Outer Space Treaty (OST), 1967

The Outer Space Treaty (OST), 1967 is the basic law of outer space, often called the "Magna Carta of space". It is an international treaty that says space is free for all countries to explore and use, no country can own any part of it, and nuclear weapons must not be placed in orbit or in space. The Moon and other celestial bodies (planets, asteroids) must be used only for peaceful purposes. Almost every later rule about space is built on this treaty.

Why does it exist?

In 1957, the Soviet Union launched Sputnik, the first artificial satellite. Suddenly, the two superpowers of the Cold War, the US and the Soviet Union, were racing into space. Many countries feared three things:

• that one power might claim the Moon or other bodies as its own territory, like colonies on Earth;
• that space might become a new battlefield, with nuclear bombs circling the Earth;
• that only the rich, powerful countries would control space, leaving others out.

The OST was written to stop these dangers before they happened. Think of it as the rules of a new playground agreed on before any game begins: everyone can play, nobody can fence off a corner, and nobody can bring weapons of mass destruction.

Where did it come from?

• 1959: The UN set up the Committee on the Peaceful Uses of Outer Space (COPUOS) as a permanent body to discuss space rules.
• 1963: The UN General Assembly adopted the Declaration of Legal Principles on space activities (Resolution 1962 (XVIII)). It was not binding, but its ideas later became the OST.
• 19 December 1966: The General Assembly endorsed the treaty text (Resolution 2222 (XXI)).
• 27 January 1967: The treaty was opened for signature in Washington, London and Moscow. The US, the UK and the Soviet Union (now Russia) are its depositary governments (the countries that keep the official copies and records of who has joined).
• 10 October 1967: The treaty entered into force.
• India signed the treaty on 3 March 1967 and ratified it (formally accepted it as binding) on 18 January 1982.
• As of October 2025, about 118 countries were parties, including every major space-faring nation, and about 20 more had signed but not ratified.

The key articles of the treaty

The OST has 17 articles. These are the ones UPSC likes most:

• Article I (freedom and benefit for all): Exploring and using space must be done for the benefit of all countries, whatever their level of development. Space is "the province of all mankind" and is free for all to explore.
• Article II (no ownership): No country can claim space, the Moon or any celestial body as its own, whether by declaring sovereignty, by using or occupying it, or by any other means. This is called the non-appropriation principle.
• Article III: Space activities must follow international law, including the UN Charter.
• Article IV (no weapons of mass destruction): Countries must not place nuclear weapons or any other weapons of mass destruction in orbit around the Earth, on celestial bodies or anywhere in space. The Moon and other celestial bodies must be used exclusively for peaceful purposes: no military bases, no weapons testing and no military exercises there.
• Article V (astronauts): Astronauts are "envoys of mankind". Countries must help astronauts in distress and return them safely.
• Article VI (state responsibility): Each country is internationally responsible for all its national space activities, whether done by the government or by private companies. Private space activity needs authorisation and continuing supervision by the government.
• Article VII (liability): A country that launches an object, or from whose territory it is launched, is liable (must pay) for damage that object causes to another country or its people.
• Article VIII (jurisdiction): A country keeps control over the space objects it has registered, and over the people on board.
• Article IX (due regard and no contamination): Countries must act with "due regard" for others' interests, avoid harmful contamination of space and of Earth, and consult others before any activity that might cause harmful interference.

The family of space treaties

The OST was followed by four more UN treaties, which spell out its ideas in detail:

1. Rescue Agreement, 1968: on rescuing astronauts and returning space objects.
2. Liability Convention, 1972: on paying for damage caused by space objects. It makes the launching country absolutely liable for damage on the Earth's surface or to aircraft in flight.
3. Registration Convention, 1975: countries must register their space objects with the UN.
4. Moon Agreement, 1979: declares the Moon and its resources the "common heritage of mankind". Very few countries have joined it, and none of the major space powers is a party.

India has ratified the OST, the Rescue Agreement, the Liability Convention and the Registration Convention. It has signed but not ratified the Moon Agreement.

How does the treaty work in practice?

The OST has no police force and no court of its own. It works through countries' own laws and through diplomacy. For example, under Article VI, a private Indian company that wants to launch a satellite must get permission from the Indian government. In India, this permission is given through IN-SPACe (Indian National Space Promotion and Authorisation Centre), set up in 2020.

The Indian Space Policy, 2023 opened space activities to private firms within this framework. If an Indian satellite damaged another country's satellite, India, not just the company, would be answerable under international law. Countries also register their satellites with the UN Office for Outer Space Affairs (UNOOSA) in Vienna, which serves COPUOS.

India's position and Indian examples

• India has always backed the OST and the idea of space as a shared resource for all humanity.
• On 27 March 2019, under Mission Shakti, India destroyed one of its own satellites (Microsat-R) in low Earth orbit at about 300 km using an anti-satellite (ASAT) missile built by the DRDO. India became the fourth country, after the US, Russia and China, to show this ability. India said the test broke no international law, because the OST bans only weapons of mass destruction in space, not all weapons.
• In June 2023, India signed the US-led Artemis Accords, a non-binding set of principles for Moon exploration, becoming the 27th country to do so. The Accords say they are consistent with the OST.

Commonly confused concepts

• OST vs Moon Agreement: The OST is widely accepted and binding on almost all space powers. The Moon Agreement goes further, calling the Moon's resources the "common heritage of mankind", but very few countries have joined it.
• OST vs Artemis Accords: The OST is a binding UN treaty. The Artemis Accords are a non-binding political agreement led by the US, built on the OST.
• What Article IV bans and what it does not: Article IV bans nuclear weapons and other weapons of mass destruction in orbit and in space, and all military activity on the Moon and celestial bodies. It does not clearly ban ordinary (conventional) weapons in orbit or ground-based anti-satellite missiles. This gap is why the PAROS debate exists.
• OST vs Partial Test Ban Treaty (1963): The 1963 treaty bans nuclear test explosions in the atmosphere, in outer space and under water. The OST bans placing nuclear weapons in space.

Issues, criticism and the way forward

• Gaps on weapons: The treaty does not ban conventional weapons, ASAT missiles, lasers or cyber attacks on satellites. As military use of space grows, this gap has become serious.
• Space resources: Article II bans national ownership of celestial bodies, but it is unclear whether private companies can own resources they mine. The US (2015) and Luxembourg (2017) passed laws allowing their companies to own mined space resources. Critics say this goes against the spirit of the treaty.
• Private players: The treaty was written for a world where only governments went to space. Today thousands of satellites belong to private companies, so national authorisation and supervision under Article VI matter more than ever.
• Space debris: The treaty has no clear rules on debris, even though debris from tests and collisions threatens all satellites.
• Way forward: Experts suggest updating the rules through COPUOS, building clear national space laws, agreeing on norms for debris and traffic management, and negotiating new treaties to fill the weapons gap.

Concepts to Know

• Celestial body: Any natural object in space, such as the Moon, planets, asteroids and comets.
• Ratification: The formal step by which a country, after signing a treaty, agrees to be legally bound by it.
• Weapons of mass destruction (WMD): Weapons that can kill very large numbers of people at once, mainly nuclear, chemical and biological weapons.
• Anti-satellite (ASAT) weapon: A weapon designed to disable or destroy satellites, for example a missile fired from the ground.
• Low Earth orbit (LEO): The region of space up to about 2,000 km above Earth, where most satellites and space stations fly.
• Depositary government: A country that keeps the original treaty and the official records of which countries have signed and joined.