Resolves YES if any device meant to cause an explosion via a nuclear reaction is detonated at least 100 km above Earth's surface before the end of 2050. This does not include times that this has happened before the market was created (both the U.S. and the Soviet Union tested nuclear weapons in space before nuclear test ban treaties prohibited it).

It doesn't necessarily have to be a nuclear weapon. A nuclear explosive used for any purpose will count (e.g., destroying or redirecting asteroids that endanger Earth, nuclear thrusters, space mining). A device powered by a nuclear reactor doesn't count, even if that device is used to generate explosions - it has to be a nuclear explosion.