The Outer Space Treaty is a key international agreement that sets out the fundamental principles guiding the exploration and use of outer space.

1. Outer Space for All: The exploration and use of outer space shall be carried out for the benefit of all countries, regardless of their level of economic or technological development.

2. Prohibition of National Appropriation: Outer space, including the Moon and other celestial bodies, cannot be claimed by any nation as their own territory. No sovereignty can be exercised over any part of outer space.

3. Peaceful Purposes:Outer space shall only be used for peaceful purposes. The establishment of military bases, testing of weapons, or any other kind of military activity is prohibited.

4. International Responsibility: States are responsible for national space activities, whether carried out by governmental or non-governmental entities. They are also liable for any damage caused by their space objects.

5. Freedom of Exploration: States are encouraged to collaborate in the exploration and use of outer space. They are also required to provide assistance to astronauts in distress and to conduct their activities so as to avoid harmful contamination of celestial bodies.

6. Moon and Celestial Bodies: The Moon and other celestial bodies are to be used exclusively for peaceful purposes. Any activity on these bodies must adhere to the principles of cooperation and avoiding harmful contamination.

7. Astronauts as Envoys of Mankind: Astronauts are considered as envoys of all humankind and should be treated with respect and provided with all necessary assistance.