Kelly Weinersmith, biologist and writer: "Musk hopes to take a million people to Mars, but his rockets keep exploding."

Mars is cold, dry, and frequently plagued by dust storms that can last for weeks. It has no magnetic field to protect it from cosmic radiation, no oxygen , no breathable atmosphere, and its gravity is much lower than Earth's. And yet, Elon Musk claims that humans will establish the first Martian colonies in just 20 years, as groups of millionaires blast out of the atmosphere in ships from Jeff Bezos 's Blue Origin space company. Is the colonization of the solar system any closer?

Kelly Weinersmith (New Jersey, USA, 42) is a space-related writer and bioscience researcher at Rice University, where she studies parasites and how they manipulate the behavior of the hosts they infect. While researching An Elevator in Space (Blackie Books) with her husband, illustrator Zach Weinersmith, to write it, in which he analyzes the technologies that could become reality in the not-too-distant future, one of them, transporting materials to space more cheaply, became a reality with SpaceX, Elon Musk's space company. However, that is just one of the many problems posed by space colonization that its proponents, like Musk and Bezos, tend to ignore. Issues such as human reproduction outside of Earth, achieving an independent Martian economy, or the space laws that would regulate, or not, a future and, according to Weinersmith, improbable settlement on Mars. Thus, the couple wrote A City on Mars ( Penguin Random House ), which won the Trivedi Prize from Britain's Royal Society in October and reached the top of The New York Times bestseller list. Its publication in Spain is scheduled for October.

Question: Elon Musk claims we will land on Mars in four years and be able to live there in a self-sufficient city by 2050. However, Space X is having problems with its Starship rockets, which have exploded on the last three launches .

Answer: When we were researching Elevator to Space , we talked to people in the space industry, and they were excited because Space X was bringing down the cost of launching stuff into space, and they’ve really done an amazing job at it; it’s a lot cheaper now. Asteroid mining also seemed important. There were two big companies, Deep Space Industries and Planetary Resources, and when we interviewed the former, they said we were going to be mining asteroids and using them to build space colonies.

The space colonization advocacy community said it was the price of shipping all the resources we'd need—water, nitrogen, or phosphorus, for example—to grow plants that was holding us back. With that price solved with SpaceX and the possibility of extracting resources from asteroids, that should open the door to space settlements. However, asteroid mining has been somewhat forgotten. As for Musk, he hopes to use Starship to take a million people to the surface of Mars in the next 20 or 30 years, but his rockets keep exploding. They claim it's expected, and it's true; when testing new technologies, it's normal for some to fail. But the more we investigated, the clearer it became that getting materials into space is just one of many problems. We may be making great progress there, but not on the many other problems that would need to be solved to support a million people in space: how they could reproduce, feed themselves, create habitable ecosystems, think about possible legislation... What's a little frustrating is that Musk says his job is to get people into space and that other people should solve the other problems.

Q. Do space agencies share this vision?

A. I don't think NASA or the European Space Agency are very enthusiastic about space settlements; I don't see them allocating a lot of money. NASA recently conducted an experiment in which four people lived in a habitat for a year to study psychological and nutritional aspects related to life in space, but in general they aren't investing. It's mainly Bezos and Musk who are driving this talk and the investments.

Q. Why do you think Musk is talking about such short deadlines?

A. I don't think it's his responsibility to solve all the problems related to space settlements, but he does need to make sure we have solutions for them before sending people in. His timelines seem to me to reflect that he's either unaware of the other problems or that he thinks we should send people in and see what happens.

Q. It seems like we tend to ignore complexity in favor of simplicity these days. And if anything is complex, it's undoubtedly trying to live in an environment as hostile as space.

A: Yes, I think most people don't want complexities; they just want to know: Can I do this or not? And the answer is probably yes, but we have to answer a lot of questions first.

We've been invited to many conferences on space colonization. They often say, "We don't really want you here. You're a bit pessimistic, but you have valid arguments, so we're going to listen." We've been able to reach a large part of the settlement community, and they're willing to have these conversations, which is great. But then there are other people who corner you and say, "You can't stop me from going to space." I tell them I have no power to stop anyone from doing anything. And when I ask them if they aren't concerned about how little we know about how the human body will respond to the Martian environment, they sometimes respond, "You're a coward. It'll be fine." There's a long history of medical issues: the degradation of bones over time, muscles... Then there are other people who don't want to wait the decades it might take to accumulate the knowledge needed to determine what the risks are and how to minimize them. I once told someone, "I think if you go to the surface of Mars, you will die." He replied: “It’s okay, if I die on Mars, I’ll die happy.”

Q. You talk about how space settlements are seen as an escape from Earthly realities and a solution to all our problems: the climate crisis, social inequality... A Plan B for Earth.

A. Depending on the community you talk to, everyone has different answers about how space is going to solve our problems. Bezos argues that space is going to solve our environmental problems. We have too much population putting pressure on Earth, but if we could move billions of people into space, then we wouldn't have it anymore. But when you start analyzing the numbers, you immediately see that it doesn't make sense; we'd have to move about 200,000 people every day. How can you imagine being able to move that many people a day when the International Space Station typically holds ten people and doesn't even rotate? There's no way space can solve Earth's problems at all, nowhere near fast enough to save us from issues like climate change. We have to address Earth's problems directly. Space isn't going to help us.

Q. Another idea is that of philosopher Frank White, the “global perspective effect,” which assumes that going into space will make us ethically better.

A: Yes, the idea is that you go into space and, when you look at Earth, you're so struck by its beauty and apparent fragility that when you return, you'll care about environmental protection and less about political divisions because from space you've seen that there are no borders, which is false. You can see the border between India and Pakistan and the borders between North and South Korea. Our political problems are visible from space. And the astronauts' behavior when they return is like the rest of us: they cheat on their wives, they lie, they get angry with the opposing political faction... Space doesn't solve our problems; if anything, it might worsen some of them.

Q. For example?

A. If we end up fighting over territory on the Moon or Mars, it could increase geopolitical tensions between the United States and China, which aren't very good. And we're both nuclear superpowers. This new space race isn't just about setting foot on the Moon and coming back, but about setting foot and then staying there and perhaps extracting resources or establishing research stations. There are very few places on the Moon where you can get water from ice or where you can use solar panels for a long time. So you can imagine there will be a fight, and right now, international law isn't set up to deal with it.

Q. The 1967 Outer Space Treaty prohibits claims of sovereignty over all space.

A. That's true. The US couldn't, for example, land on the lunar south pole and say, "This crater belongs to us; it's now part of our nation." But it could get there first, land, and never leave. And according to the 2020 Artemis Accords, published by NASA and signed so far by about 50 nations , it can also declare a safety zone that no one can enter. And there's a good reason for having a safety zone: if another rocket landed nearby, it could send debris out at very high speeds, and since there's no atmosphere, they would travel fast and very far, potentially damaging equipment and people. So, it's reasonable to say we need to create a safety perimeter. But it seems like a question of sovereignty. So you can imagine there will be a fight for space, which will increase geopolitical tensions on Earth.

P. Musk states in the terms of his internet service, Starlink, that if they operate on Mars they will not be subject to Earthly laws.

A. That clearly violates international law. In space, you're still the responsibility of some nation. There are people who claim they're going to flout international law in space, and it's precisely these people who have the best chance of getting us there.