Mars or Bust: The One-Way Reality of Settling the Red Planet

Jan de Vries · 2026-08-13

When we think about Mars colonization, it's easy to picture gleaming domes, heroic astronauts planting flags, and a fresh start for humanity. But there's a darker, more practical side to this dream that rarely makes the headlines. Harry Margulies, a keen observer of space exploration trends, recently dug into a question that should give every aspiring Martian pause: is this grand adventure actually a one-way ticket? ### The Gravity Problem Nobody Wants to Talk About Here's the thing about Mars that science fiction conveniently ignores: gravity. On Earth, you weigh about 185 pounds? On Mars, that same body would feel like just 70 pounds. Sounds kind of fun, right? Like a permanent carnival ride. But your body doesn't agree. Our muscles, bones, and even our hearts evolved over millions of years to function in Earth's gravitational pull. In Mars's low gravity, which is roughly 38 percent of what we experience here, your body starts to break down. Astronauts on the International Space Station already lose up to 1 percent of their bone density per month. That's a serious problem when you're planning to stay for years, not months. Margulies points out that settlers would face a brutal trade-off. You can't just "adapt" to low gravity like you'd adjust to a new climate. The changes are physiological, not psychological. Your body literally remodels itself, and not in a good way. We're talking about weakened hearts, brittle bones, and muscles that waste away despite daily exercise. ### The One-Way Trip Question So here's the uncomfortable question: if returning to Earth means enduring the crushing force of full gravity after years of living light, can anyone actually come back? The answer, according to Margulies' analysis, is probably not. Not safely, anyway. Think about it this way. Imagine spending a decade in a swimming pool, then suddenly being asked to sprint a marathon on dry land. That's the kind of shock a Martian settler's body would face upon returning to Earth. The heart, which has gotten used to working less hard, would suddenly have to pump against gravity it's forgotten how to handle. > "The first generation of Martians might be the last generation of Earth-returners," Margulies suggests. "We're not just colonizing a planet; we're creating a new branch of humanity." ### What This Means for the Mission If this reality sinks in, it changes everything about how we plan these missions. Here's what space agencies and private companies need to consider: - **Selection criteria**: We're not just picking the most skilled astronauts anymore. We're picking people willing to say goodbye to Earth forever. - **Mental health support**: Knowing you can never go home is a psychological burden that no amount of video calls can fix. - **Medical infrastructure**: Settlements need to be self-sufficient in healthcare from day one, because evacuation isn't an option. - **Ethical questions**: Is it fair to send people on a mission with no return ticket, even if they volunteer? ### The Silver Lining But here's the twist that keeps this dream alive. Maybe a one-way trip isn't a tragedy. Maybe it's the whole point. History is full of explorers who left their homelands knowing they'd never return. The Pilgrims, the pioneers crossing the American frontier, the Polynesians who sailed across the Pacific—they all committed to new worlds with no going back. Margulies frames it beautifully: Mars isn't just a destination. It's a declaration. We're not sending visitors; we're sending founders. And founders don't look back. They build. The real adventure, then, isn't about planting a flag and coming home to a parade. It's about accepting that some journeys are permanent. And for the right people, that's not a sacrifice. It's the greatest gift they could ask for. So, is Mars humanity's greatest adventure or a one-way trip? The answer might be both. And that's exactly why it matters.