THE MARTIAN CHRONICLES: How carrying enough water to make return-trip propellant simplifies a Starship mission to Mars.

The idea of a human mission to explore Mars has been studied repeatedly over the past 75 years. More than 1,000 piloted Mars mission studies were conducted inside and outside NASA between about 1950 and 2000. Many were the product of NASA and industry study teams, while others were the work of committed individuals or private organizations. I compiled a history of human mission studies through 2023. Essentially all of these mission design concepts were deemed impractical but now, if the SpaceX Starship proves flightworthy, new possibilities could finally emerge as the constraints on space travel change.

All of these studies were carried out in the era of constrained mass. Launch costs were high and minimizing mass sent to space was the main driver for mission design. To reduce mass, mission designs employed nuclear thermal propulsion (NTP), in-situ resource utilization (ISRU) to produce propellants for ascent from Mars and reliance on efficient recycling of gaseous and liquid wastes. Landing massive loads presented major challenges. The “initial mass in low Earth orbit” (IMLEO) was the dominant design parameter. None of these mission designs could be taken as practical and affordable, and a human mission to Mars remained a chimera of paper studies not going anywhere fast.

With the advent of reduced launch costs implemented by SpaceX, the rules of the game are changing. When the Starship becomes operational and can deliver 100 metric tons to Mars, we will have come full circle. The game is no longer to minimize mass, but rather to use large amounts of mass to reduce complexity and risk in moderate missions, and to pursue more ambitious missions than could previously be contemplated. The Starship will use chemical propulsion with a large amount of propellants. The political impediments of NTP are bypassed. It is claimed (but yet to be proven) SpaceX will be able to land huge loads on Mars.

Let’s get going on that next Starship flight test, please.