Question: When do you think humans will be able to live on Mars?

Abbie Hutty answered on 24 Feb 2020:

We have the technology for human to live on Mars now – if we made a base a bit like the ISS, but underground where it was protected from the radiation at the surface, it could be quite similar. It would just take a lot of separate rocket launches and missions to get all the equipment and habitat components, as well as food and water and things- over there, as well as needing some pretty extreme robots to assemble it all once it was there, and either cover it with Mars soil or somehow dig it into the ground!. We can only really launch things to Mars every two years, when the orbits of Earth and Mars come close together – so that is another factor that would slow down progress. And even the biggest rockets still have a maximum size and weight of thing that they can lift into space – so we would also have to have all the stuff broken into chunks that fitted on rockets, and then either assembled in space or down on the surface of Mars. All those rockets would be hugely expensive and take a lot of fuel! If we really wanted to and we had the funding, we could design these things in the next 10 years or so, and maybe be building and sending them with 15-20. We don’t currently have any funding though, so we aren’t even working on anything yet!

The next – and major – thing is getting human beings there in the first place. We don’t really have a way of doing this safely yet – as we don’t really have any technologies that would protect the people from the radiation exposure during the journey through deep space. This means that by the time they got to Mars, they might be incurably ill, or even dead. That is the major area that we will have to develop- by some combination of improved shielding, faster propulsion systems to speed up journey times, and so on, to bring this risk to an acceptable level. This could take decades- or we could have a breakthrough in the next few years which could make a big improvement fast. That’s the area that it is very difficult to predict.

Another difficulty is getting humans safely back to Earth. We have never launched anything from another planet and brought it back to Earth, let alone humans. The mission I am working on now – the Mars Sample Return mission, aims to do this for the first time in roughly 2030. Depending on how this goes this may help prove the technology that we would need – but it is only launching a football-sized thing into space, not a crew capsule big enough to keep astronauts alive, so again there is a lot of technology that needs to be developed there before that would be possible – and a mission is much less likely to get funding if we didn’t think we could bring the people back safely afterwards, as fundamentally nobody is keen on watching fellow humans die all alone on another planet.

My guess is that we will send humans in the next 25 years or so, but for very basic missions, maybe limited to staying within a small capsule in Mars orbit before returning to Earth (without going down to the surface) or something like that. As for larger missions, actually on the surface, where they actually “live”, and are able to do fun stuff like leave the habitat to walk around on the surface, eat fresh food grown on Mars, conduct science experiments, and could come home again safely, rather than just surviving miserably in a very cramped and uncomfortable environment, then maybe 50. But these are just wild guesses and depend on lots of factors – mostly how much money is invested in trying, and how soon.