Many Big Science projects and networks experience conflict. A plethora of disciplines have examined conflict causes in science collaboration and Big Science, contributing to a more nuanced... Show moreMany Big Science projects and networks experience conflict. A plethora of disciplines have examined conflict causes in science collaboration and Big Science, contributing to a more nuanced understanding of why conflicts emerge. Yet, so far, there is no theoretical model that explains which mechanisms connect conflict cause and outbreak in Big Science. Drawing on interdisciplinary literature on science collaboration and Big Science as well as on scholarship on strategic action fields (SAFs), I address this blind spot by proposing a model that outlines which mechanisms induce and fuel conflict in Big Science projects and networks. Five interlinked mechanisms – attribution of threat or opportunity, mobilization of resources, coalition-building, boundary deactivation and innovative action – are central to it. Tracing these mechanisms in conflictual episodes which emerged in three typical, yet most-different, Big Science cases – the International Experimental Thermonuclear Reactor (ITER), the Human Brain Project (HBP) and the Thirty Meter Telescope (TMT) – this study also provides a proof of concept for the model. Show less