Mars exploration and planetary protection - what do we need to know to avoid an unwanted contamination?

Kurzfassung

Planetary protection is an international effort governed by the UN Outer Space Treaty with two aims: (i) to secure the ongoing and future scientific exploration of planets and moons of astrobiological interest by avoiding their contamination with terrestrial organisms and organic molecules and (ii) to protect the Earth-Moon system from potential harmful effects of extraterrestrial material carried by spacecraft returning from interplanetary missions. Committee on Space Research's (COSPAR) Planetary Protection Policy has defined different planetary protection categories depending on the target body and type of mission. Mars is of high astrobiological interest. Mars lander missions fall into category IV with subcategories depending on whether the mission incorporates life detection instruments and depending on the chosen landing site. In view of the present knowledge about the environmental conditions on Mars and about the limits of microbial life on Earth the current planetary protection requirements for Mars were assessed thereby taking the biocidal effects of the martian environment, the stability of water on the surface of Mars and the aeolian transport of particles into account. Several knowledge gaps have been identified that need to be addressed before any changes can be made to the existing planetary protection policy. These gaps must be filled through further research and investigation in order to justify any modifications to the current requirements.