On 12 February 2019 the NPOC Space Law Austria organized together with the Secure World Foundation the event “Guidelines for the Long-term Sustainability of Outer Space Activities: Implementation Experiences and Challenges” on the margins of the 56th session of the Scientific and Technical Subcommittee of UNCOPUOS. During its mandate from 2011-2018, the Working Group on the Long-term Sustainability of Outer Space Activities reached agreement on the texts of a Preamble and 21 Guidelines. The panel event focused on the implementation plans, experiences and challenges of a number of States with different levels of technical and regulatory capabilities in the space domain. States and Permanent Observers were invited to share their thoughts and experiences regarding the implementation of the Guidelines at the event.