Scientists Aim to Protect Astronauts from Deadly Space Radiation

A woman wearing a prototype of Stemrad's new protective vest, Astrorad, sits inside the Excalibur-Almaz Space Capsule during a demonstration at the National Museum of Science Technology and Space in Haifa, Israel on February 23. Amir Cohen/Reuters

Radiation. It’s everywhere, from the fallout of nuclear weapons to medical X-rays. It’s a cause of cancer, but it’s also one of the preferred forms of cancer treatment. There’s also a lot of it in space, and if we want to send astronauts to Mars safely, that’s a problem.

The charged particles commonly called radiation are a serious threat to anyone traveling in space, whether it’s a stay on the International Space Station or beyond. The Earth’s magnetic field protects people on the planet from radiation by trapping the particles in radiation belts that surround the globe. These doughnut-shaped areas in space, called Van Allen belts, lie up to 36,000 miles from the Earth’s surface. Within Earth’s orbit, astronauts are protected, but you can’t get to the moon, Mars or beyond without venturing past them. Once astronauts travel through and beyond the Van Allen belts—hazards in and of themselves because they trap these harmful particles—their bodies become vulnerable.

Deep space astronauts have to contend with two types of radiation. The first is composed of galactic cosmic rays, high-energy particles that travel at close to the speed of light. These cosmic rays, which are mostly protons but can also be composed of heavier elements, can damage human DNA, trigger mutations and change gene transcription. When gene transcription occurs, DNA produces RNA, which carries the instructions from DNA to the cells in the body. When that process is changed, RNA carries imperfect instructions to the cells. Over the medium and long term, these errors can become permanent mutations.