Network analysis of international cooperation in space 1958–2023: Evidence of space blocs

The future of international cooperation in outer space was questioned when, in January 2022, Russia announced that it intended to leave the International Space Station (ISS) in 2024. A symbol of post-Cold War reconciliation, the station has linked Washington and Moscow even when relations on the ground frayed. The ISS has become a bedrock of international cooperation, having welcomed 276 individuals from 22 countries since it was first put in orbit in 1998. Russia’s announced departure from the ISS alarmed proponents of international cooperation in space. Its actions, however, do not signal an end but a new phase in international cooperative dynamics in space. This article examines international cooperation in outer space from 1958 until 2023. Using network analysis, it quantifies cooperative relations between states on space matters to examine the current state of international cooperation in space and its evolving dynamics. It finds that international cooperation in space has become increasingly defined by the emergence of distinct clusters of states, termed ‘space blocs’. Recent patterns of international cooperation in space markedly deviate from past dynamics in three key aspects. First, since 2008, distinct, bound space blocs can be clearly detected. Second, the internal composition of recent space blocs has become increasingly reflective of geopolitical affinities and strategic considerations on the ground. Third, although highly bound and distinct, the more recent space blocs are not entirely isolated and have not instituted any exclusionary practices, which is promising for the future of international space cooperation.