Could Mars Become a One-Way Trip for Its First Settlers?

Jan de Vries · 2026-08-13

Harry Margulies has been digging into one of the biggest questions of our time: will Mars colonisation turn into a one-way trip for the brave souls who sign up? It's a thought that sticks with you, especially when you consider what low gravity does to the human body over years, not just months. We're not talking about a quick vacation. We're talking about building a life 140 million miles away from home, on average. That distance alone changes everything, from how you get there to how you'd ever get back. And for some experts, the answer might be that you simply wouldn't. ### The Gravity Problem Nobody Wants to Talk About Here's the thing: Mars has about 38% of Earth's gravity. That sounds manageable until you realize what it means for bones, muscles, and even your heart. Astronauts on the International Space Station lose bone density at about 1-2% per month, and that's in microgravity. On Mars, it's less severe, but it's still a fraction of what your body evolved for. After a year or two on the surface, your body would start adapting in ways that make a return to Earth genuinely dangerous. You'd be weaker, your bones would be more fragile, and your cardiovascular system would have recalibrated to a lighter workload. Landing back in Earth's gravity could feel like carrying a car on your shoulders. ### The Adaptation Argument Some researchers argue that this isn't a bug; it's a feature. If we're serious about becoming a multi-planetary species, then settlers who commit to staying might actually be the smartest approach. They'd adapt fully to Martian life, raise families there, and build a society that doesn't look back. - Children born on Mars would develop with low gravity as their baseline. - Their muscle tone, bone density, and even height could differ from Earth norms. - Returning to Earth might be physically impossible for them, not just difficult. That's a profound thought, right? A generation that physically cannot visit the planet their parents came from. It turns colonisation from an adventure into a permanent decision, one that echoes through bloodlines. ### The Psychological Side of a One-Way Ticket Let's not ignore the mental weight of knowing you'll never see Earth again. Even if you're thrilled about the mission, there's a difference between visiting somewhere and knowing it's your final home. Isolation, distance, and the inability to just hop on a flight back could take a serious toll on even the most resilient minds. Margulies suggests that mission planners need to think about this as much as they think about life support systems. A colony that's mentally broken isn't a colony; it's a disaster waiting to happen. ### What This Means for the Future If Mars colonisation becomes a one-way trip by design, we're not just sending explorers anymore. We're sending founders of a new branch of humanity. That changes the conversation around ethics, consent, and what we owe the people who go. It's a heavy topic, but it's one worth having before the first boots hit the red dust. Because once they're there, coming home might not be an option, no matter how much we wish it was. So, is Mars humanity's greatest adventure? Maybe. But it could also be the most permanent decision we've ever made as a species. And that's something we all need to understand before we sign anyone up for the ride.