Limited Test Ban Treaty of 1963, aka the Atmospheric Test Ban Treaty
The Outer Space Treaty of 1967 forbids the militarisation of space.
The Nuclear Test Ban Treaty (1963) prohibits nuclear weapons tests in the atmosphere, outer space, and underwater. Therefore, testing of nuclear weapons has not been conducted in these environments as per the treaty's stipulations. However, underground tests are permitted under the treaty, leading some countries to continue such activities while adhering to the treaty's terms.
As of now, the U.S. does not have weapons stationed in space, but it does possess various military satellites used for communication, surveillance, and navigation. The U.S. government has expressed interest in developing capabilities to protect its space assets and deter potential threats, leading to discussions about space-based defense systems. However, the Outer Space Treaty of 1967 prohibits the placement of nuclear weapons and other weapons of mass destruction in space, which constrains the deployment of offensive weaponry.
The treaty that stopped nuclear testing in the atmosphere was the Partial Nuclear Test Ban Treaty, signed in 1963 by the United States, the Soviet Union, and the United Kingdom. This treaty prohibited nuclear testing in the atmosphere, underwater, and in space, helping to reduce the environmental and health risks associated with nuclear weapons testing.
On August 5, 1963, representatives of the United States, Soviet Union and Great Britain signed the Limited Nuclear Test Ban Treaty, which prohibited the testing of nuclear weapons in outer space, underwater or in the atmosphere.
That is called the Partial Test Ban Treaty. It was signed in 1963 and banned the testing of nuclear weapons in the atmosphere, outer space, and underwater.
I think you are refering to the 1963 Limited Nuclear Test Ban Treaty. On August 5, 1963, after more than eight years of difficult negotiations, the United States, the United Kingdom, and the Soviet Union signed the Limited Nuclear Test Ban Treaty. The Treaty: prohibits nuclear weapons tests or other nuclear explosions under water, in the atmosphere, or in outer space allows underground nuclear tests as long as no radioactive debris falls outside the boundaries of the nation conducting the test pledges signatories to work towards complete disarmament, an end to the armaments race, and an end to the contamination of the environment by radioactive substances.
The Limited Test Ban Treaty of 1963 aimed to eventually end contamination of the environment by radioactive substances. The Test Ban Treaty of 1963 prohibits nuclear weapons tests "or any other nuclear explosion" in the atmosphere, in outer space, and under water. While not banning tests underground, the Treaty does prohibit nuclear explosions in this environment if they cause "radioactive debris to be present outside the territorial limits of the State under whose jurisdiction or control" the explosions were conducted. In accepting limitations on testing, the nuclear powers accepted as a common goal "an end to the contamination of man's environment by radioactive substances."
On December 8, 1966, the USSR and the United States signed a treaty saying no nuclear weapons in space.
On August 5, 1963, representatives of the United States, Soviet Union and Great Britain signed the Limited Nuclear Test Ban Treaty, which prohibited the testing of nuclear weapons in outer space, underwater or in the atmosphere.
There is not just one nuclear arms treaty... there are a number of treaties currently in place between the U.S., Russia, and many other countries dealing with nuclear weapons. Some have to do with banning testing (whether above ground, below ground, or in space), some with banning their construction. Other treaties deal with an attempt to keep existing weapons from getting into the hands of other nations ('non-proliferation') and the most encouraging treaties are concerned with significantly reducing the existing nuclear stockpiles to a much smaller number that is easier to maintain, control and monitor.
Prohibits nuclear weapon test explosions and any other nuclear explosions in three environments: in the atmosphere, in outer space and underwater, but does not prohibit underground nuclear explosions