The accords set out a shared framework for safe, transparent and cooperative civil space activities, as interest in lunar and planetary exploration continues to expand among governments and private industry.
NASA administrator Jared Isaacman welcomed Portugal’s decision, describing it as part of a new era of global cooperation in space.
“Portugal joins a group of nations building the foundations for safe, transparent and prosperous activity in space,” Isaacman said in recorded remarks. “This is our generation’s golden age of exploration, driven by innovation, international collaboration and a shared commitment to discovery.”
Portugal’s Secretary of State for Science and Innovation, Helena Canhão, formally signed the accords on 11 January on behalf of the Portuguese government.
Hugo Costa, executive director of the recently established Portuguese Space Agency, said the timing of the signing carried particular significance.
“2026 will be the year humans return to the moon, marking the start of a new era of space exploration,” Costa said. “It echoes the spirit of Portugal’s great explorers, such as Ferdinand Magellan and his circumnavigation of the globe. As a nation committed to sustainability and responsibility in space, Portugal is proud to join the Artemis Accords and contribute to the peaceful and beneficial use of space for all humankind.”
A ceremony to mark the signing was held in Lisbon during a semi-annual meeting between the United States and Portugal focused on bilateral cooperation.
US ambassador to Portugal John J Arrigo said the accords played an important role in shaping the future of space activities.
“This is a significant step towards responsible space exploration,” Arrigo said. “Shared principles like those in the Artemis Accords help ensure space remains a domain of stability, safety and opportunity for all nations.”
The Artemis Accords were established in 2020 during the first Trump administration, led by NASA and the US Department of State, with eight founding signatories. They were developed in response to increasing interest in lunar exploration and the need for common rules to guide civil space activity.
The accords outline practical principles, including peaceful and transparent exploration, mutual assistance in emergencies, open access to scientific data, non-interference with the activities of others, protection of historic sites and artefacts, and the development of best practice standards for exploration.
More countries are expected to join the Artemis Accords in the months and years ahead as international cooperation in space continues to expand.