The N-cycle bomb or nitrogen-cycle bomb was a doomsday weapon under development in the year 2266.
The bomb was being built aboard the Federation Research Satellite-5 space station. It was said to be capable of igniting the nitrogen cycle of a planet’s atmosphere, resulting in the complete destruction of the planet, which would also unbalance the gravity within that star system. The project team members called it “universal doomsday.” The bomb’s principles were theoretically proven by Professor Andres and then approved for development by the Federated Planets Weapons Committee, before it could be built by someone else. Team members included Andres and Dr. Njam. Other scientists potentially involved in the project were Lax and Steckler.
It was unclear if a working nitrogen cycle bomb was made. Only a prototype existed, according to Andres, who tried to prevent the manufacture and deployment of the bomb by hiding the device on Earth in the year 1955 by utilizing the time travel cabinet.
Njam killed Lax, then attempted to extort one billion credits from the Federation, claiming that it would be ransom to prevent the bomb from being detonated. Andres and the prototype were recovered by James T. Kirk and returned to the satellite. (TOS comic: "A Bomb in Time")