<p>This article examines (outer) Space as a new frontier for international business (IB) and highlights the unique challenges and opportunities it presents. Unlike terrestrial business environments, Space is characterized by extreme physical conditions, ambiguous property rights, and an institutional vacuum, which disrupt conventional IB theories. The study identifies three key challenges—congestion, contention, and competition—arising from the commercialization of Space and the increasing presence of multinational enterprises (MNEs) in the sector. Utilizing the OLI (ownership, location, internalization) framework, the paper critically reassesses existing IB theories, considering these Space-specific complexities and their long-term implications for global business strategy. Furthermore, it explores the geopolitical and regulatory implications of Space activities, arguing that the absence of effective governance structures necessitates novel policy frameworks and cooperative mechanisms to ensure responsible expansion. The study also underscores the role of MNEs in shaping sustainable Space commercialization, proposing the addition of a new 18th Sustainable Development Goal—Sustainable Space. The findings contribute to IB scholarship by advancing theoretical approaches that account for the spatial, institutional, and competitive dynamics unique to (outer) Space, offering a foundation for future research, policy development, and industry collaboration in the era of Space-based business and security expansion.</p>