenusExpress have common on-board software, which includes an On-board Control Procedure (OBCP) execution system. These OBCPs are managed on-board as binary files stored in the Mass Memory and in the central computer RAM, possibly in several copies for redundancy purposes. On ground, the source files and compiled output have historically been stored in a variety of places, from version control tools to shared network drives. Jointly the missions identified a need to consolidate into a unified system, capable of supporting the different approaches to OBCPs as adopted by each mission. In parallel to the configuration management aspects, the development of new OBCPs has migrated to a procedure-based methodology which allows OBCP creation in a manner more consistent with the procedure development interface more familiar to ground controllers . The intention is for spacecraft operations engineers to be able to generate new OBCPs without any particular programming skill. Although developable without software background, the OBCPs represent modifications to spacecraft on-board autonomy with major function and potentially critical impact. Thus the new configuration management system needs to integrate with the procedure generation tool and enable rapid end-to-end development while maintaining strict version control as required by onboard software. This paper presents the requirements derived for such a multi-mission system, the implemented solution common to the ESA planetary missions, and lessons learned.