# Outer Space Treaty The Outer Space Treaty is the founding document of international space law. Negotiated at the [[United Nations]] during the [[Cold War]], it opened for signature on 27 January 1967 and took effect that October. The United States, the Soviet Union and Britain were its original depositaries. 116 countries have ratified it, including every country with a significant space program. It was written when only two countries could reach orbit, both governments, both armed with nuclear weapons. Nearly sixty years later, most activity in space is commercial, and the treaty's broad principles are being stretched to cover mining, megaconstellations and missile defense. ## What it says - **No national claims.** No country can claim sovereignty over the Moon or any other celestial body (Article II). - **No weapons of mass destruction in orbit.** Nuclear weapons and other weapons of mass destruction may not be placed in orbit, on the Moon or anywhere else in space. The Moon and other celestial bodies are to be used "exclusively for peaceful purposes," with no military bases or weapons tests there (Article IV). - **States answer for their companies.** Governments are responsible for space activities by their own companies and citizens, and must authorize and supervise them (Article VI). - **Liability and freedom of access.** Space is open to all countries, astronauts are "envoys of mankind," and countries are liable for damage their space objects cause. ## Where it's being tested **Space mining and property.** The treaty bans claiming territory but says nothing clear about owning what you dig up. The U.S. answered that question for itself in 2015, when Congress gave American companies the right to own resources they extract in space. A 2020 executive order from [[Donald Trump]] said the U.S. does not view space as a "global commons." The [[Artemis Accords]] build that reading into a multinational agreement. Critics, including Russia and China, call it a way around the ban on claims. **Nuclear weapons in orbit.** In 2024, U.S. officials said Russia was developing a nuclear anti-satellite weapon, which would violate Article IV. In April 2024 Russia vetoed a UN Security Council resolution reaffirming the ban. See [[Anti-Satellite Weapons]]. **Missile defense.** The treaty bans weapons of *mass destruction* in orbit, not conventional weapons. The [[Golden Dome]] plan for space-based interceptors that destroy missiles by collision is therefore legal under the treaty, but it pushes against the treaty's spirit that space should not become a battlefield. ## Why it's on the map The Outer Space Treaty is the baseline against which every space-policy fight in this wiki should be measured. It is also a rare example of the United States and the Soviet Union agreeing, at the height of the Cold War, that some things were too dangerous to compete over. Today's pressures from both sides — American commercial and military ambitions, Russian nuclear threats, and China's growing capability — test whether that agreement still holds. ## See also - [[Artemis Accords]] — the U.S.-led rules built on the treaty - [[Anti-Satellite Weapons]] — the weapons the treaty only partly covers - [[Golden Dome]] — space-based missile defense - [[The Moon]] — the lunar-resource race - [[Nuclear Non-Proliferation Treaty]] — the companion arms-control framework - [[Space Hub]] — the parent hub