Curiosity Rover has been able to use the Radiation Assessment Detector (RAD) to determine that surface levels of radiation are not immediately lethal to humans. Apparently, Mars’ light atmosphere reduces the radiation dose to less than what is encountered in interplanetary space. The atmosphere actually thickens as the heat from the Sun warms it during the Martian day and this causes greater protection from the Sun’s radiation. This is good news, as no other planetary body’s radiation levels have been monitored so closely and frankly, we weren’t exactly sure if an extended surface excursion on Mars would be deadly or not.
Coronal Mass Ejections (CME) in particular. The CME’s are related to the 11 year cycle of activity that the Sun goes through and is expected to peak near mid 2013. That is good because we want to measure radiation at or near the solar maximum, as those are most likely to be the most dangerous times for humans on Mars. Once we know what to expect, it is possible to protect ourselves from some, if not all of the radiation. Studies on colonizing the Moon, which has no protective atmosphere, have shown that manageable amounts of soil serve as a protective barrier to solar radiation. If we plan to make temporary or permanent housing, building it either underground or with a thick covering of soil should be enough to make the stay on Mars possible while reducing health risks.
553 days. While further tests are needed to find evidence of life, at least we know that as far as radiation goes, it just might be possible. This is also good new for terraforming, as certain bacteria may contribute to the early terraforming stages and we now know that they can either survive or be engineered to survive the radiation of Mars.
Now that we know what we need to safely survive on the surface, we can make better estimates of what we will need to bring with us to ensure the safety of our astronauts. The goal isn’t just to get astronauts to Mars but to also get them home safely. This information from the Curiosity Rover is invaluable in regards to that goal.