“…As a result, Mars has a higher flux of ultraviolet radiation at wavelengths shorter than 290 nm, which is usually the most biologically harmful type (Cockell et al, 2000(Cockell et al, , 2005. An increase in UV-B radiation will have potentially detrimental effects on earth organisms when they are brought to Mars for terreforming and for establishing CELSS (Closed Ecological Life Support system) in spaceflight (Wang et al, 2004a(Wang et al, ,b, 2006, especially for photoautotrophs that require solar light for energy and biomass synthesis. There is abundant evidence of the adverse effects of UV-B radiation on living organisms, including dimerization of pyrimidine bases, membrane damage, protein destruction and hormone inactivation (Palmer et al, 2002;He et al, 2002;He and Häder, 2002b).…”