When Elon Musk announced that SpaceX was going to start crewed missions to Mars in the 2020s, it was a cause for excitement and celebration: in just a few short years, we’d all have the chance to become colonists on the Red Planet! Well, it turns out that you probably wouldn’t arrive on Mars as a bold pioneer if you went today—you’d probably get there as a bed-ridden cancer patient with a gut full of tumors. A new study has discovered that long-term space voyages have the potential to expose astronauts to a lot of heavy radiation, and we don’t have a way to stop that, at least for now.
The research exposed mice to low levels of heavy ionizing radiation for long periods of time and found that the cells in the gastrointestinal tract were particularly susceptible to developing cancer from it. Ionized iron and silicon were identified as being especially damaging, and according to Kamal Datta, the study’s senior investigator, there’s not much we can do about them: “With the current shielding technology, it is difficult to protect astronauts from the adverse effects of heavy ion radiation. Although there may be a way to use medicines to counter these effects, no such agent has been developed yet.”
One the reasons the GI tract is so vulnerable is because the cells in it are constantly being replaced by the body. If radiation disrupts this cycle, the rapidly growing cells may turn into cancer. The longer astronauts spend in space, Datta says, the more likely that prospect becomes: “While short trips, like the times astronauts traveled to the Moon, may not expose them to this level of damage, the real concern is lasting injury from a long trip such as a Mars or other deep space missions which would be much longer.”
Elon Musk has already said that “people will die” on the first SpaceX mission </a>to Mars, but ideally it’ll be from something we didn’t plan for. We doubt anyone’s going to sign up to be the first Martian if they know the deal involves getting some free stomach cancer on the way there.