Nasa is developing ways to use nuclear power to send spacecraft to their destinations. Nuclear propulsion could greatly reduce the journey time to Mars, perhaps cutting a voyage of more than six months to three or four months.
The idea of nuclear propulsion in space goes back to the cold war. But Nasa has been pursuing it more aggressively since billionaire and commercial astronaut Jared Isaacman took over as the agency’s chief in December 2025. Isaacman is a well-known advocate of the technology and says it can “truly unlock humankind’s ability to explore among the stars”.
