The Committee on Astrobiology and Planetary Sciences of the National Academies of Sciences, Engineering, and Medicine is tasked with monitoring the progress in implementation of the recommendations of the most recent planetary science decadal survey, Vision and Voyages for Planetary Science in the Decade 2013-2022. Planetary science decadal surveys evaluate the state of the field, identify the most important scientific questions and themes, and prioritize missions and activities for the decade in question based on scientific merit, technical feasibility, and anticipated cost. The need for careful monitoring is underscored by the fact that some of the decadal survey's recommendations are triggered at specific programmatic decision points. Options for the Fifth New Frontiers Announcement of Opportunity addresses one such decision point. For each of the following four New Frontiers targets: Ocean Worlds, Trojan Tour and Rendezvous, Io Observer and Lunar Geophysical, this report summarizes changes in scientific understanding or external factors since the release of Vision and Voyages or its midterm review and considers whether those changes have been sufficiently substantial to warrant reconsideration of the four targets for inclusion in the New Frontiers 5 announcement of opportunity, scheduled for release in early 2022.

This study discusses the publicly available studies of future flagship- and New Frontiers-class missions NASA initiated since the completion of Vision and Voyages. The report considers the priority areas as defined in Vision and Voyages where publicly available mission studies have not been undertaken; appropriate mechanisms by which mission-study gaps might be filled in the near- to mid-term future; and other activities that might be undertaken in the near- to mid-term future to optimize and/or expedite the work of the next planetary science decadal survey committee.

On December 11, 2017, President Donald Trump signed Space Policy Directive-1 (SPD-1). The new directive replaced original text in the National Space Policy of the United States of America and instructed the Administrator of the National Aeronautics and Space Administration (NASA) to "lead the return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations". In response to and in support of the vision expressed in SPD-1, the first report reviewed decadal and other community-guided lunar science priorities as context for NASA's current lunar plans and then presented and evaluated the actions being taken by NASA's Planetary Science Division (PSD) to support lunar science. At the request of NASA PSD, this second report explores plans for commercial partnerships, lunar infrastructure development, and related aspects of NASA's lunar science and exploration initiative.

On December 11, 2017, President Donald Trump signed Space Policy Directive-1 (SPD-1). The new directive replaced original text in the National Space Policy of the United States of America and instructed the Administrator of the National Aeronautics and Space Administration (NASA) to "lead the return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations". In response to and in support of the vision expressed in SPD-1, this report reviews decadal and other community-guided lunar science priorities as context for NASA's current lunar plans and then presents and evaluates the actions being taken by NASA's Planetary Science Division to support lunar science.

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.