Human life ‘sustainable on Mars in 300 years’, says author
Image credit: National Geographic
Writer Stephen Petranek, whose book ‘How We’ll Live on Mars’ inspired the new National Geographic docu-drama ‘Mars’, tells E&T that SpaceX, not Nasa, is likely to lead the human mission to Mars in the not-so-distant future. He also believes there will be no return mission, as terraforming the Red Planet is the way forward to ensure survival of humanity.
Petranek visited London for the unveiling of a Mars home at the Royal Observatory Greenwich, which has been built based on concepts explored in his book and the Mars series.
E&T: So how exactly will we live on Mars?
Stephen Petranek: We think of housing on Earth as providing a certain amount of shelter, but on Mars you will essentially live in a survival capsule that will be providing the oxygen you need to breathe, it will suck the humid Martian atmosphere in and take the water out of it so you have water supply. It will protect you from solar radiation and from cosmic rays.
Martian homes will have walls almost 5m thick, made of bricks made of Martian soil. In fact, Nasa has developed a machine where you take a little bit of plastic and mix it with Martian regolith, which is what we call the soil on Mars, and you put it in a form and pop it in a microwave and you got a brick.
E&T: The Martian home at the Royal Observatory Greenwich has a large window, but will real Martian habitats have windows?
Stephen Petranek: There will be no windows, just the thick walls. We will have light tubes bringing sunlight in. These light tubes bring only the light but not the harmful radiation, which is a big concern on Mars because the atmosphere there is only one hundredth as thick as it is on Earth so you don’t have this absorbing blanket that blocks solar rays and at the same time you don’t have the magnetosphere that we have on Earth.
E&T: Who will build those houses?
Stephen Petranek: These houses will be built by labourers and workers on Mars, the astronauts. People will literally build their own homes on Mars. Everything will have to be built mostly from materials that are available on Mars because we can’t afford to bring most of the materials from Earth. But we can recycle parts of the spacecraft, for example its airlocks.
E&T: You said the house will use components from the spaceship that has brought the astronauts to Mars. Does that mean they are not coming back to Earth?
Stephen Petranek: That’s correct. It costs so much money to take a person to Mars that you pretty much have to assume that these are one-way trips. You want to build a civilisation on Mars and that will take tens of thousands, if not millions of people, so you don’t want people to be going to Mars who are only going there for a vacation, you don’t want people going to Mars who are saying to themselves, well I will see whether I like it and maybe I’ll come back. You want people who are really committed to this project, who are coming to build a new world, a new society, who are coming to stay.
E&T: But aren’t the current plans more about a return trip to Mars and back to Earth?
Stephen Petranek: It depends on whose plans you are talking about. Entities like Nasa or the European Space Agency would like to send astronauts to do an initial exploration. But my bet is they are not going to be the first to get there.
E&T: Who is going to be the first on Mars if not Nasa?
Stephen Petranek: I think it will be SpaceX. SpaceX is a company that is only ten years old. Ten years ago, they didn’t have a flyable rocket and now they are one of the most successful rocket companies in the world. They can launch large objects into the orbit around the Earth, they can send probes to the Moon if they want and in 2018 they are going to send a rocket to Mars and try to do a vertical landing on Mars with their rocket. They are the first company in the world that has been able to recycle their first stages. They are way ahead of everybody else. That company was established for the only one mission, which is to create a sustainable civilisation on Mars. They have a passion and the determination and that’s their soul mission, to get people to Mars and to create a sustainable civilisation and I think they are going to do it.
E&T: Are you suggesting that in this greatest adventure of mankind, the giants of the past are going to play second fiddle?
Stephen Petranek: I think that’s quite right. Space is now becoming the province of private companies and it’s happening very quickly. You no longer need a government to get you into space. You no longer need the Russians to get you into space, you don’t need the Ariane space programme to get you into space, you don’t need Nasa to get you into space. SpaceX can do that, Orbital Sciences can do that. There is a number of companies moving into this area very quickly.
E&T: Let’s return to the Marsonauts. You said they will be using local resources; do you think the Martian society will be self-sustainable?
Stephen Petranek: That will take a couple of hundreds of years. We will send a lot of cargo before they even arrive and there will be resupply ships coming from Earth all the time. Mostly, they will be bringing freeze-dried food because we cannot grow enough food on Mars until we start terraforming the planet.
E&T: Can’t we grow food in a greenhouse on Mars?
Stephen Petranek: That’s very inefficient. You would have to have so much space and it has to be pressurised. It also has to be protected from radiation. The only way to really grow enough food on Mars is to grow it outside. You can’t grow it outside until you have a warmer climate.
E&T: Are you suggesting mankind will try to trigger global warming on Mars?
Stephen Petranek: Exactly. The way you create warmer climate is to start warming the frozen carbon dioxide around the poles. You do that with a large solar mirror, which will be in stationary orbit around Mars and will be focused on the south pole. The large quantities of frozen carbon dioxide on Mars are just barely frozen. In fact, they are not always frozen throughout the year so if you can warm it up just a little, four or five degrees, suddenly, you would make the atmosphere much thicker. Once you make the atmosphere thicker, you retain heat from the Sun and you begin heating up the planet. You create basically what we don’t want on Earth, which is a runaway greenhouse effect. Once you have a warmer planet, you can have running water. There is a lot of frozen water on Mars. You would have running water in the band around the equator. Once you have running water and a thicker atmosphere and the atmosphere has carbon dioxide, which plants love, then you can start growing food outside to sustain the population, but that’s probably a hundred years away.
E&T: How long will it take to make living on Mars the way it is on Earth?
Stephen Petranek: If you have an unlimited amount of money and put up the solar mirrors as soon as you have people on Mars, you can have running water on Mars and a much warmer planet within as little as a few decades. But since we are unlikely to have the money, we are going to do this gradually over a period of time. I think that the process of terraforming of Mars will probably take place over 100 to 300 years.
E&T: Are you saying that in 300 years, people will live on Mars the way they do on Earth?
Stephen Petranek: Living on Mars will always be different - for example because the gravity of Mars is only 38 per cent of the gravity of Earth. Even with all the terraforming, the Martian atmosphere will not be breathable for at least a thousand years. But with the exception of the breathable atmosphere, within 300 years, you can have a planet that feels a lot more like Earth, where you have running water in streams that might freeze at night. It might be a climate that’s very similar to Canada, for example. You can have trees, you can have plants and you can have significant agriculture. I suppose you can even have domesticated animals to some extent, if you keep them in a pressurised environment.