**Abstract**

Nuclear propulsion utilizes nuclear reactions to produce energy, which is then used to propel a vehicle. There are three main forms of nuclear propulsion: naval nuclear propulsion, aero-nuclear propulsion, and space nuclear propulsion. Naval nuclear propulsion involves the use of nuclear reactors to power ships. This propulsion type provides several advantages over traditional propulsion methods, including increased range, speed, and maneuverability. The first nuclear-powered submarine, the USS Nautilus, was commissioned in 1955, and since then, many countries have developed nuclear-powered submarines and ships. Aero-nuclear propulsion involves the use of nuclear reactors to power aircraft or missiles. This concept has been the subject of much research and development. Space nuclear propulsion involves the use of nuclear reactors to power spacecraft. This type of propulsion provides several advantages over traditional propulsion methods, including increased speed and efficiency. The main challenge with space nuclear propulsion is developing extremely high-temperature reactors.

**Keywords:** nuclear, thermal, electric, fission, fusion, propulsion
