Comparison of radiation doses – includes the amount detected on the trip from Earth to Mars by the RAD inside the MSL (2011–2013).[16][17][18] Vertical axis is in logarithmic scale, so the dose over a Mars year is about 15 times the DOE limit, not less than twice, as a quick glance might suggest. The actual dose would depend on factors such as spacecraft design and natural events such as solar flares.