The foundational legal principle in Article l (para one) of the 1967 Outer Space Treaty provides that the exploration and use of outer space, including the Moon and other celestial bodies. shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development. This principle, which is often referred to as the ‘common benefit’ principle, has .been reiterated in both the Preamble and the operative part of the Outer Space Treaty, thus, making it binding upon all State Parties to the Outer Space Treaty. It was the Brazilian delegation ‘0 the United Nations Committee on Peaceful Uses of Outer Space (U NCopuos), which insisted on the inclusron of the Kcommon benefit' principle in the operative part of the 1963 Declaration of Legal Pflntlples Governing the Activities of States in the Exploration and Use of Outer Space which was the precursor of the Outer Space Treaty. Thus, Brazil played a critical role in the drafting of the Outer Space Treaty. After over 50 years since the Outer Space Treaty entered into force, it is opportune to examine this legal principle, particularly in a Iiber amicarum honouring Prof. Jose Monserrar Filho, from Brazil, a distinguished leader in the field of international space law. This paper will examine the origin and meaning of the ‘common benefit' principle, its foundational importance in the global space governance system, and its challenges in contemporary legal and geopolitical thinking for exploration and use of outer space, including the Moon and other celestial bodies. Finally, this paper makes some recommendations for future actions that the international community should take in order to main- tain, strengthen and implement the ‘common benefit' principle.The focus of this paper is that Article 1 (para one) of the Outer Space Treaty is binding upon all State Parties, imposing a positive obligation on States which they must fulfill in good faith, though the nature and extent ofits implementation are left to the discretion ofthe sovereign Sta- tes. This paper emphasizes that the effectuation of the ‘common benefrt' principle can only mate- rialize through cooperation amongst spacefaring and non-spacefaring nations. Thus, all States are obligated to make good faith efforts to cooperate realisation and assuring that the exploration and use of outer space benefit all countries rather than a few space-faring nations.