"Radiation doses accumulated by astronauts in interplanetary space would be several hundred times larger than the doses accumulated by humans over the same time period on Earth, and several times larger than the doses of astronauts and cosmonauts working on the International Space Station," Jordanka Semkova, a physicist at the Bulgarian Academy of Sciences and lead scientist on the new research, said in a statement. “Our results show that the journey itself would provide very significant exposure for the astronauts to radiation.”

At the same conference – which winds up on Friday, September 21 – another team of scientists working on the orbiter project released new images of the surface of Mars, taken as a monster dust storm begins to subside. Read also: Why scientists are building a 'Martian garden' in Switzerland

The storm reduced light levels on the planet so significantly that NASA’s solar-powered Opportunity rover was out of action for three months. The ExoMars pictures, taken on September 2 by the Colour and Stereo Surface Imaging System or CaSSIS aboard the orbiter, were compared with images of the same regions taken by NASA’s Mars Reconnaissance Orbiter in March and there was little evidence of streaks then.
The ExoMars Trace Gas Orbiter reveals dust devils in the Mars region Ariadnes Colles. New measurements indicate astronauts traveling to Mars would experience 60% of their recommended career exposure to radioactivity in a single roundtrip journey.