Indeed, cosmic radiation is perhaps the biggest worry for the body in space. To give context to how bad it will be on the Red Planet: Ronke Mojoyinola Olabisi, an assistant professor in the department of biomedical engineering at the University of California, Irvine, who is working on the interdisciplinary human interstellar initiative, 100 Year Starship points out that on the ISS, [International Space Station], astronauts receive about 1,000 times the average yearly sea level dose of cosmic radiation. But once you head out farther, it's estimated to shoot up to 500,000 times. That in itself may end up speeding aging overall. Read More