The year is 2066. The sun rises dimly in a rust-coloured sky, lighting up the hydroponic fields. In the first permanent habitat on Mars, intrepid explorers are waking up to start another 24.5-hour day.
Elon Musk thinks it’s possible. In September, the SpaceX founder unveiled his (still somewhat vague) plan for sending humans to Mars in the next decade or so, and suggested that we might have a million people living full-time on the Red Planet by the 2060s. NASA’s more conservative plan sees the first humans going there in the 2030s.
We’ll have to get moving. Before settlers can start building a life, we would need to set up everything they need to merely survive on the surface. This means launching tonnes of life-support equipment, habitats, energy-generation systems, food, and technology for extracting breathable oxygen and drinkable water from the air.
That’s a huge challenge. The shortest journey time between Earth and Mars is roughly five months, but that would only be possible around once every two years when the planets align with one another. In the most optimistic scenario, this gives us about 22 ideal launch opportunities to lay the groundwork for human settlement by 2060.
And as the recent failure of the ExoMars lander (right) shows, landing on Mars is tricky: it has enough gravity to accelerate a craft’s descent, but such a thin atmosphere that parachutes won’t slow it down enough. The heaviest thing that ever landed on Mars, the 1-tonne Curiosity rover, used a combination of parachutes, retrorockets and a daredevil dangling device called a sky crane.
Given that we don’t know …