National Academies Press: OpenBook
« Previous: Front Matter
Suggested Citation:"Executive Summary." National Academies of Sciences, Engineering, and Medicine. 2020. Report Series: Committee on Planetary Protection: Planetary Protection for the Study of Lunar Volatiles. Washington, DC: The National Academies Press. doi: 10.17226/26029.
×

Executive Summary

This report from the Committee on Planetary Protection (CoPP) 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.”1 NASA specifically asked the committee to include in its report the following:

  1. 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; and
  2. An assessment of how much and which regions of the Moon’s surface and subsurface warrant protection from organic and biological contamination because of their scientific value

In fulfilling this task, the committee applied the definition of planetary protection that NASA has used for decades, namely,

  1. The control of forward contamination, defined as the control of contamination from biological or organic materials that might interfere with the search for life in the solar system; and
  2. The control of back contamination, defined as the control of extraterrestrial materials collected from other solar system bodies and returned to Earth.2

Current scientific understanding is insufficient for the committee to issue clear findings on some aspects of its charge. However, minimizing and mitigating the potential confounding impact on PSRs is important, so as to avoid obscuring an important scientific record preserved in the volatile deposits. Potential contamination mitigation steps that merit further attention include using spacecraft emissions modeling in combination with laboratory, remote sensing, and in-situ data, to tailor individual mission planetary protection approaches; characterizing the signature of exhaust volatiles; use of spacecraft witness plates; and implementing contamination mitigation protocols during sampling.

The committee considered different sources of organic and biological contamination of the lunar surface and subsurface from robotic and crewed missions, including rocket exhaust from landers, outgassing from vehicles and structures, and venting from spacesuits. Given the limited time available to the committee to complete its analyses, the committee focused on rocket exhaust from landers as the most significant, and most readily modelled, potential source of organic contamination. Given the scope of planetary protection policy, the committee focused on possible direct and indirect contamination of the surface and subsurface of PSRs because these regions: (1) are of most interest for scientific investigations of how lunar volatiles inform the processes of prebiotic chemistry; and (2) act as “cold traps” that can capture and preserve scientifically important volatiles from natural and anthropogenic sources.

The existing science indicates that biological contamination of the lunar surface and subsurface is not a threat to scientific investigations of the Moon relevant for planetary protection purposes, such as studies of prebiotic chemical processes. In terms of volatiles, surface contamination of all lunar regions

___________________

1 See the statement of task to the committee, reprinted in Appendix A.

2 National Academies of Sciences, Engineering, and Medicine, 2018, Review and Assessment of Planetary Protection Policy Development Processes, The National Academies Press, Washington, DC, https://doi.org/10.17226/25172.

Suggested Citation:"Executive Summary." National Academies of Sciences, Engineering, and Medicine. 2020. Report Series: Committee on Planetary Protection: Planetary Protection for the Study of Lunar Volatiles. Washington, DC: The National Academies Press. doi: 10.17226/26029.
×

from human activities, such as rocket exhaust, is likely, but the risk of contaminating subsurface deposits in PSRs from vertical transport through natural processes is low. However, little is actually known about the composition, distribution, and transport of volatiles on the Moon, especially concerning surface and subsurface areas of PSRs. Scientific investigations are urgently needed to provide “ground truth” measurements about volatiles on and underneath PSRs in order to inform the development of appropriate and effective planetary protection strategies.

The committee’s specific findings are as follows:

Finding 1: The scientific potential of the Moon’s poles and PSRs is significant, including for studies of prebiotic chemical evolution that have long been within the scope of national and international planetary protection policy.

Finding 2: Understanding of the lunar poles and PSRs has advanced but remains incomplete concerning many scientific questions, including how cold traps on the lunar surface function with respect to volatile and organic chemicals, the nature and composition of water and other volatile deposits in PSRs, and how the water and other ice deposits inform the scientific understanding of prebiotic chemical evolution in the solar system.

Finding 3: Tapping the scientific potential of the lunar poles and PSRs requires accelerating lunar science across orbital and in situ missions and building “ground truth” about these regions to inform planning for planetary protection approaches for future scientific, exploration, and commercial activities on the Moon.

Finding 4: Inventories of biological materials for spacecraft and other lunar equipment are unimportant for planetary protection purposes because (1) the Moon’s surface does not support indigenous forms of life or the proliferation of terrestrial organisms brought to the Moon; (2) biological contamination of the lunar surface will not contaminate the lunar subsurface through the operation of natural processes on the Moon; and (3) any biological material identified in samples from the lunar surface or subsurface can be tested against terrestrial organisms to determine its source.

Finding 5: There is a lack of, and need for, studies to characterize the chemical composition, transport, and the level of contamination of volatiles that would be harmful to future investigations of prebiotic chemical evolution to be pursued at PSRs. This information is necessary to determine whether to establish planetary protection requirements for missions to these areas of the Moon, such as a requirement for reporting the inventory of propellants, combustion products, and potential off-gassing volatiles from spacecraft.

In arriving at the findings above, the committee concludes that a critical issue is the absence of formally defined and accepted, prioritized, science objectives. While development of such a strategy is not the proper role of this committee, it does lead to the committee’s final, overarching finding.

Finding 6: A clear articulation of prioritized science objectives to frame a strategy for exploration of the lunar PSRs does not exist and is required for an effective planetary protection policy for the Moon.

Suggested Citation:"Executive Summary." National Academies of Sciences, Engineering, and Medicine. 2020. Report Series: Committee on Planetary Protection: Planetary Protection for the Study of Lunar Volatiles. Washington, DC: The National Academies Press. doi: 10.17226/26029.
×
Page 1
Suggested Citation:"Executive Summary." National Academies of Sciences, Engineering, and Medicine. 2020. Report Series: Committee on Planetary Protection: Planetary Protection for the Study of Lunar Volatiles. Washington, DC: The National Academies Press. doi: 10.17226/26029.
×
Page 2
Next: 1 Introduction »
Report Series: Committee on Planetary Protection: Planetary Protection for the Study of Lunar Volatiles Get This Book
×
Buy Ebook | $14.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

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.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!