How SpaceX will Refuel on the Surface of Mars

With the plans that SpaceX has laid out, there are a number of logistical dogs that have not barked, as it were — implications about the order and nature of missions to enable how things work later on.

Refueling is a big one. The mission profile for a Starship traveling to Mars consists of the following phases:

1. Launch from Earth with Mars-bound payload, arriving in orbit with dry tanks
2. Refuel in orbit with multiple Starship tanker launches and rendezvous, topping off the tanks
3. Transfer orbit to Mars and land on Mars without orbital insertion.
4. MISSION
5. Refuel on the surface of Mars.
6. Launch from Mars and transfer orbit to Earth.
7. Land on Earth without orbital insertion.

The unmanned initial missions (2022) end at phase 4 — they are intended to remain on Mars indefinitely. But for the subsequent manned missions to return to Earth, the spacecraft will need to be fully refueled on the surface of Mars. This implies that before the crewed mission reached Mars, the infrastructure to perform this is in place — ideally, with a full set of fuel tanks sitting on Mars.

The Engineering and Its Implications