Chapter 10: Planetary Protection-History, Science, and the Future

Planetary protection is a principle in the design of interplanetary missions that aims to prevent biological cross contamination between the target body and Earth. Planetary protection policies and procedures have worked to mitigate forward contamination (from Earth) and back contamination (to Earth) since the beginning of the space age. Today, planetary protection policy is guided by international agreements, nongovernmental advisory councils, and national space agencies. The landscape of planetary protection science and policy is changing rapidly, as new technologies, crewed missions to Mars and the Moon, and even orbital settlements are being developed. Space exploration, whether specifically targeted toward questions in astrobiology or not, must consider planetary protection concerns to minimize contamination that poses a risk to both astrobiological investigations as well as Earth's biosphere. In this chapter, we provide an introduction to and overview of the history, motivations, and implementation of planetary protection in the United States.