Nuclear thermal rocket engines are a type of rocket engine that use nuclear reactions to heat a propellant, typically liquid hydrogen, to generate thrust. These engines have the potential to provide much higher specific impulse, or exhaust velocity, than chemical rockets, allowing spacecraft to travel much faster and farther in space. However, nuclear thermal rocket engines also present several technical challenges, such as the need for advanced radiation shielding and the risk of nuclear contamination in case of a malfunction. Despite these challenges, nuclear thermal rocket engines remain an active area of research for potential use in future space exploration missions.