Titan, Saturn’s largest moon, has long intrigued scientists due to its nitrogen-rich atmosphere, methane lakes, and complex organic chemistry. It is now being considered as a future destination for crewed missions beyond Mars, according to a recent study presented at the Lunar and Planetary Science Conference (LPSC 2025).
Researchers William O’Hara and Marcos Fernandez-Tous propose that nuclear-fission propulsion could make a crewed mission to Titan feasible. Their study evaluates propulsion systems that could reduce travel time and limit astronaut exposure to microgravity and cosmic radiation.
Unlike Mars, which lies 0.5 astronomical units (AU) from Earth, Titan is approximately 8.5 AU away. The study emphasises the need for faster transit times to overcome the health risks posed by long-duration space travel.
The researchers assessed both nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP). They examined NASA’s DRA 5.0 concept, which outlines an NTP spacecraft for Mars, and NASA’s Copernicus design, which allows for heavier propellant loads to reach deep space destinations.
The Copernicus vehicle could potentially reduce one-way travel to Titan to around 90 days with additional fuel tanks. However, this would significantly increase the spacecraft’s total mass and mission cost, raising questions about practicality.
The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) and Direct Fusion Drive (DFD) were also evaluated. These electric propulsion methods could reduce one-way transit to under 150 days but would require further adaptation for human missions.
Explore Titan, the group behind the proposal, advocates extending NASA’s “Moon to Mars” strategy into a “Mars to Titan” initiative. They argue that technology developed for Mars could be adapted to explore Titan, offering the next step in human space exploration.