**5. Conclusions**

This chapter has provided an overview of the concept of nuclear thermal propulsion for interplanetary travel. Nuclear thermal propulsion has a significant advantage in efficiency over current chemical rocket technologies, providing the opportunity to complete a trip to Mars in half the time previously anticipated, reducing exposure time for the spaceship crew. It also offers more options for mission abort if needed.

NTP was first conceived shortly after the end of World War II. Materials development programs and construction and operation of experimental facilities began in the 1950s under Project Rover, which was taken over by NASA shortly after its formation. Rover served as the basis for NASA's Nuclear Engine for Rocket Vehicle
