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From our Expert Voices conversation on travel to Mars.

Projecting the health risks to astronauts from exposure to space radiation remains a largely unsolved problem, raising concerns about cancers, circulatory diseases, cataracts and changes to cognition and memory.

The potential harmful effects are qualitatively different from those of exposure to radiation on Earth, like X-rays, since space radiation involves heavy ions and secondary neutrons, which have been shown to induce distinct damage to cells and tissues. While space missions always carry risks, these threats to human health are still not well enough understood to be factored into current risk projection models.

One way to know: Because the current number of astronauts is small and past space missions have been relatively short, research using experimental models at particle accelerators, which can simulate space radiation, is likely our best method to make progress. We now have a solid understanding of shielding materials and space environments, but a sustained biomedical research program of 2000 beam hours per year over a decade, as advocated by the U.S. National Research Council, is still needed to understand the long-term effects of exposure.

The bottom line: Advancements in biophysics, cancer biology, and neuroscience are necessary not only to accurately predict health risks, but also to create biomedical countermeasures and sufficiently understand our genetic vulnerability to the unique types of radiation in space.

Other voices in the conversation:

Go deeper

Senate Republicans shrug off debt default deadline

Treasury Secretary Janet Yellen testifies before House members Wednesday. Photo: Al Drago/Bloomberg via Getty Images

Senate Republicans are feeling far more relaxed about the impending Dec. 15 federal debt-default deadline this time around, with many suggesting the real drop-dead date isn't until January.

Why it matters: Their attitude toward the deadline set by Treasury Secretary Janet Yellen is distinctively different from the hair-on-fire rhetoric before the initial Oct. 18 date. But a Congress discounting the advice of a Treasury secretary is risky financial practice — and has the potential to affect markets itself.

12 mins ago - Politics & Policy

GOP fights itself on shutting down government over vaccine mandates

Reporters question Senate Minority Whip John Thune before the Republican Party's weekly lunch on Tuesday. Photo: Kent Nishimura/Los Angeles Times via Getty Images

GOP leaders on Capitol Hill are scrambling to reach a deal with a bloc of 15 Senate Republicans threatening a government shutdown to force a fight over the Biden administration's vaccine mandates.

Why it matters: The push to defund the mandates — by holding the short-term government funding bill hostageis largely symbolic, and highly controversial within the Republican Party. A shutdown as early as midnight Friday could trigger everything from national park closures to delays in receiving Social Security checks.

Progressives call for swift Boebert punishment

Reps. Alexandria Ocasio-Cortez and Cori Bush (far right) walk through the Capitol last month. Photo: Kent Nishimura/Los Angeles Times via Getty Images

House progressives are seeking concrete punishment for Rep. Lauren Boebert (R-Colo.) as retribution for her incendiary remarks against one of their own, Rep. Ilhan Omar (D-Minn.).

Why it matters: House Democratic leaders continue to consider their options amid the latest ugly incident in their chamber. Republicans are already threatening retaliation after Democrats stripped Rep. Marjorie Taylor Greene (R-Ga.) of her committee assignments and censured Rep. Paul Gosar (R-Ariz.).