The commons are defined by non-excludability – the idea that none can exclude another from access or use. Likewise, space lawyers portray their discipline’s origin story as uniquely egalitarian and inclusive, in part because of how it was made. The 1963 Principles Declaration and 1967 Outer Space Treaty were drafted by a committee of 28 states that decided by consensus – the first permanent UN body to do so. They worked in the midst of significant colonial and Cold War tensions to form a body of law which implicated the interests of every state. This article argues that the lawmaking which made space ‘common’ was made possible by excluding the Third World. It uses historical sources from 18 archives to shed new light on the process of making space law from 1957 to 1967. Based on this, it explores various factors, from UN documentation practices to American racial segregation, that cumulatively prevented Third World representatives from meaningful participation in space lawmaking. These factors had broad impacts on the drafting committee’s membership, attendance, decision-making procedure, and final products. By seeking to understand this ‘small history’ of a niche field at a specific historical moment, this article also adds to ongoing work that questions the axioms by which international lawyers interpret treaties today.