Don't Leave Home Without It: Planetary Protection for Robotic and Human Missions

In planetary exploration and the search for life beyond Earth, the unique capabilities provided by human explorers will be advantageous to science only if the biological contamination associated with human presence is understood and controlled. The practice of preventing cross- contamination between the Earth and other planetary bodies is called planetary protection. NASA has a planetary protection policy in place for solar system exploration missions, and compliance with it is mandatory. Thus, planetary protection must be incorporated in mission planning and development from the beginning. NASA's planetary protection policy is intended to prevent "forward contamination", contamination of other solar system bodies by Earth microbes and organic materials, and "backward contamination", contamination of Earth by potential alien life. As NASA's space exploration program expands to encompass human as well as robotic planetary missions, planetary protection will become a more complicated enterprise.