The development of the requirements for information exchange on space objects and events (now identified as UNISPACE+50 thematic priority three) has been accelerating from around the mid-2000s. However, it has yet to be highlighted that, for around 30 years, many proposals of these norms appeared repeatedly with many similarities in different international bodies. The purpose of this study is to better understand the chronology of the evolution of these norms, and to evaluate how and why certain current norms, specifically the “Guidelines for the Long-term Sustainability of Outer Space Activities” (“LTS Guidelines”), were able to evolve upon states reaching a consensus and agreeing upon formalized text, as compared to similar proposals in the past which failed to reach a consensus. Analyzing the conference room papers in the Ad hoc Committee (“AHC”) on the Prevention of an Arms Race in Outer Space (“PAROS”) in the Conference on Disarmament (“CD”) and the diplomatic records in Japan until the mid- 1990s, research shows that the following three proposals on Confidence Building Measures (“CBM”) of outer space (that were never implemented) ended up entering the discussion that led to the LTS Guidelines: (a) proposals on ensuring the immunity of satellites; (b) strengthening the Registration Convention; and (c) pre-launch notifications. This paper discusses the deliberative process of proposals (b) and (c) in the AHC, and how these two proposals later evolved into the LTS Guidelines on enhancing the practice of registering space objects as well as guidelines on pre-launch notification of space launch vehicles. It is noteworthy that, while the proposal on pre-launch notifications had gathered positive reactions in the AHC on PAROS, the US insisted that the issue be dealt with in the Missile Technology Control Regime (“MTCR”), which resulted in the formulation of the International Code of Conduct against Ballistic Missile Proliferation (also known as the Hague Code of Conduct or “HCOC”) after consultation with like-minded countries outside the UN. However, recently, these discussions regarding the current LTS Guidelines on pre-launch notification of space launch vehicles returned to be discussed at the UN and a consensus was partially reached. The HCOC is sometimes criticized by non-Subscribing States that it was formulated by the initiatives of non-UN countries that possess missile technology. However, the LTS Guidelines demonstrate that norms on prelaunch notification are also acceptable in the UN in the context of the safety of space activities. These findings indicate that the norms on outer space lie across multiple areas such as peaceful uses of outer space, disarmament, arms control and non-proliferation. They have gradually progressed to change the international arena, slowly and intermittently.