Committee on Planetary Protection – författare

Under U.S. policy and international treaty, the goals of planetary protection are to avoid both adverse changes in Earth''s environment caused by introducing extraterrestrial matter and harmful contamination of solar system bodies in order to protect their biological integrity for scientific study. The United States has long cooperated with other countries and relevant scientific communities through the Committee on Space Research (COSPAR) of the International Council for Science in developing planetary protection guidance for different categories of space missions. In the past, achieving planetary protection objectives through science-based, international-consensus guidelines proved relatively straightforward because a small number of spacefaring nations explored the solar system, predominantly through government-led and scientifically focused robotic missions.

However, interest in, and the capabilities to undertake, exploration and uses of outer space are evolving and expanding. More countries are engaging in space activities. Private-sector involvement is increasing. Planning is under way for human as well as robotic missions. As recent advisory reports have highlighted, the changes in the nature of space activities create unprecedented challenges for planetary protection.

This publication responds to NASA''s request for "a short report on the impact of human activities on lunar polar volatiles (e.g., water, carbon dioxide, and methane) and the scientific value of protecting the surface and subsurface regions of the Earth''s Moon from organic and biological contamination." It provides an overview of the current scientific understanding, value, and potential threat of organic and biological contamination of permanently shadowed regions (PSRs), lunar research relevant to understanding prebiotic evolution and the origin of life, and the likelihood that spacecraft landing on the lunar surface will transfer volatiles to polar cold traps. It also assesses how much and which regions of the Moon''s surface and subsurface warrant protection from organic and biological contamination because of their scientific value.

Since the 1980s, national and international planetary protection policies have sought to avoid contamination by terrestrial organisms that could compromise future investigations regarding the origin or presence of Martian life. Over the last decade, the number of national space agencies planning, participating in, and undertaking missions to Mars has increased, and private-sector enterprises are engaged in activities designed to enable commercial missions to Mars. The nature of missions to Mars is also evolving to feature more diversity in purposes and technologies. As missions to Mars increase and diversify, national and international processes for developing planetary protection measures recognize the need to consider the interests of scientific discovery, commercial activity, and human exploration. The implications of these changes for planetary protection should be considered in the context of how much science has learned about Mars, and about terrestrial life, in recent years.

At the request of NASA, this report identifies criteria for determining locations on Mars potentially suitable for landed robotic missions that satisfy less stringent bioburden requirements, which are intended to manage the risk of forward contamination.

The ultimate goal of planetary protection for outbound missions is to prevent harmful contamination that would inhibit future measurements designed to search for evidence of the existence or evolution of extraterrestrial life. Preventing harmful contamination is achieved by following specific guidelines based on existing scientific knowledge about the destination and the type of mission. This report responds to NASA''s request for a study on planetary protection categorization of missions to small bodies, including whether there are particular populations of small bodies for which contamination of one object in the population would not be likely to have a tangible effect on the opportunities for scientific investigation using other objects in the population. In addressing NASA''s request, the authoring committee considered surface composition of target bodies and their importance for prebiotic chemistry, along with size of the small-body populations, the current state of knowledge on the types of objects, the likelihood of a future scientific mission returning to any specific object, active object surface processes, and the size.