i

Office of Technology, Policy, and Strategy 

Lunar Landing and 

Operations Policy 

Analysis 

Gabriel Swiney, Amanda Hernandez 

Reviewers: Jacob Bleacher, Ruthan Lewis, Gabriel Merrill, Zachary Pirtle, 

Emily Sylak-Glassman 

September 30, 2022 

Report ID 20220015973 

NASA Headquarters 

300 E Street SW 

Washington, DC 20024 

This report would not have been possible without the extensive 

cooperation of experts across NASA. The work of NASA’s CrossArtemis Site Selection Analysis team has been particularly valuable, 

and we have relied on experts across mission directorates, centers, 

and within NASA Headquarters for every section of this report. This 

effort underscores the reality that creating a safe, sustainable, and 

predictable presence on the Moon and beyond is a task for the entire 

agency. 
For more information on the NASA Office of Technology, Policy, and Strategy to view this and other 

reports visit https://www.nasa.gov/offices/otps/home/index.html

Executive Summary 

Lunar Landing and Operations Policy Analysis 

Purpose of the Study 

Just within the next four years, we expect to see at least 22 lunar surface missions. Half of these 

missions will occur in the Moon’s south polar region. Due to this upcoming proliferation of actors 

and activities at or near the lunar south pole, and due to the potential close proximity of 

operations, NASA and other operators will face challenges never faced before. 

NASA’s Deputy Administrator and Associate Administrator of the Science Mission Directorate (SMD) 

tasked the Office of Technology, Policy, and Strategy (OTPS) with answering two questions related 

to the Artemis campaign: (1) what technical and policy considerations should NASA take into 

account in the selection of lunar landing and operations sites, and (2) what technical and policy 

considerations should NASA take into account when implementing tools such as safety zones in 

order to protect these operations and U.S. interests? 

In addition to the challenges inherent in lunar operations, NASA subject-matter experts (SMEs) are 

concerned about certain challenges to NASA operations that may require policy solutions. The goal 

of this report is to provide options and recommendations to NASA leadership and program planners 

so that they can consider policy measures to respond to those challenges. This report also describes 

options for transparency, coordination, and implementation to increase the effectiveness of these 

measures. 

Key Findings

SMEs expressed particular concerns relating to seven specific activities: landings, surface 

operations, surface travel, radio-frequency interference, human heritage, areas with special 

characteristics, and unexpected activities. Each of these challenges is amenable to one or more 

policy measures that can reduce the risk to NASA operations (see Table 1 below). Implementation 

of these policy measures would require that policy considerations be taken into account in 

spacecraft and mission design, a considered effort to make our policy choices known publicly, and 

coordination amongst space actors (see Table 2 below). 

Not all challenges—and thus, not all policy responses to them—need be implemented immediately, 

simultaneously, or for every NASA activity. A gradual approach to implementing these measures is 

September 30, 2022 Report ID 20220015973 
ii

possible. NASA leadership will determine at which point, if ever, is a challenge significant enough to 

warrant action. 

Question 1: What technical and policy considerations should NASA take into account in 

the selection of lunar landing and operations sites? 

We identified seven major challenges to landing and operating at the lunar South Pole and provide 

the following policy tools (options and recommendations to address challenges) as additional points 

to consider for Artemis landing and operations sites. 

Table 1. Key challenges to lunar landing and surface operations and corresponding policy tools to mitigate each 

challenge. 

Challenge Overview Summarized Policy Tool 

Challenges Posed 

by Landings 

Landings will create plumesurface interactions (PSIs) that 

can damage assets—significant 

gaps in understanding their 

effects exist 

Increase priority of obtaining PSI measurements; 

identify distances from landing sites that will 

reduce danger from particles to tolerable levels; 

develop “gold standards” for PSI predictions with 

partner space agencies; work with partners to

develop landing and ascent infrastructure to 

mitigate dangers from particles 

Threats to and 

From Surface 

Operations 

Activities on the surface can 

cause damage to or interfere 

with surface assets and 

operations 

Begin implementation of the concept of safety

zones (envisioned in the Artemis Accords)—

incorporate into mission planning and design on a 

mission-by-mission basis; take additional steps to 

reduce the need for safety zones (e.g., landing 

infrastructure); respect similar tools used by nonsignatories to the Accords 

Challenges to 

Moving Across 

the Lunar Surface 

Technical constraints limit the 

ability to move between areas 

of interest—there is a need to 

ensure navigable pathways 

remain available for use 

Ensure our understanding of navigable pathways 

between sites of interest is robust; if there 

continues to be a need to protect these pathways,

identify them as “transit corridors” and ensure their 

protection; if fixed facilities must be placed on

these corridors, make their locations known and 

ensure they do not block mobile assets 

The Danger of 

Radio-Frequency 

Interference 

Surface operations could be 

subject to radio-frequency 

interference 

Continue to engage with the interagency and rely 

on the International Telecommunication Union 

(ITU)—specialized policy tools for lunar surface 

operations are not needed 
Threats to Areas 

with Special 

Characteristics 

Certain locations may warrant 

protection if operations may 

render them less useful 

Ensure freedom of access to areas conducive to 

operations, such as the Connecting Ridge; work 

with Artemis partners to support United Nations 

space resource efforts for sustainable in-situ 

resource utilization (ISRU) 

The Challenge of 

Unexpected 

Activities on the 

Surface 

Security-related concerns 

could interfere with surface 

operations 

Consider incorporating multi-purpose hardware 

(e.g., cameras, sensors) onto missions that can 

identify proximity operations from other actors 

The Need for 

Human Heritage 

Protection 

The U.S. may wish to preserve 

non-operational sites for their 

historic or cultural value 

Continue to implement the 2011 

Recommendations1 for Apollo and Surveyor sites; 

apply them to any new heritage sites; use restraint 

in identifying any new heritage sites; determine if 

other nations request human heritage protection;

look to terrestrial heritage protection to develop 

formal processes 

Question 2: What technical and policy considerations should NASA take into account 

when implementing tools such as safety zones in order to protect these operations and 

U.S. interests? 

When implementing tools to address challenges to landing and operating at the lunar South Pole, 

such as those mentioned in Table 1, we suggest the following as a means to increase their 

effectiveness, thus protecting operations and U.S. interests.

Table 2. Options for building transparency into next steps, coordinating when necessary, and implementing policy 

tools into mission planning.

Purpose Summarized Options to Supplement Policy Tools 

Transparency To address potential 

concerns and increase 

effectiveness of policy tools 

Build on the transparency section of the Artemis 

Accords by 1) meeting with signatories to discuss policy 

tools for upcoming missions and, 2) developing a public 

relations strategy along with multilateral engagement 

to explain rationale for policy tools 

Coordination To actively involve the 

space community before 

implementing policy tools, 

Work with the Department of State to ensure partners 

on joint missions share our views on responding to 

1

“NASA’s Recommendations to Space-Faring Entities: How to Protect and Preserve the Historic and Scientific Value 

of U.S. Government Lunar Artifacts,” July 2011: https://www.nasa.gov/pdf/617743main_NASAUSG_LUNAR_HISTORIC_SITES_RevA-508.pdf. 

iii
iv

especially when related to 

cooperative missions 

challenges; develop mechanisms for consultation and 

coordination to deconflict surface operations 

Implementation To put policy tools into 

practice by incorporating 

into mission plans 

For missions over which NASA has operational control, 

build policy tools into mission planning; for missions 

operated as a service, work with contracting 

companies to implement relevant policy tools 

Next Steps 

Existing data is limited, and substantial lunar surface operations have yet to occur. Each mission and 

location on the lunar surface present unique physical characteristics. Discussion of the options and 

implementation of relevant policy tools will need to be tailored to each mission and should evolve 

as knowledge accrues. 

Not all policy tools will need to be evaluated or adopted immediately; some may only become 

relevant as increasing numbers of missions go to the lunar South Pole. Likewise, increasing volumes 

of traffic to the lunar surface may require stricter implementation of certain tools; conversely, 

advances in technology and infrastructure could allow relaxation of those same measures. These 

policy tools should be revisited as necessary. As we gain experience, similar measures may be 

applied to missions to Mars and other celestial bodies. 

Key next steps to address challenges to landing and surface operations include: 1) working desired 

policy tools from Table 1 into current and upcoming mission plans, 2) building options for 

transparency, coordination, and implementation from Table 2 into desired policy tools, and 3) 

revisiting these policy tools as needed, and especially as we learn more from early lunar surface 

missions. 

Some of the options described in this report require technical information to be gathered and 

analyzed in light of the policy challenges identified here—that analytical and policy design work 

might be a useful early priority for NASA. As section 3.3 of this report describes, NASA may wish to 

begin developing technical criteria for landing standoff distances and safety zones now, for 

example, before they become operationally necessary, so that those measures are available when 

needed. Policymakers might consider beginning this sort of hybrid technical-policy design work 

now. 
Table of Contents 

Executive Summary ............................................................................................................. i

Purpose of the Study ...................................................................................................................... i

Key Findings................................................................................................................................... i

Question 1: What technical and policy considerations should NASA take into account in the selection of lunar 

landing and operations sites? ..............................................................................................................................ii

Question 2: What technical and policy considerations should NASA take into account when implementing 

tools such as safety zones in order to protect these operations and U.S. interests? .........................................iii

Next Steps ....................................................................................................................................iv

Table of Contents ............................................................................................................... v

Introduction ......................................................................................................................... 7

Part 1: Setting the Scene ................................................................................................... 9

1.1 Goals of Artemis .......................................................................................................................9

1.2 Anticipated Architecture.........................................................................................................10

1.3 Technical Constraints ..............................................................................................................11

1.4 Implications of Goals and Constraints .....................................................................................16

1.5 Current Status of Planning ......................................................................................................17

1.6 Prior Work .............................................................................................................................17

Part 2: Challenges and Tools ........................................................................................... 19

2.1 Challenges Posed by Landings ................................................................................................. 21

2.2 Threats to and from Surface Operations ..................................................................................28

2.3 Challenges to Moving Across the Lunar Surface .......................................................................35

2.4 The Danger of Radio-Frequency Interference ..........................................................................38

2.5 Threats to Areas with Special Characteristics ...........................................................................39

2.6 The Challenge of Unexpected Activities on the Surface............................................................41

2.7 The Need for Human Heritage Protection ................................................................................42

Part 3: Transparency, Coordination, and Implementation ............................................ 48

3.1 Transparency .........................................................................................................................49

v 
vi

3.2 Coordination ..........................................................................................................................52

3.3 Implementation .....................................................................................................................53

Part 4: Summary, Conclusions, and Next Steps ............................................................ 58

4.1 Summary of Findings, Options, and Recommendations ...........................................................58

Policy Tools to Address Challenges to South Polar Landing and Operations .....................................................58

Options to Supplement Policy Tools ..................................................................................................................61

4.2 Known Unknowns ..................................................................................................................62

4.3 Revisiting the Recommendations ............................................................................................63

4.4 Conclusion .............................................................................................................................63

Appendix A: Terms of Reference .................................................................................... 64

Background ................................................................................................................................. 64

Goals and Study Questions ...........................................................................................................65

Scope of Work and Proposed Approach ........................................................................................65

Intended Outcomes .....................................................................................................................66

Deliverables ................................................................................................................................. 67

Intended Distribution and Access ................................................................................................. 67

Appendix B: List of Those Consulted ............................................................................. 68

Phase I: Internal Discussions (NASA Lunar Program Leads/Points of Contact and SMEs) .................68

Phase II: External Discussions (Space Agencies) .............................................................................68

Phase III: External Reviews (Cross-Disciplinary Experts) ................................................................. 68

Appendix C: List of Near-Term Lunar Missions ............................................................. 69

Appendix D: Beyond this Project .................................................................................... 72

A Note Regarding Mars ................................................................................................................72

Equity and Ethics ..........................................................................................................................72

Appendix E: Acronyms .................................................................................................... 73
7 

Introduction 

The Artemis campaign comprises a range of exploration and science missions. Artemis is not a 

traditional NASA “program” in the sense of having unified leadership and funding. Rather, it is a 

broad articulation of a unified purpose across missions, funding lines, directorates, and 

partnerships. Led by NASA with extensive commercial and international partnerships, the Artemis 

Program “will establish a sustainable presence on the Moon to prepare for missions to Mars.”2 The 

Artemis campaign will include crewed operations to lunar orbit and the lunar surface as well as 

uncrewed robotic operations in these areas. Major NASA-led programs that are part of the Artemis 

campaign include Gateway, Human Landing System (HLS), Orion, Space Launch System (SLS), 

Commercial Lunar Payload Services (CLPS), Extravehicular Activity (EVA) and Human Surface 

Mobility (HSM) program, and a lunar base. Each of these programs involves commercial and 

international contributions. International partner-led operations may include the European Large 

Logistics Lander (EL3), pressurized and unpressurized rovers, additional robotic surface missions, 

and contributions to surface habitats.3,4,5,6 NASA and partners are also considering additional 

operations aimed at ensuring sustainability of operations, such as in-situ resource utilization (ISRU) 

and technical capabilities to support operations, including power, communications, and landing 

infrastructure. Taken together, these elements form the Artemis campaign—the most ambitious 

space exploration program ever undertaken by humanity. 

In light of these plans for Artemis, the Science Mission Directorate (SMD) and the Deputy 

Administrator tasked the Office of Technology, Policy, and Strategy (OTPS) with answering two 

related questions: (1) what technical and policy considerations should NASA take into account in 

the selection of lunar landing and operations sites and (2) what technical and policy considerations 

should NASA take into account when implementing tools such as safety zones in order to protect 

these operations and U.S. interests? This report aims to answer those questions.7

2

“Artemis Program,” NASA, last modified July 1, 2021, https://www.nasa.gov/artemisprogram. 

3

“Gateway International Partners,” Gateway, NASA, last modified December 2, 2021, 

https://www.nasa.gov/gateway/international-partners. 

4

“N° 30–2022: From the Earth to the Moon and on to Mars – ESA and NASA take decisions and plan for the 

future,” Press Release, European Space Agency, last modified June 15, 2022, 

https://www.esa.int/Newsroom/Press_Releases/From_the_Earth_to_the_Moon_and_on_to_Mars_ESA_and_NAS

A_take_decisions_and_plan_for_the_future. 

5

“NASA, Australia Sign Agreement to Add Rover to Future Moon Mission,” Moon to Mars, NASA, last modified 

October 12, 2021, https://www.nasa.gov/feature/nasa-australia-sign-agreement-to-add-rover-to-future-moonmission. 

6

“Joint Statement on Cooperation in Lunar Exploration,” Press Release, Japan Aerospace Exploration Agency, last 

modified September 24, 2019, https://global.jaxa.jp/press/2019/09/20190924a.html. 

7

 A list of all options and recommendations is excerpted in the Summary Chapter of this report. 
As described in the Terms of Reference (TOR), this project gathered information in three phases.8

First, OTPS conducted a series of meetings with NASA lunar program experts to develop a detailed 

baseline of what is possible and desirable from a programmatic perspective, as well as an 

understanding of what technical criteria should be used to implement policy tools. Those meetings 

are set out in Appendix B and the information gained is described in Part I of this report. Second, 

OTPS and the Office of International and Interagency Relations (OIIR) met with counterpart space 

agencies with whom NASA anticipates possible cooperation in lunar missions in order to seek their 

input on considerations relevant to the goals of the study; these conversations are also listed in 

Appendix B. After gathering this information, we created a set of draft options and 

recommendations and a draft report; we then shared this material with many of the internal 

experts we spoke to in Phase I to seek further comments. In the third and final phase, we shared 

the draft options and recommendations, and a draft report summary, with trusted outside experts 

(listed in Appendix B). The guidance provided by these experts has been considered in this 

document. 

The goal of this report is to provide options and recommendations to NASA leadership and program 

planners so that they can implement specific policy and related tools in Artemis Program missions. 

In Part 1 of the report, we set the scene, providing the context that gives rise to the need for policy 

options and recommendations. In Part 2, we describe the main challenges and hazards posed by 

landing and operating at the lunar South Pole. Each challenge has associated policy options and 

recommendations—this answers TOR Question 1. Part 3 describes the steps to take once policy 

tools move towards implementation—this answers TOR Question 2. Finally, Part 4 summarizes this 

study’s key takeaways. 

The options and recommendations contained in this report are intended to be flexible. As we 

discuss, not all options or recommendations need be considered or implemented immediately or 

for all operations, and implementation should adapt over time in light of new knowledge and 

should change in response to the realities of operations on the Moon. Because Artemis campaign 

missions have not yet begun, and because our knowledge of key technical and scientific factors is 

limited, these options and recommendations are inherently preliminary. Many of the operations 

described in this report as part of the Artemis campaign are in planning stages; this report attempts 

to describe considerations relevant to them all but draws heavily from current plans for early CLPS 

and initial HLS operations. 

8

 Appendix A. 

8
9

Part 1: Setting the Scene 

As described above, Phase I of this project was intended to develop a baseline understanding of the 

goals of Artemis lunar operations as well as the technical constraints that shape our ability to meet 

those goals. Understanding those goals and constraints is critical to designing policy tools for lunar 

operations. 

1.1 Goals of Artemis 

The recently released “Moon to Mars Objectives” process identified numerous objectives for 

NASA’s campaign to operate on the Moon and in cislunar space with an ultimate goal of human 

exploration of Mars.9,10,11 An extensive internal and external comment process is ongoing to refine 

these objectives. The specific phrasing and organization of these objectives are not critical to this 

report; the draft objectives provide sufficient clarity to identify policy and operational issues that 

might result from lunar operations, particularly when combined with existing programs and 

architectures (as described below). 

The first category of objectives relevant to lunar operations is science and exploration. Human and 

robotic exploration of the lunar surface aims to answer many questions about the nature of the 

Moon and the history of the solar system. Many of these objectives focus on investigating the 

nature of volatiles and other potential resources on the lunar surface.12 These resources, 

particularly frozen volatiles, are most likely to be found in permanently shadowed regions (PSRs), 

which principally exist around the lunar poles.13 

Lunar operations also have technology objectives. The Artemis campaign aims to develop, test, and 

deploy technologies that will allow expanded human and robotic exploration of the Moon and, 

ultimately, Mars. These technologies include power generation and transmission, communications 

networks, landing infrastructure, automated exploration capabilities, and pressurized habitats.14

Finally, an overarching objective of lunar operations is to develop a sustainable presence on the 

lunar surface. “Sustainability” is a broad concept: it encompasses the ability to operate an ongoing 

campaign of interrelated missions rather than a series of “one off” missions. Inherent in that 

9

 Cislunar space is generally considered to be the area defined by the orbit of the Moon around Earth, including 

lunar orbits and Earth-Moon Lagrange points. 

10 “Update: NASA Seeks Comments on Moon to Mars Objectives by June 3,” Moon to Mars, NASA, last updated 

June 8, 2022, https://www.nasa.gov/press-release/update-nasa-seeks-comments-on-moon-to-mars-objectives-byjune-3.

11 “Moon to Mars Objectives,” NASA, accessed June 17, 2022, 

https://www.nasa.gov/sites/default/files/atoms/files/moon-to-mars-objectives-.pdf. 

12 See Moon to Mars Objectives: ES-5, LPS-2.

13 J. Flahaut et al., “Regions of interest (ROI) for future exploration missions to the lunar South Pole,“ Planetary and 

Space Science 180 (Jan. 2020): https://doi.org/10.1016/j.pss.2019.104750. 

14 See Moon to Mars Objectives: L1-4.
10

concept is the idea of an evolving, increasing ability to engage in longer, more complex operations 

over time. Sustainability also implies the need to avoid taking actions that limit our ability to 

undertake operations in the future (e.g., by not blocking access to scientifically interesting locations 

with dead hardware), and to develop capabilities to reduce the financial and material cost of 

ongoing activities. This also relates to ethics and equity considerations, mentioned in Appendix D, 

which OTPS has ongoing work on.

Sustainability brings together the scientific and technology objectives of the Artemis program. For 

example, one step towards sustainable operations could be to couple newfound scientific 

knowledge about the presence of water ice with developments in automated robotic operations to 

enable ISRU. Sustainable operations then enable future scientific discoveries and technological 

advances, including by lowering costs, which in turn enable even more advances in sustainability. 

The aim is a virtuous cycle of increasing discovery and capabilities. 

1.2 Anticipated Architecture 

To pursue the objectives identified above, NASA and partners have developed a notional 

architecture for lunar operations. This notional architecture continues to evolve and contains many 

elements, most of which remain to be fully defined.15

Near-term missions are the most well-defined aspect of these plans. The CLPS initiative, operated 

by SMD, contracts with commercial companies to deliver science and technology payloads to the 

lunar surface. Currently consisting of fourteen vendors and seven awarded task orders,16 CLPS will 

continue to add additional landings and increased capabilities (e.g., mobility, survive the night, 

sample return, etc.) as the initiative develops.17 CLPS deliveries vary in size, cost, and destination, 

with approximately half of the currently planned deliveries targeting the south polar region. 

Although early CLPS deliveries and their payloads will for the most part only operate for a period of 

days or a few weeks on the Moon, they will provide scientific and other data necessary to enable 

future crewed and uncrewed missions. 

Aside from CLPS, the most well-defined aspect of the Artemis architecture is the Human Landing 

System (HLS). As part of the NextSTEP public-private partnership model, NASA selected SpaceX’s 

Starship to provide crewed landing in the vicinity of the lunar South Pole for the Artemis III 

mission.18 Specific landing sites have yet to be determined. Some site down-selection may occur as 

the result of information gained from CLPS, an uncrewed demonstration prior to Artemis III, and 

15 We note that Gateway is a well-defined and critical component of the Artemis architecture. Because this report 

focuses primarily on policy issues relating to surface operations, we do not focus on Gateway. 

16 As of the time of drafting (July 2022). Please see Appendix C for more detail on CLPS missions. 

17 “Commercial Lunar Payload Services Overview,” Commercial Lunar Payload Services, NASA, last updated July 21, 

2022, https://www.nasa.gov/content/commercial-lunar-payload-services-overview.

18 “NextSTEP H: Human Landing System,” NextSTEP, NASA, accessed June 17, 2022,

https://www.nasa.gov/nextstep/humanlander2. 
11

other sources, but a final landing site decision will depend on the specific launch date. Artemis III is 

expected to spend approximately 6 days on the lunar surface.19

In March 2022, NASA requested SpaceX “to transform the company’s proposed human landing 

system into a spacecraft that meets the agency’s requirements for recurring services for a second 

demonstration mission.”

Plans for crewed landings on the Moon beyond Artemis III have not yet been finalized. In addition 

to Starship, Appendix P of the HLS program is currently in the process of selecting additional landing 

system providers for “Sustaining Lunar Development.” These providers will provide crewed 

transportation to the lunar surface after Artemis III (and a potential second demonstration mission). 

The spacecraft, timing, and destinations have not been decided, though the draft solicitation in 

Appendix P calls in part for “lunar surface landing near the South Pole, lunar surface extra-vehicular 

activity (EVA), [and] return of crew and materials from the surface and transfer from HLS.” 

Appendix P is intended to culminate in a crewed demonstration mission, with anticipated contract 

performance from 2023-2028. 

Additional elements of the Artemis architecture remain in planning stages. For example, NASA is 

considering communications and power infrastructure to support sustained operations20 and 

extensive planning has gone into developing “lunar base” concepts, though these ideas have not 

been finalized or otherwise approved.21,22

Finally, certain architecture elements exist only in study form. Safety features such as protection 

berms and waste disposal trenches, and structures such as prepared landing pads, remain key 

elements of architecture planning (and as will be discussed, of key importance to policy 

considerations), but have not yet made it from planning studies to programmatic documentation. 

1.3 Technical Constraints 

The lunar surface is not a hospitable environment. In addition to inherent difficulties of operating 

anywhere on the Moon (radiation, vacuum, dust), several technical constraints are particularly 

relevant to operations in the vicinity of the lunar South Pole. These constraints limit what 

operations are possible and where those possibilities exist. 

19 “NASA‘s Lunar Exploration Program Overview,” Artemis Plan, NASA, last modified September 2020, 

https://www.nasa.gov/sites/default/files/atoms/files/artemis_plan-20200921.pdf. 

20 “Moon to Mars Objectives,” NASA, accessed June 17, 2022, 

https://www.nasa.gov/sites/default/files/atoms/files/moon-to-mars-objectives-.pdf. 

21 “NASA‘s Lunar Exploration Program Overview,” Artemis Plan, NASA, last modified September 2020, 

https://www.nasa.gov/sites/default/files/atoms/files/artemis_plan-20200921.pdf. 

22 “NASA’s Plan for Sustained Lunar Exploration and Development,” NASA, accessed June 17, 2020, 

https://www.nasa.gov/sites/default/files/atoms/files/a_sustained_lunar_presence_nspc_report4220final.pdf. 
12

The first—and arguably most important—constraint is the availability of sunlight. Access to sunlight 

provides two benefits: power and thermal control. These benefits are interrelated: because of the 

extreme cold of the lunar night, heating systems will be needed for crewed and robotic operations 

if they are to survive periods of darkness. Early CLPS deliveries, for example, are expected to survive 

only one lunar day, permanently ending operations when they experience the extreme cold and 

loss of power of a lunar night.23 Crewed operations are also planned to take place only during 

periods of sunlight.24

Because polar operations are, by definition, at high latitudes, sunlight approaches these areas from 

a shallow angle: shadows are long, and the sun never rises more than 1.5 degrees above the 

horizon.25 At the same time, a handful of areas located on peaks and crater rims receive far more 

sunlight, on a yearly basis, than is available anywhere else on the Moon.26,27,28 This low angle of 

insolation is also what gives rise to the PSRs described above. 

The result of this solar environment is that the south polar region is one of large, constantly shifting 

shadows, interspersed with arcs, points, and a few regions of direct sunlight. These features change 

over the lunar day and year in a way that it is predictable indefinitely in advance. These alwaysmoving sunlit areas are of critical importance to missions that rely on insolation for power and 

heating, as is the case for essentially all currently planned missions. 

23 “Commercial Lunar Payload Services (CLPS) Technical Integration,” NASA, last modified January 14, 2021, 

https://science.nasa.gov/science-pink/s3fs-public/atoms/files/CLPS-Technical-Integration-Schonfeld.pdf. 

24 “Artemis Lighting Considerations Overview,” NASA-STD-3001 Technical Brief, NASA, last modified January 25, 

2022, 

https://www.nasa.gov/sites/default/files/atoms/files/artemis_lighting_considerations_overview_technical_brief_

ochmo.pdf. 

25 P. Glaser et al., “Illumination conditions at the lunar south pole using high resolution Digital Terrain Models from 

LOLA,” Icarus 243 (Nov. 2014): https://doi.org/10.1016/j.icarus.2014.08.013. 

26 Despite popular belief, there are no “peaks of eternal light” on the Moon. Every site identified is in shadow at 

some portion of the lunar cycle. D. Ben J. Bussey, Paul D. Spudis, Mark S. Robinson, “Illumination conditions at the 

lunar south pole,” Geophysical Research Letters 26, no. 9 (May 1999): 

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/1999GL900213. 

27 P. Glaser et al., “Illumination conditions at the lunar poles: Implications for future exploration,” Planetary and 

Space Science 162 (Nov. 2018): https://doi.org/10.1016/j.pss.2017.07.006. 

28 D. Ben J. Bussey, Paul D. Spudis, Mark S. Robinson, “Illumination conditions at the lunar south pole,” Geophysical 

Research Letters 26, no. 9 (May 1999): https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/1999GL900213. 
13

Figure 1. Average Illumination of the South Polar Region (Image Credit: CASSA) 

Figure 2. Representative Snapshot of Illumination at the South Pole (Image Credit: NASA's Scientific Visualization Studio) 

Sunlight is not the only way to provide power and thermal control for lunar operations. Mission 

architectures that involve other power sources, such as fuel cells for short durations and nuclear 

power for longer durations, would reduce or eliminate the need for sunlight. Hybrid solutions might 

also be possible, such as fixed solar or nuclear-powered “charging stations.” However, none of 
14

these alternative power sources have yet been incorporated into definite mission plans. The need 

for sunlight therefore remains a driving constraint for anticipated human and robotic lunar 

operations. 

Another critical constraint is terrain. The lunar surface is diverse, but the south polar region is 

characterized by heavily disrupted terrain, with several large craters dominating the area. Peaks, 

valleys, boulders, and rocks of all sizes are common.29,30,31 This dramatic landscape imposes 

technical challenges. 

Figure 3. Topographic Relief of the Lunar South Pole and Areas of Interest (Image Credit: CASSA). 90°S is marked by the star at 

Shackleton Crater. 

The first constraint imposed by the landscape is the need to identify relatively flat and uncluttered 

areas that can function as landing sites. CLPS contractual documentation requires those robotic 

craft to land within a landing ellipse 100m in diameter, while HLS contracts require a landing radius 

of 100m for HLS A and 50m for Option B and SLD.32 There is a finite number of such locations in the 

29 A.C. Cook et al., “Lunar polar topography derived from Clementine stereoimages,” Journal of Geophysical 

Research 105, no. E5 (May 2000): https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/1999JE001083. 

30 V.T. Bickel, D.A. Kring, “Lunar south pole boulders and boulder tracks: Implications for crew and rover traverses,” 

Icarus 348 (Sept. 2020): https://doi.org/10.1016/j.icarus.2020.113850. 

31 H. Araki, et al., “Lunar Global Shape and Polar Topography Derived from Kaguya-LALT Laser Altimetry,” Science 

323 (Feb. 2009): https://doi.org/10.1126/science.1164146. 

32 G. Chavers, L. Watson-Morgan, M. Smith, N. Suzuki and T. Polsgrove, "NASA's Human Landing System: The 

Strategy for the 2024 Mission and Future Sustainability," 2020 IEEE Aerospace Conference (2020): 

10.1109/AERO47225.2020.9172599, and https://sam.gov/opp/2d5b3e1f38bd4035a06b64b4704e3455/view. 
15

polar region that are free enough of obstructions to allow safe landings, though the specific number 

of those locations remains to be determined. 

The second constraint imposed by the landscape involves moving from one location to another. 

Crewed and robotic craft will need to move, for example, from a landing site to an area of scientific 

interest, or between areas of interest. Although a few robotic craft may be able to “hop” between 

sites, most mobile assets will be rovers, and crewed activities will be similarly ground-bound. 

Transit between sites is not trivial: although the straight-line distances involved are not large, 

crewed and robotic rovers must avoid large obstructions, dangerous slopes, and similar hazards. 

Finally, the nature of lunar terrain is directly linked to the availability of sunlight. Depending on their 

orientation, peaks, valleys, and other topologies experience more, or less, sunlight than other areas 

of the lunar surface. 

As described in the Goals of Artemis section above, lunar volatiles—particularly water ice—are key 

to Artemis operations. Investigating the existence and composition of frozen volatiles is not only a 

science goal; accessing and using these resources to support future exploration through ISRU 

increases the sustainability and lowers the cost of operations. Frozen volatiles are most likely to 

exist in PSRs, which themselves are generally found in the bottom of deep craters located near the 

poles. Limited sorties may go elsewhere on the lunar surface, but this need for volatiles places an 

additional constraint on operations: the need to stay close to PSRs or other sources of accessible 

volatiles. 

The final general constraint has to do with communications. Early mission plans require nearcontinuous radio communications with crewed activities.33 At present, this is only possible with 

direct line-of-sight between Earth and certain locations at the lunar South Pole at certain times. 

These locations change throughout the Moon’s sidereal month (27.3 days).34 Orbital 

communication relays would resolve this constraint and are anticipated to be available after 

Artemis III. Until those assets are in place, the need to maintain direct line-of-sight with crewed 

operations remains. 

Table 3. Summary of major technical constraints related to south polar operations. 

Technical Constraint Primary Benefit South Polar Mission Impact 

Availability of 

sunlight 

Power, thermal control Missions relying on solar energy (all 

currently planned missions) 

33 “NASA‘s Lunar Exploration Program Overview,” Artemis Plan, NASA, last modified September 2020, 

https://www.nasa.gov/sites/default/files/atoms/files/artemis_plan-20200921.pdf. 

34 C. Immer, J. Lane, P. Metzger, S. Clements, “Apollo Video Photogrammetry Estimation of Plume Impingement 

Effects,” Earth and Space 2008 (Apr. 2012): https://doi.org/10.1061/40988(323)1. 
16

Terrain Safe landings, transits between 

sites, access to volatiles 

All missions 

Direct line-of-sight 

with Earth 

Communications with crewed 

operations 

Artemis III 

1.4 Implications of Goals and Constraints 

Taken together, the goals and constraints relevant to lunar operations shape what is possible for 

mission planners. Each factor described in this section of our report has the effect of limiting where 

operations can take place, how long they can continue, and what mission objectives are realistically 

possible. The result is a series of filters, with each factor placing further limits on operations. 

The net result of this filtering process is that near- and medium-term activities on the Moon will 

likely focus in a relatively small area. For example, only a small number of regions (centered around 

the lunar South Pole) contain PSRs that are likely to contain accessible volatiles. Within those 

regions, only a subset of sites has physical characteristics that are conducive to operations (e.g., by 

avoiding long periods of shadow and, for early missions, having direct radio line-of-sight to Earth). 

Access to these sites is a further constraint due to the need for relatively flat areas for landings 

and/or the need for sunlit corridors for surface travel. 

The need for sunlight and for navigable terrain are highly interrelated. When these two constraints 

are combined, the result is very few “transit corridors” between areas of interest such as the rim of 

the Shackleton and de Gerlache craters. Some sections of these transit corridors are very narrow. If 

access to these particularly narrow sections were lost, it could create challenges for site 

accessibility. 

NASA has developed an agency-wide process for taking these factors into account in mission 

planning. The Cross-Artemis Site Selection Analysis (CASSA) team brings together experts from 

NASA’s Science Mission Directorate (SMD), Exploration Systems Development Mission Directorate 

(ESDMD), Space Technology Mission Directorate (STMD), and relevant centers to coordinate 

planning across human and robotic missions. The CASSA team also consists of an engagement 

strategy team and has started looking to external communities in for input on site selection for 

Artemis III.35 Although CASSA’s work is ongoing, current plans suggest that lunar surface missions 

will focus on fewer than ten sites in the south polar region, all in the vicinity of the Shackleton, de 

Gerlache, Shoemaker, and Slater craters. These craters are contained within an area about 35km 

wide by 70km long. 

35

“NASA Identifies Candidate Regions for Landing Next Americans on Moon,” NASA, last modified August 19, 2022, 

https://www.nasa.gov/press-release/nasa-identifies-candidate-regions-for-landing-next-americans-on-moon. 
17

Another key geographic feature is the “Connecting Ridge,” a high elevation area between the de 

Gerlache and Shackleton craters.36

Although some Artemis missions are planned for non-polar areas of the Moon (including the first 

and several other CLPS deliveries), the majority of human and robotic missions will target the areas 

identified in Figure 3. This density of operations located in a small area is the most significant factor 

driving the policy recommendations of this report. 

1.5 Current Status of Planning 

We recognize that mission planning is ongoing. Early missions—especially the first few CLPS 

deliveries and the first crewed surface landing of Artemis III—have relatively well-defined plans, 

targets, and architectures. Beyond this first group of missions, plans and architectures still need to 

be decided. Regardless of the reasons, policymakers should be aware that this lack of clarity makes 

it difficult to provide specific policy options and recommendations for these notional missions.37 For 

example, NASA has publicly supported the development of a “base” at the lunar South Pole to 

support crewed operations, but the nature of this base—whether it will be fixed or mobile, its size, 

whether it has nuclear or solar power, etc.—remains undecided. The answers to those questions 

are of critical importance to developing policy options and recommendations. This report provides 

as much guidance as possible given existing levels of uncertainty, but policy recommendations will 

need to be refined and tailored as mission plans and architectures solidify. 

1.6 Prior Work 

This report is not the first time NASA has considered the policy implications and operational needs 

of lunar missions. In 2011, NASA released “NASA’s Recommendations to Space-Faring Entities: How 

to Protect and Preserve the Historic and Scientific Value of U.S. Government Lunar Artifacts.”38 The 

2011 Recommendations were intended to provide guidance to commercial and other actors that 

might operate near historic NASA lunar sites: Apollo and Surveyor. This work considered some of 

the same considerations relevant to our current work, so we took the 2011 Recommendations into 

account in this report. Because the 2011 Recommendations are the only current, public, detailed 

36 CASSA began its work looking at approximately 230 sites; the plan is to down-select to 10 sites in 2023, then 

down-select to 3-5 sites by 2024. 

37 Policy-relevant decisions will be made at several levels of NASA: some are likely to be made at the directorate 

level, while others may fall to the A-Suite. This report is intended to provide guidance to all those levels of 

decision-making. 

38 Human Exploration and Operations Mission Directorate, Strategic Analysis and Integration Division, NASA HQ, 

“NASA’s Recommendations to Space-Faring Entities: How to Protect and Preserve the Historic and Scientific Value 

of U.S. Government Lunar Artifacts,” July 2011: https://www.nasa.gov/pdf/617743main_NASAUSG_LUNAR_HISTORIC_SITES_RevA-508.pdf. 
18

official recommendations from NASA relating to lunar operations, it is important to understand 

what they say and why before making our own recommendations. 

The 2011 Recommendations are precisely what they say in the title: a set of technical 

recommendations for measures that actors could take to avoid damage to historic spacecraft sites, 

equipment, and artifacts such as footprints and flags.39 The 2011 Recommendations are just that—

recommendations—though the measures set out therein have been required to be included in 

NASA contracts and agreements since 2020.40 

Because the 2011 Recommendations focus only on protecting heritage sites, they do not address all 

of the issues raised by Artemis campaign operations. However, the 2011 Recommendations did 

take into account concerns such as the impact of propulsive landings on the Moon to other 

hardware. Therefore, they provide a useful starting point for many of the recommendations and 

considerations below. 

39 The 2011 Recommendations request space-faring entities to: 

Refrain from landing or overflying (including the possibility of an instantaneous impact) within a “descent/landing 

boundary” of 2km around Apollo landers. This radius is based on analysis of Apollo footage, which suggests that 

the most dangerous particles ejected by plume-surface interactions (PSIs), between 1 and 10cm in diameter, could 

have traveled up to 1.5km. 

Refrain from landing or overflying (including the possibility of an instantaneous impact) within a 

descent/landing boundary of 0.5km around impact sites (e.g., Ranger, LCROSS, S-IVB). This radius is reduced 

from that accorded Apollo landers due to the lower scientific and cultural value of impact sites. 

Refrain from surfaces approaches to the Apollo 11 and 17 sites within 75m and 225m, respectively. These radii 

are sized to encompass all evidence of human activity. 

Refrain from surface approaches to the Apollo 12 and 14-16 sites within much smaller radii around each 

significant piece of equipment (e.g. 3m from descent stages, 1m from lunar rovers, etc.). 

Refrain from movement at a speed that could eject material forward when within 10m of laser rangingretroreflectors, and from approaching the LRRRs within 1m. 

Additional recommendations cover topics such as entry into Surveyor impact craters, avoidance of contamination, 

and disposal of new objects in heritage sites. 

40 See the discussion of heritage protection below. 
19

Part 2: Challenges and Tools 

TOR Question 1: What technical and policy considerations should NASA take into account in the 

selection of lunar landing and operations sites? 

The background discussed above provides the basis to answer the first TOR question posed by SMD 

and the Office of the Administrator. After speaking with SMEs, we identified seven main challenges 

or hazards to landing and operating at the lunar South Pole. This portion of the report is organized 

by each challenge and contains policy options and recommendations that can be considered to 

address each of them. These options and recommendations are summarized in Table 4 below as 

“policy tools” and can also be found in the Summary chapter. 

To exemplify how this section is broken out, many experts pointed out that propulsive landings on 

the surface of the Moon can pose hazards to other operations; we therefore have a set of policy 

tools (options and recommendations) on “Challenges Posed by Landings.” SMEs also identified the 

need to protect surface operations from interference, to preserve the ability to move around the 

lunar surface, and to respond to security challenges posed by potentially hostile actors, along with 

other concerns. For each challenge or hazard, we provide one or more policy tools to mitigate that 

concern. Just as scientific instruments are tools to answer scientific questions, these are the policy 

tools in NASA’s toolkit to respond to the challenges and hazards posed by lunar operations.

Although these tools are described separately, they could—and sometimes should—be deployed in 

conjunction or in sequence with each other for the same mission, depending on the nature of 

specific operations and the hazards they face or create.41

In addition to describing how these policy tools could be designed and implemented, this section of 

the report examines potential downsides and risks. 

The following table summarizes the challenges and policy tools to follow. 

Table 4. Key challenges and the corresponding policy tool to mitigate each challenge. 

Challenge to 

Landings and 

Operations 

Overview Policy Tool (See Summary Chapter for Full 

List) 

Challenges Posed 

by Landings 

Landings will create 

plume-surface 

interactions (PSIs) that 

Increase priority of obtaining PSI 

measurements; identify distances from 

landing sites that will reduce danger from 

41 For example, determining a safe distance from other actors to land a rover, then by implementing a safety zone 

around that rover while it is working, and then by creating a heritage protection area around that rover at end of 

life. 
20

can damage assets—

significant gaps in 

understanding their 

effects exist 

particles to tolerable levels; develop “gold 

standards” for PSI predictions with partner 

space agencies; work with partners to

develop landing and ascent infrastructure to 

mitigate dangers from particles 

Threats to and 

From Surface 

Operations 

Activities on the surface 

can cause damage to or 

interfere with surface 

assets and operations 

Begin implementation of the concept of 

safety zones (envisioned in the Artemis 

Accords)—incorporate into mission planning 

and design on a mission-by-mission basis; 

take additional steps to reduce the need for 

safety zones (e.g., landing infrastructure); 

respect similar tools used by non-signatories 

to the Accords 

Challenges to 

Moving Across the 

Lunar Surface 

Previously mentioned 

technical constraints limit 

the ability to move 

between areas of 

interest—there is a need 

to ensure navigable 

pathways remain 

available for use 

Ensure our understanding of navigable 

pathways between sites of interest is robust; 

if there continues to be a need to protect 

these pathways, identify them as “transit 

corridors” and ensure their protection; if 

fixed facilities must be placed on these 

corridors, make their locations known and 

ensure they do not block mobile assets 

The Danger of 

Radio-Frequency 

Interference 

Surface operations could 

be subject to radiofrequency interference 

Continue to engage with the interagency and 

rely on the International Telecommunication 

Union (ITU)—specialized policy tools for 

lunar surface operations are not needed 

Threats to Areas 

with Special 

Characteristics 

Certain locations may 

warrant protection if 

operations may render 

them less useful 

Ensure freedom of access to areas conducive 

to operations, such as the Connecting Ridge; 

work with Artemis partners to support 

United Nations space resource efforts for 

sustainable ISRU 

The Challenge of 

Unexpected 

Activities on the 

Surface 

Security-related concerns 

could interfere with 

surface operations 

Consider incorporating multi-purpose 

hardware (e.g., cameras, sensors) onto 

missions that can identify proximity 

operations from other actors 
21

The Need for Human 

Heritage Protection

The U.S. may wish to 

preserve non-operational 

sites for their historic or 

cultural value 

Continue to implement the 2011 

Recommendations to Spacefaring Entities for 

Apollo and Surveyor sites; use restraint in 

identifying if any upcoming sites need 

protection; determine if other nations 

request human heritage protection; look to 

terrestrial heritage protection to apply 

learnings 

2.1 Challenges Posed by Landings 

Selection of landing sites is driven primarily by operational needs and mission goals. As described in 

Part I, planners for CLPS, HLS, and other missions will engage in a multi-factor analysis to determine 

appropriate landing sites, taking into account features such as the availability of sunlight, local 

terrain, access to other surface assets, proximity of scientifically interesting destinations, and other 

factors. However, SMEs have also made clear that decisions about where and how to land on the 

surface of the Moon can pose challenges and hazards to other activities; we discuss how to respond 

to those challenges here. 

Landings on the Moon will create “plume-surface interactions” (PSIs): dust, rocks, and other surface 

material will be ejected from landing areas by the force of landers’ engines. This ejected material 

can pose a hazard to other objects in the vicinity of the landing zone. As a result, planners should 

take this danger into account when selecting landing sites. Landers themselves can also damage 

surface assets or resources by plume impingement coming directly from the lander. Characterizing 

this hazard may involve obtaining information from CLPS vendors. Since we will learn more about 

this as more missions occur, this report will focus on dangers caused by PSIs. 

While much has been learned about the physics of PSIs over the last few decades, significant gaps in 

knowledge still exist and can only be filled by taking measurements during the landing of spacecraft. 

The only flight data currently available derives from analysis of footage from Apollo missions and 

basic analysis of the Chang’e-3 landing. As mentioned elsewhere in this report, those analyses 

suggests that in the case of Apollo, particles between 1 and 10cm in diameter ejected by PSIs could 

have traveled up to 1.5km from the landing sites.42 Laboratory experiments, field experiments, 

remote sensing measurements, and computer models provide some insight into the PSIs that CLPS, 

HLS, and other Artemis operations might experience, but those predictions have not yet been 

42 Human Exploration and Operations Mission Directorate, Strategic Analysis and Integration Division, NASA HQ, 

“NASA’s Recommendations to Space-Faring Entities: How to Protect and Preserve the Historic and Scientific Value 

of U.S. Government Lunar Artifacts,” July 2011: https://www.nasa.gov/pdf/617743main_NASAUSG_LUNAR_HISTORIC_SITES_RevA-508.pdf. 
22

verified by experience. In the meantime, NASA investigators and leading SMEs continue to work to 

refine models.43

Figure 4. Current State of Knowledge Regarding PSIs44

Current predictions and Apollo data suggest that PSIs can eject surface debris at speeds up to 

2km/s. Landings have the potential to transport material across the entire surface of the Moon and 

even into open space.45 Substantial uncertainty exists, with different studies disagreeing about 

velocities of ejected particles by as much as 900m/s.46 Fortunately, most debris—particularly more 

massive particles—are not likely to travel as far.47 Larger rocket plumes, and ones from engines 

closer to the lunar surface, will eject more particles at higher velocities, so the design, 

configuration, and placement of engines all factor into the scale of PSI effects. 

43 As does the UK Space Agency. Their Office of the Chief Engineer is funding two studies at British universities to 

conduct laboratory experiments and build computer models of PSIs. 

44 Michelle Munk, “Plume Surface Interaction: Surface Excavation and Construction Impacts,” Surface Construction 

and Excavation Workshop, NASA, last modified August 20, 2021, 

https://ntrs.nasa.gov/api/citations/20210021530/downloads/LSIC_E%26C_Munk.pptx.pdf. 

45 M. M. Wittal, et al., “The Behavior of High-Velocity Dust Generated by Lander Plumes in the Lunar Environment,” 

AAS 20-511 (June 2020): https://ntrs.nasa.gov/citations/20205003590. 

46 D. Fontes, J. Mantovani, P. Metzger, “Numerical estimations of lunar regolith trajectories and damage potential 

due to rocket plumes,” Acta Astronautica 195 (June 2020): https://doi.org/10.1016/j.actaastro.2022.02.016. 

47 K. J. Berger, A. Anand, P. T. Metzger, C. M. Hrenya, “Role of collisions in erosion of regolith during a lunar 

landing,” Physics Rev. E. 87 (Feb. 2013): https://link.aps.org/doi/10.1103/PhysRevE.87.022205. 
23

Figure 5. Plots displaying the “seemingly random” location and distribution of dust as a function of velocity relative to landing 

sites.48

The most direct way of obtaining PSI data is to have dedicated instrumentation, cameras, videos, or 

sensors for surface missions, providing quantifiable information in a variety of environments. 

Where missions, especially those in progress, cannot have dedicated hardware for PSI 

measurements, obtaining data indirectly may be possible. Indirect means can include data buys for 

lander, mission, or non-NASA payload data. Once lunar operations begin, additional data will 

become available for better understanding of PSIs in a variety of lunar terrains. A NASA PSI project 

plans to include the Stereo Cameras for Lunar Plume-Surface Studies (SCALPSS) instrument on two 

early CLPS landers; this instrument has been designed to gather the data needed to refine PSI 

models.49 Another instrument that is funded through NASA’s Lunar Surface Instruments and 

Technology Payloads (LSITP) program, Heimdall, will fly on a third CLPS delivery and take dedicated 

PSI measurements during descent, as well as image the surface after landing to understand physical 

changes in the regolith properties beneath the spacecraft.50 Additional data should also become 

available by observing the effects of HLS landings. These types of imaging and descent data are 

imperative in helping close gaps in our current knowledge of PSI. 

We recommend that missions increase the priority of obtaining PSI measurements when possible. 

Mission planners should look for opportunities for dedicated PSI measurements spanning more 

missions or obtain data by indirect means if that is not possible. Data regarding PSIs should be 

shared publicly, consistent with longstanding NASA practice. It should be noted that these two 

48 M. M. Wittal, et al., “The Behavior of High-Velocity Dust Generated by Lander Plumes in the Lunar Environment,” 

AAS 20-511 (June 2020): https://ntrs.nasa.gov/citations/20205003590. 

49 “Tiny NASA Cameras to Watch Commercial Lander form Craters on Moon,” Moon to Mars, NASA, last updated 

May 19, 2021, https://www.nasa.gov/feature/langley/tiny-nasa-cameras-to-watch-commercial-lander-formcraters-on-moon. 

50 R. A. Yingst, et al., “THE HEIMDALL CAMERA SYSTEM: TURNING EYES ON THE MOON,” 51st Lunar and Planetary 

Science Conference (2020): https://www.hou.usra.edu/meetings/lpsc2020/pdf/1439.pdf. 
24

recommendations are congruent with the key recommendation from SMEs on understanding and 

mitigating plume effects.51 Adding capabilities of this sort would entail additional short-term cost 

compared to current plans, but would better inform how to protect hardware, especially in regions 

where many operations will occur; this could therefore reduce risks and, ultimately, costs. 

Figure 6. Anticipated Schedule of NASA's PSI Project52

Because of the substantial gaps in knowledge about PSIs, specific recommendations for lunar 

landings are difficult to provide. One fact appears certain: it is difficult to entirely eliminate the 

danger posed by plume-ejected debris to other activities that might be occurring on the lunar 

surface. “The hazard posed by that debris is a function of lander mass and distance from the landing 

site,” but because debris can travel around the entire body of the Moon, there is no distance that 

can entirely avoid the possibility of any impacts.53 Secondary impacts, and thus secondary ejecta, 

mean that even geographic features such as mountains, craters, and berms will not provide 

absolute protection. A paper by prominent experts summarizes the situation: 

Thus, for an exposed lunar base occupying 1 km2, the likelihood of sustaining an 

impact from a landing particle generated by 10 t lander may be described by the 

51 Ryan Watkins, et al., “Understanding and Mitigating Plume Effects During Powered Descents on the Moon and 

Mars,” Bulletin of the AAS 53 (May 2021): https://doi.org/10.3847/25c2cfeb.f9243994. 

52 Michelle Munk, “Plume Surface Interaction: Surface Excavation and Construction Impacts,” Surface Construction 

and Excavation Workshop, NASA, last modified August 20, 2021, 

https://ntrs.nasa.gov/api/citations/20210021530/downloads/LSIC_E%26C_Munk.pptx.pdf. 

53 D. Fontes, J. Mantovani, P. Metzger, “Numerical estimations of lunar regolith trajectories and damage potential 

due to rocket plumes,” Acta Astronautica 195 (June 2020): https://doi.org/10.1016/j.actaastro.2022.02.016.
25

equation... Such that at 1 km, an unprotected base might expect as many as 8 

impacts per landing, each with a kinetic energy of∼23.5 J. At 5 km, one would 

expect a 37 % chance of impact, at 10 km, that falls off to a 10 % chance of impact 

for base of the same size and so on. Thus, the question of risk turns to a question of 

durability and materials. It is not a question of if an impact will occur, but how many 

impacts and how the vehicle or space suit handles it.54

Once operations on the lunar surface begin—particularly when multiple operations are in a single 

region (e.g., the South Pole)—policymakers and mission planners will need to decide how far apart 

landings should be from ongoing operations, or how to protect surface assets from nearby landing 

spacecraft. This is a difficult question because of existing gaps in knowledge and the extreme 

distances traveled by ejected debris. 

The drafters of the 2011 Recommendations were faced with a similar problem. They addressed this 

difficulty by estimating how far large particles (between 1 and 10cm) were likely to travel (1.5km), 

and therefore recommended that landings take place no closer than 2km from key Apollo sites.55 By 

discounting the (nonzero) dangers posed by smaller particles and dust, they were able to constrain 

a protective zone around Apollo sites. A similar analysis could be useful now. According to leading 

experts in the field, the most useful measure of the danger posed by particles ejected by PSIs is 

energy flux: the total energy transmitted by ejected particles at various distances from a landing 

site, taking into account the mass, velocity, and number of particles striking an object at that 

distance from landing.56 NASA could focus its investigations into this energy flux with the goal of 

identifying standoff distances from landing sites that will reduce the flux to tolerable levels. Mission 

planners could then refrain from landing craft within that distance from other operations taking 

place on the lunar surface. These distances will vary based on the size and engine configuration of 

landing craft, as well as the surface properties of the landing site. We recognize that landers will not 

target single points on the lunar surface: CLPS and HLS contracting documents require those landers 

to land within a certain radius of target locations, as described above. The landing target radius 

should be combined with the safety distance, such that a lander touching down on the edge of its 

target radius remains far enough away from other operations that existing operations on the 

surface are unlikely to experience high levels of energy flux. This focus has the advantage of 

ultimately developing technically based, publicly articulable justifications for our landing choices. 

Instead of developing landing safety distances for each mission, some SMEs have recommended 

that NASA adopt simple, easily understood standard distances, at least until PSI models improve: 

i.e., “all CLPS missions should land x meters from currently-operating hardware” or similar. 

54 M. M. Wittal, et al., “The Behavior of High-Velocity Dust Generated by Lander Plumes in the Lunar Environment,” 

AAS 20-511 (June 2020): https://ntrs.nasa.gov/citations/20205003590. 

55 See discussion above, as well as in the Heritage section below. 

56 Dr. Philip Metzger, email to the authors, July 27, 2022. 
26

Adopting such a measure would simplify mission planning, avoid limitations in current PSI models, 

and ease communication with the broader space community. However, adopting blanket 

measures—even in the short term—raises the risk of creating a perception that these measures are 

arbitrary and possibly attempts to displace other actors or otherwise “seize control” over certain 

areas. 

Based on our conversations with partner space agencies, we understand that at least one of them is 

investigating the dangers of PSIs and considering how to reduce those dangers. As cooperative 

missions develop, it will be important to combine data as a first step towards developing joint PSI 

models and agreed safety measures. As the space community’s knowledge improves, it may be 

possible to develop broadly-agreed-to standards for how PSIs can be predicted, measured, and 

their dangers avoided. NASA SMEs could begin cooperative PSI prediction, measurement, and 

safety work with partner agencies and the private sector with the goal of developing “gold 

standards” for PSI predictions. Ultimately, shared models and common standards could create 

predictability and reduce disagreements between operators regarding landing safety. As a longterm goal, international standard-setting processes such as those managed by the International 

Organization for Standardization (ISO) could be adopted to unify operator treatment of PSI-related 

risks. After NASA SMEs begin cooperative work with partners to understand PSI risks, NASA could 

work with those partners to explore the possibility of formal standardization as a long-term goal. 

There are limits to these recommendations. As described, focusing on avoiding particularly high 

energy flux will not eliminate the risk of impacts to other objects operating on the lunar surface. 

Impacts can and will occur, so shielding and other steps may be necessary. Additionally, in relatively 

small areas such as the Connecting Ridge, it may be difficult to find areas that are far enough away 

from ongoing operations to provide suitable landing sites, particularly taking into account the need 

to combine landing accuracy radii with safety margins as described above. Landing large distances 

away from places of interest (e.g., surface habitat or scientifically interesting locale) will also require 

long traverses, adding another level of complexity. 

As the lunar surface becomes crowded in certain locations, these safety measures for landings will 

become simultaneously more important and more difficult to implement. We also note that 

landings are not the only time when PSIs and similar risks can occur; launching from the lunar 

surface could also pose risks to nearby operations. NASA and partners should consider placing a 

priority on the development of landing and ascent infrastructure, such as prepared landing and 

ascent surfaces, in areas that are likely to experience multiple operations in close proximity. 

Prepared surfaces could significantly reduce the danger of large ejecta, thus allowing landings and 

surface ascents to be closer to ongoing operations. Safety berms and similar naturally occurring 

features might also be useful in decreasing this safety distance. 

In terms of timing, the hazards posed by landings to other ongoing operations will not materialize 

until multiple activities are occurring in proximity. NASA and the lunar community have a period of 
27

time to build on their knowledge of PSIs and other issues—and to develop shared metrics and 

mitigation steps—so that once landings begin to occur near each other, we will have more 

information upon which to determine specific safety distances. 

Table 5. Challenges Posed by Landings: Summary of Policy Tools and Corresponding Rationale. 

Landings will create PSIs that can damage assets—significant gaps in understanding their effects 

exist. 

Policy Tool Rationale 

NASA could increase the priority of obtaining PSI 

measurements when possible. Mission planners could 

look for opportunities for dedicated PSI 

measurements spanning more missions or obtain 

data by indirect means if that is not possible. Data 

regarding PSIs should be shared publicly, consistent 

with longstanding NASA practice.

PSI prediction models require realworld data to validate simulations 

and inform safety measures. Absent 

accurate models, standoff distances 

will need to be larger than might be 

possible with accurate predictions. 

NASA could focus its investigations into this energy flux 

[from ejected particles] with the goal of identifying 

standoff distances from landing sites that will reduce 

the flux to tolerable levels. We recommend that we 

refrain from landing craft within that distance from 

other operations taking place on the lunar surface.

Energy flux is the metric preferred 

by most SMEs in the academic and 

NASA community; it most closely 

predicts impacts on operators. 

 NASA SMEs could begin cooperative PSI prediction, 

measurement, and safety work with partner agencies 

and the private sector with the goal of developing 

“gold standards” for PSI predictions. 

Cooperative PSI models can be more 

persuasive to the broader space 

community than would U.S.-centric 

models, and likely more accurate 

due to greater data availability. 

After NASA SMEs begin cooperative work with partners 

to understand PSI risks, NASA could work with those 

partners to explore the possibility of formal 

standardization as a long-term goal.

PSI modeling is a technical safety 

measure; handling it through 

technical bodies could reduce 

potential for political influence, 

create predictability among 

operators, and standardize safety 

measures so as to avoid a “race to 

the bottom.”
28

Policy Tool Rationale 

NASA and partners could place a priority on the 

development of landing and ascent infrastructure, 

such as prepared landing and ascent surfaces, in areas 

that are likely to experience multiple operations in 

close proximity. 

Landing and ascent infrastructure 

can reduce the need for landing and 

ascent standoff distances and thus 

allow more operations in proximity. 

2.2 Threats to and from Surface Operations 

While landings on the Moon create the most dramatic risk to surface assets, surface operations also 

pose risks. These risks vary based on the nature of operations and hardware. Some operations may 

be at little risk of causing or suffering from harmful interference, while other operations may 

involve greater risk. Sometimes, these hazards are the result of nominal operations; other times, 

they would arise if equipment were damaged. For example, microwave and other transmitters can 

cause undesired thermal effects in other equipment, and ISRU processing might cause regolith to be 

ejected. Nuclear power sources, fuel depots, and even relatively small pressure vessels pose 

explosion, radiation, and other risks if damaged. 

Artemis partners have coalesced around the idea of “safety zones” to manage these sorts of 

dangers. Defining safety zones, the Artemis Accords states: 

The area wherein this notification and coordination will be implemented to avoid 

harmful interference is referred to as a ‘safety zone’. A safety zone should be the 

area in which nominal operations of a relevant activity or an anomalous event could 

reasonably cause harmful interference. 

Phrased plainly, a safety zone is an area where one’s own activities might cause interference to 

others if they came into the area or in which their presence might cause interference to one’s own 

operations. Other actors are not required to stay out of safety zones; they are to notify the creator 

of the zone before entering and consult in advance to mitigate the interference. 

The creation of safety zones on the Moon would be a significant operational, legal, and geopolitical 

step. As we discuss below, although safety zones derive from concepts in the Outer Space Treaty, 

they could be abused, and even reasonable safety zones could subject NASA and the United States 

to international criticism. It is therefore important to understand the legal, historical, and 

operational bases for this policy tool. 

One slight precedent is the International Space Station (ISS). NASA has established a small “keepout sphere” around the ISS, but this is a requirement for certification of commercial craft visiting 

the station, not a generally applicable rule for space actors. Because the details of this requirement 
29

are subject to International Traffic in Arms Regulations (ITAR), it is not discussed further here.57

Regardless, this requirement is essentially a safety requirement for NASA’s own contractors, so it is 

not a close analogy to the multi-actor safety zones envisioned by the Artemis Accords and needed 

on the Moon. 

The 2011 Recommendations provide another example. As described in detail above, these 

recommendations request space actors to refrain from surface approaches to Apollo and Surveyor 

sites within certain distances, based on the characteristics and perceived value of those sites. 

The ISS keep-out sphere and the 2011 Recommendations provide precedents from which 

policymakers can draw when designing safety zones on the Moon. However, the ISS and 2011 

Recommendations were narrowly scoped and unilateral. To design and implement the concept of 

safety zones created by the Artemis Accords requires examination of the unique features of the 

Moon and Artemis campaign missions. 

Before examining how safety zones could be implemented, it is important to understand what 

safety zones are. Section 11 of the Artemis Accords provides the most detailed, recent explanation 

of this policy tool. As a high-level commitment among international partners involved in the Artemis 

campaign, the Accords defines safety zones and describes how they are to be implemented for 

purposes of NASA operations on the Moon and, therefore, this report.58

The most critical element of safety zones is what they are not: they are not exclusion zones. Article I 

of the Outer Space Treaty declares that “there shall be free access to all areas of celestial bodies.”59

As a party to this treaty, the United States has no legal ability to exclude other actors from locations 

on the Moon. At the same time, other portions of the Outer Space Treaty provide building blocks 

from which safety zones can be constructed. 

Article IX of the Outer Space Treaty requires states to give “due regard to the corresponding 

interests” of other states operating in space. Additionally, that article of the Treaty requires 

consultations prior to any activities that might create “harmful interference” in the activities of 

others in space, and Article VIII confirms that states retain ownership, jurisdiction, and control over 

their objects in outer space. One of the most useful achievements of the Artemis Accords is to 

combine these elements—due regard, consultations prior to interference, and the exercise of 

control over objects—into the tool that we call “safety zones.”

57 NASA-authored references not subject to ITAR can be found at 

https://ntrs.nasa.gov/api/citations/20100014822/downloads/20100014822.pdf, 

https://ntrs.nasa.gov/citations/20150010757, and 

https://ntrs.nasa.gov/api/citations/20150010757/downloads/20150010757.pdf

58 Additional discussion of the Artemis Accords and the Outer Space Treaty is contained in Appendix A. 

59 Because this provision is relevant to many of the policy tools described in this report, further discussion of the 

provision is provided elsewhere. 
30

The Accords provides guidance regarding the design of safety zones, and commits signatories to the 

following principles: 

(a) The size and scope of the safety zone, as well as the notice and coordination, 

should reflect the nature of the operations being conducted and the environment 

that such operations are conducted in; 

(b) The size and scope of the safety zone should be determined in a reasonable 

manner leveraging commonly accepted scientific and engineering principles; 

(c) The nature and existence of safety zones is expected to change over time 

reflecting the status of the relevant operation. If the nature of an operation 

changes, the operating Signatory should alter the size and scope of the 

corresponding safety zone as appropriate. Safety zones will ultimately be 

temporary, ending when the relevant operation ceases; and 

(d) The Signatories should promptly notify each other as well as the SecretaryGeneral of the United Nations of the establishment, alteration, or end of any safety 

zone, consistent with Article XI of the Outer Space Treaty. 

The Accords further state that “The Signatory establishing, maintaining, or ending a safety zone 

should do so in a manner that protects public and private personnel, equipment, and operations 

from harmful interference.”

Taken together, these criteria provide guidelines for our own establishment of safety zones around 

NASA’s lunar operations. The criteria described in Section 11(7)(a-b) of the Accords are those 

relevant to the design of safety zones, and we examine them here. 

To reiterate: “The size and scope of the safety zone, as well as the notice and coordination, should 

reflect the nature of the operations being conducted and the environment that such operations are 

conducted in...The size and scope of the safety zone should be determined in a reasonable manner 

leveraging commonly accepted scientific and engineering principles.”

Because equipment will vary, detailed recommendations for safety zones are not possible at this 

time. We understand that a general rule—i.e., “safety zones should be 2km wide”—would be 

simple to implement, but there is no technical basis for such blanket determination and doing so 

would be inconsistent with the factors set out in the Accords. We are therefore unable to 

recommend a generalized design for safety zones. However, based on conversations with SMEs, we 

have been able to identify a minimum set of considerations that should be taken into account when 

considering dangers posed by surface operations. We recommend that for each mission, planners 

identify and quantify to the extent possible dangers posed by: 

• Regolith ejected from the surface as the result of rover travel or other movement 

• Pressure vessels during normal operations, at end of life, and in the event of failure 
31

• Shadowing caused by tall structures 

• Non-ionizing radiation from all sources 

• Ionizing radiation from all sources 

• Any chemicals released during normal operations or in the event of failure 

• Any other hazards unique to specific hardware or operations (e.g., nuclear power systems) 

• Special hazards posed by the nature of the location or terrain (e.g., significant slopes, boulders, 

dust, surface, or regolith characteristics) 

• Damage to instrumentation (i.e., sensors, seismometers, or other instruments that may be 

damaged due to nearby landings and/or operations)

• Waste disposal 

We have also worked with SMEs and used existing literature and knowledge to develop a system for 

designing and implementing safety zones. Policymakers could work with mission planners to (a) 

identify risks that each element of a mission could cause to others using the checklist above, (b) 

identify risks that other actors might cause to our own operations, and (c) identify a radius or other 

distance around each activity that can reasonably minimize (but likely not eliminate) those risks. 

These steps could become a standard element of mission planning, at least when multiple missions 

are operating in proximity. Safety zones could be tailored to the specific circumstances of our 

activities, but also take into account the geographical and other features of the target site (e.g., the 

presence or absence of ridges, boulders, etc. that could provide physical protection). Additional 

steps, such as the creation of protective berms, landing pads, and siting such objects inside craters, 

could be considered as part of mission planning to minimize the size and need for safety zones. The 

justifications for these safety zones should be clearly communicated to the space community.60

The issue of overflight deserves brief mention. In addition to applying to surface operations, safety 

zones also apply to activities that could accidentally become surface operations: that is, crashes. 

Respect for safety zones entails designing overflight paths and descent trajectories in such a way as 

to avoid instantaneous impacts inside safety zones.61

Once safety zones have been designed, implementation is relatively straightforward. Building on 

the transparency mechanisms discussed later in this report, the establishing actor (the U.S. 

Government / NASA, JAXA, etc.) needs to communicate the details of safety zones to the space 

community so that others can respect these zones. As promised by the Artemis Accords, we should 

be able to provide technical justifications for the design of each safety zone as described above. The 

Accords are clear that safety zones should be justified to the international community, but that the 

60 See the Transparency section below. 

61 This follows the precedent of the 2011 Recommendations, which request space-faring entities to avoid 

instantaneous impact possibilities within exclusion zones. 
32

decision to implement them—and the design of them—rests with the actor engaged in the 

operations. 

For signatories to the Artemis Accords, respect for safety zones means that signatories have 

promised to notify each other of safety zones, notify each other if a later actor wishes to enter an 

existing safety zone, and then to consult to mitigate any interference that might arise from that 

entry into the area. 

Regarding non-signatories to the Accords, implementation is similar. Although non-signatories have 

not promised to respect safety zones as described in the Accords, all space-faring nations are 

parties to the Outer Space Treaty. As described above, that treaty requires them to give “due 

regard” to the interests of others, and to notify and consult in advance of any actions that might 

cause harmful interference. By publicly establishing safety zones around own operations, we have 

put the international community on notice that any entry into these areas could cause harmful 

interference, thus triggering the notice and consultation requirements of Article IX. The end result is 

therefore the same for signatories and non-signatories to the Accords: notice and consultation. Any 

disagreements regarding the application of the Outer Space Treaty should be resolved through 

diplomatic channels. 

There are potential downsides to the establishment of safety zones on the Moon. Although they are 

emphatically not “keep out” zones, some critics—notably the Russian government, but also 

academics—have attempted to portray the safety zone features of the Artemis Accords as an 

American attempt to claim portions of the Moon.62,63 The actual establishment of safety zones 

could reignite those criticisms. Minimizing the size and number of safety zones, terminating them at 

the end of missions,64 and providing reasonable scientific and technical justifications for zone design 

may mitigate geopolitical repercussions. 

Another way to mitigate criticism of safety zones is to respect those of others. As a signatory of the 

Artemis Accords, we have already committed to respect the safety zones of other signatories. In 

addition to fulfilling that promise, we recommend that NASA and the U.S. Government respect 

safety zones or similar tools established by non-signatories as well, since the concept of safety 

zones is directly derived from the Outer Space Treaty. As long as non-signatories’ safety zones are 

reasonable, they should be respected. 

Of course, some actors may attempt to establish unreasonable safety zones or take similar 

attempts to “cordon off” large areas around their operations. If another actor were to do so, we 

62 Walker A. Smith, “Using the Artemis Accords to Build Customary International Law: A Vision for a U.S.-Centric 

Good Governance Regime in Outer Space,” J. Air L. & Com. 86 (2021): https://scholar.smu.edu/jalc/vol86/iss4/5. 

63 “Nasa proposals to allow establishment of lunar 'safety zones',” Science, The Guardian, last modified May 25, 

2020, https://www.theguardian.com/science/2020/may/20/nasa-new-space-treaty-artemis-accords-moonmission-lunar-safety-zones. 

64 Or, if residual danger exists (i.e., from remaining pressurized vessels), reducing the zone as much as possible. 
33

should work with the State Department (if the other actor is international) or the space interagency 

(if the other actor is U.S. commercial) to respond. This response should keep in mind that safety 

zones are simply a mechanism for implementing existing obligations set out in the Outer Space 

Treaty: the obligations to give due regard and consult before interference. We could use our own 

technical knowledge to judge whether other actors’ requests are premised on a realistic fear of 

interference; to the extent they are not, we could communicate that we do not recognize them as 

legitimate, but also explain what sort of safety zones or other measures we would consider 

justified. Ultimately, respect for safety zones—whether our own or others’—is an exercise in 

persuasion, applying mission and hardware-specific facts to existing legal obligations. This would be 

the case whether the Artemis Accords or the concept of safety zones existed; safety zones are 

simply a mechanism to regularize implementation of the Outer Space Treaty. 

Respect for many actors’ safety zones does have its own downsides. As lunar operations proliferate, 

the number of safety zones in place at any one time will increase. The need to provide notice, and 

then coordinate operations to minimize interference, may add complications to mission planning. In 

a rules-based system, this complication is largely unavoidable. 

As a practical matter, safety zones will not be needed until operations begin occurring in 

overlapping locations on the Moon. However, arguments exist for implementing safety zones 

earlier, even when not operationally necessary; we discuss this in our Implementation section 

below. 

Table 6. Threats to and from Surface Operations: Summary of Policy Tools and Corresponding Rationale. 

Activities on the surface can cause damage to or interfere with surface assets and operations. 

Policy Tool Rationale 

We recommend that for each mission, planners 

identify and quantify to the extent possible 

dangers posed by:

• Regolith ejected from the surface as the result 

of rover travel or other movement

• Pressure vessels during normal operations, at 

end of life, and in the event of failure

• Shadowing caused by tall structures

• Non-ionizing radiation from all sources

• Ionizing radiation from all sources

• Any chemicals released during normal 

operations or in the event of failure

Adopting a standard checklist of 

hazards to identify and use to 

construct a safety zone will simplify 

planning, standardize mission 

design, and enhance our ability to 

justify safety zones and other 

measures to other actors. 
34

Policy Tool Rationale 

• Any other hazards unique to specific hardware 

or operations (e.g., nuclear power systems)

• Special hazards posed by the nature of the 

location or terrain (e.g., significant slopes, 

boulders, dust, surface, or regolith 

characteristics)

• Damage to instrumentation (i.e., sensors, 

seismometers, or other instruments that may 

be damaged due to nearby landings and/or 

operations)

• Waste disposal

Policymakers could work with mission planners to 

(a) identify risks that each element of a mission 

could cause to others using the checklist above, 

(b) identify risks that other actors might cause 

to our own operations, and (c) identify a radius 

or other distance around each activity that can 

reasonably minimize (but likely not eliminate) 

those risks.

This option implements the 

commitments set out in the Artemis 

Accords. 

The design of safety zones could become a 

standard element of mission planning. Safety 

zones could be tailored to the specific 

circumstances of our activities, but also take 

into account the geographical and other 

features of the target site (e.g., the presence or 

absence of ridges, boulders, etc. that could 

provide physical protection).

This option implements the 

commitments set out in the Artemis 

Accords. 

Additional steps, such as the creation of protective 

berms, landing pads, and siting such objects 

inside craters, could be considered as part of 

mission planning to minimize the size and need 

for safety zones. 

Other safety measures can minimize 

the size and need for safety zones 

and similar measures, allowing more 

actors to operate in proximity. 
35

2.3 Challenges to Moving Across the Lunar Surface 

Through our work with NASA SMEs, we learned that a confluence of technical constraints may 

result in another challenge for lunar surface operations: the need to maintain our ability to travel 

on the surface of the Moon between landing sites and/or areas of interest. As described in Part I, 

solar-powered robotic and crewed vehicles will need to follow pre-planned pathways if they travel 

on the surface between locations in the south polar region. These pathways will be designed to 

maximize time spent in sunlight, minimize time spent in shadow, and follow terrain features that 

are traversable by anticipated vehicles. Computer modeling shows that in some cases, sections of 

these corridors are extremely narrow: as small as 20-40 meters wide.65 This modeling includes 

technical assumptions about the rover such as a fixed solar panel height of two meters above the 

surface and maximum speed of one to three kilometers per hour for the rovers.66

Until lunar rover designs are selected, our knowledge of their technical constraints is based on 

assumptions such as these. As a result, models demonstrating the need for very narrow transit 

pathways may over- or underestimate the difficulty of identifying paths across the lunar surface. 

Nevertheless, if current assumptions are accurate and some transit pathways are so narrow and so 

potentially critical to NASA and other actors’ operations, then it is important to ensure that they 

remain available for use.67

We recommend that mission planners optimize traversable pathways between landing sites and/or 

other sites of interest. Models can be revisited if and especially when more details on rover 

capabilities become known. Additionally, the agency could work with international partners whose 

missions may overlap with or benefit from the identification of these pathways. If rovers could be 

deployed that could survive, e.g., 200 hours of darkness, additional pathways might appear, and the 

paths identified to date might not be so restrictive. It is important to test the validity of 

assumptions underlying our current planning. 

Current modeling is also based on an assumption that no supplemental power exists to support 

surface assets in transit between sites of interest. However, certain architectures, as well as 

ongoing talks with international partners, call for the deployment of solar, nuclear, or other power 

solutions that could provide supplemental power at key locations between areas of interest near 

65 P. Glaser et al., “Illumination conditions at the lunar poles: Implications for future exploration,” Planetary and 

Space Science 162 (Nov. 2018): https://doi.org/10.1016/j.pss.2017.07.006. 

66 These vehicles have not yet been selected, so their abilities are notional. NASA intends to release an RFP in late 

August of this year; the specific capabilities and limitation of lunar rovers will only be known once vehicle designs 

are finalized. 

67 Based on discussions with SMEs, we understand that secondary, tertiary, etc. pathways may also be identified, 

as well as utility corridors. The recommendations here focus on the most desirable, primary pathways, but 

additional corridors should be considered for protection if operationally necessary. 
36

the lunar South Pole. If charging stations or similar assets became available, options for when and 

how to travel on the Moon would change. 

Assuming that transit paths are truly rare and narrow and will remain so even as we deploy 

additional equipment to the lunar surface, policymakers could consider the creation and protection 

of “transit corridors” in the south polar region. Transit corridors are navigable pathways between 

potential areas of interest optimized to avoid darkness and terrain-related constraints. NASA could 

(1) identify these corridors, (2) make their locations publicly known, (3) refrain from placing or 

disposing of equipment or facilities in these corridors (with an exception described below), and (4) 

request other space actors to exhibit the same restraint, at least until our capabilities advance 

beyond the need to avoid long periods of darkness. Avoiding the placement of objects in these 

corridors can ensure that they remain available for future operations. The identification and 

protection of transit corridors is likely not possible until specific details of hardware have been 

finalized but should occur as soon as possible (assuming it is necessary at all) as a prophylactic 

measure. 

The need to refrain from placing hardware in transit corridors is not absolute. As we discuss above, 

some architecture plans call for the establishment of stationary facilities at which mobile assets 

could recharge their batteries.68,69,70 If these facilities are solar-powered, they would likely be 

situated on high-elevation points along areas where mobile assets are likely to travel—precisely the 

same sort of areas likely to be along the transit corridors we have identified. Likewise, some mission 

plans have called for radiation and other emergency equipment to be deployed in areas where crew 

plan to travel. If fixed facilities are deployed in areas where mobile assets are likely to operate, we 

recommend that they be provided with visual and radio beacons and their locations made publicly 

known. In all cases, these facilities should be situated so as not to block mobile vehicles, including 

large, crewed rovers, from transiting the area. 

There are potential downsides to the protection of transit corridors. Refraining from placing or 

disposing of hardware in these areas may place operational limitations on missions. Just as with all 

restrictions, this could result in additional costs or reduced capabilities for specific missions. If 

scientifically useful sites were to be identified along transit corridors, we may be less able to 

investigate them with persistent platforms than we could in the absence of protected transit 

corridors. 

68 “NASA’s Plan for Sustained Lunar Exploration and Development,” NASA, accessed June 17, 2020, 

https://www.nasa.gov/sites/default/files/atoms/files/a_sustained_lunar_presence_nspc_report4220final.pdf. 

69 “Fission System to Power Exploration on the Moon’s Surface and Beyond,” Space Tech, NASA, last modified 

November 19, 2021, https://www.nasa.gov/feature/glenn/2021/fission-system-to-power-exploration-on-themoon-s-surface-and-beyond. 

70 “NASA, Industry to Mature Vertical Solar Array Technologies for Lunar Surface,” Space Tech, NASA, last modified 

March 23, 2021, https://www.nasa.gov/feature/nasa-industry-to-mature-vertical-solar-array-technologies-forlunar-surface. 
37

More generally, transit corridors could raise similar concerns in the space community to those 

posed by safety zones: that NASA or the United States are unilaterally attempting to place certain 

areas off-limits, despite the Outer Space Treaty’s provisions regarding free access to all areas of 

celestial bodies. These concerns could be mitigated by clearly stating that we are imposing the 

same restrictions on ourselves that we are asking the rest of the community to adopt, and by 

emphasizing that the goal is to maintain access to polar sites for all of humanity. Alternatively, 

NASA and the U.S. Government could work with other space agencies and the international 

community to develop some level of consensus about the need for transit corridors before calling 

for their protection. Finally, we could characterize transit corridors as temporary measures, needing 

protection only until additional rover or power capabilities exist. 

Table 7. Challenges to Moving Across the Lunar Surface: Summary of Policy Tools and Corresponding Rationale. 

Technical constraints limit the ability to move between areas of interest—there is a need to ensure 

navigable pathways remain available for use. 

Policy Tool Rationale 

We recommend that mission planners optimize 

traversable pathways between landing sites and/or 

other sites of interest. Models can be revisited if and 

especially when more details on rover capabilities 

become known. Additionally, the agency could work 

with international partners whose missions may 

overlap with or benefit from the identification of 

these pathways.

It is critical to determine whether 

paths between areas of interest or 

landing and operations sites are rare 

and small, thus requiring protection. 

The creation and protection of “transit corridors” in the 

south polar region could be considered.

If certain corridors are critical to 

surface operations, protecting our 

ability to continue to use them is 

also critical to those future 

operations. 

NASA could (1) identify these corridors, (2) make their 

locations publicly known, (3) refrain from placing or 

disposing of equipment or facilities in these corridors 

(with an exception described in this report), and (4) 

request other space actors to exhibit the same 

restraint, at least until our capabilities advance 

beyond the need to avoid long periods of darkness.

These steps would ensure that 

critical transit corridors remain 

available for future missions by 

NASA and other actors, while still 

allowing their use in the meantime. 
38

Policy Tool Rationale 

If fixed facilities are deployed in areas where mobile 

assets are likely to operate, we recommend that they 

be provided with visual and radio beacons and their 

locations made publicly known. In all cases, these 

facilities should be situated so as not to block mobile

vehicles, including large, crewed rovers, from 

transiting the area.

Some fixed facilities may be required 

in corridors; these measures would 

minimize the impact of those 

facilities and allow operators to work 

around them (literally in some 

cases). 

2.4 The Danger of Radio-Frequency Interference 

SMEs also suggested that we consider challenges posed by radio-frequency interference (RFI) 

among lunar operations and examine whether specialized policy tools are appropriate. 

Like those in orbit, lunar operations certainly could be subject to RFI. However, because this hazard 

is not unique to the lunar environment, we have identified no reason to diverge from the same 

solutions used to avoid RFI on Earth and in Earth orbit: international coordination through the ITU. 

The ITU already allocates frequencies for use by space objects, and it is set to place special 

emphasis on emerging space needs at the next World Radiocommunication Conference in 2023.71

NASA already engages with the Federal Communications Commission (FCC), the National 

Telecommunications and Information Administration (NTIA), and the Department of State to 

prepare the U.S. Government’s positions before the ITU and then implement frequency allocations, 

and uses internationally allocated frequencies for communications.72 We recommend that NASA 

continue this engagement with the interagency and continue to rely on the ITU to avoid RFI in lunar 

operations. If additional international mechanisms ultimately prove to be needed (e.g., rules 

combining frequencies and locations such as those for geosynchronous orbit (GEO) satellites), NASA 

should work with the interagency to develop, promote, and implement those policies through the 

ITU. 

Table 8. The Danger of Radio-Frequency Interference: Summary of Policy Tool and Corresponding Rationale. 

Surface operations could be subject to radio-frequency interference. 

71 “Managing radio frequency spectrum amid a new space race,” News, International Telecommunication Union, 

last modified November 12, 2021, https://www.itu.int/hub/2021/11/managing-radio-frequency-spectrum-amid-anew-space-race/. 

72 For an explanation of the interagency process from the perspective of NASA, see Spectrum 101, 2016, at 

https://www.nasa.gov/sites/default/files/atoms/files/spectrum_101.pdf. 
39

Policy Tool Rationale 

We recommend that NASA continue engagement with 

the interagency and continue to rely on the ITU to 

avoid radio-frequency interference in lunar 

operations.

The ITU appears to be engaged in a 

process to resolve issues relating to 

deep-space communications. The 

ITU has successfully resolved similar 

issues in other space regimes, so is 

best positioned to allocate 

frequencies for lunar operations as 

well. 

2.5 Threats to Areas with Special Characteristics 

In our conversations with SMEs, several noted that certain locations in the south polar region of the 

Moon warrant special consideration due to unique or rare characteristics. Lunar operations pose a 

risk of rendering these locations less useful, so special measures may be appropriate. 

The first category of unique or rare sites are those with particularly high scientific value, especially 

PSRs located in large, old, relatively undisturbed craters. Locations with these characteristics are 

attractive to the scientific community as a potential “window” into the history of the solar system, 

and some experts have expressed a desire that they be protected from disturbance except for 

scientific investigation.73 Volatile-rich PSRs are also areas that could be useful for ISRU operations, 

so there is a possibility of tension between scientific, exploration, and (perhaps) commercial 

activities at these locations. 

Reserving locations for only scientific activities is possible but would require consensus among 

actors beyond NASA and the U.S. Government. No legal, policy, or diplomatic tools currently exist 

for this purpose; on the contrary, the Outer Space Treaty provides that “there shall be free access 

to all areas of celestial bodies.”74 NASA could make an internal decision to set aside certain PSRs 

(e.g., in the north polar region) for purely scientific activities with regard to its own missions, but 

ensuring that commercial and international actors exercise similar restraint would require securing 

consensus among them. If this is an effort NASA leadership wishes to pursue, SMD and other NASA 

leaders could engage with the scientific community to determine whether any locations exist that 

warrant being reserved for scientific purposes and, if so, collaborate with the Department of State 

and industry to secure the necessary broad consensus. We recognize that not all PSRs are equally 

valuable from scientific or other perspectives; small PSRs are likely to be common across the polar 

73 This idea is similar to how Antarctica is reserved for scientific purposes under the Antarctic Convention. 

74 In contrast to the Antarctic, where the Antarctic Treaty essentially reserves the entire continent for scientific 

purposes. 
40

regions, and frozen volatiles may only exist in some subset of PSRs. If special protections are desired 

for scientific or other uses, the space community should work to articulate which locations are 

especially valuable and for what purposes. Limiting the number of protected locations would 

increase the probability of success, as would reiterating NASA’s longstanding commitment to freely 

sharing the results of its scientific investigations. Because taking this step would mark a significant 

shift in national and international policy towards lunar exploration, we make no recommendation 

here as whether to pursue it. 

Another location in the polar region deserves special consideration for a very different reason: the 

Connecting Ridge between the Shackleton and de Gerlache craters. Many SMEs have emphasized 

the unique importance of this geographic feature: not because it is scientifically interesting, but 

because it provides critical operational advantages. The Connecting Ridge is a relatively open area, 

well-suited to landings; it receives substantial amounts of sunlight; and it offers surface access to 

many of the most desirable locations in the polar region, including PSRs, sunlit peaks, and suspected 

volatile deposits. Because of these characteristics, the Connecting Ridge is a highly desirable 

location for operations for NASA and other actors. 

Exclusive control over the Connecting Ridge is neither legally possible75 nor practical; the ridge is 

approximately twenty-five by ten kilometers in size. Attempting to control such a strategic location 

could also cause substantial political and diplomatic objections and would interfere with operations 

for all other actors. For these reasons, we recommend efforts be made to ensure freedom of access 

for all space actors to this region of the Moon, such as by exercising restraint when hardware is 

disposed in the area and consolidating operations sites when possible while still meeting mission 

objectives. 

Finally, a last location or series of locations, that may warrant specialized measures are sites where 

space resource extraction may occur on an ongoing basis. We note the importance of equity and 

ethics in Appendix D—specifically, how exploration can create tension between groups with 

differing values. Mining is one such example. Though long-term mining operations are largely out of 

scope for this analysis because they will not occur during the timescales covered by this report, we 

acknowledge the importance of near-term considerations to promote mining in an environmentally 

responsible way. Leveraging the strengths of international partners is one way to address this 

concern. Certain Artemis partners have extensive domestic histories of multi-stakeholder, 

environmentally responsible extractive industry work; they may be able to contribute to similar 

efforts for space resources. The Legal Subcommittee of the Committee on the Peaceful Uses of 

Outer Space (COPUOS) has formed a working group on space resources that may ultimately develop 

norms that could be incorporated into NASA’s planning. NASA is already represented on the U.S. 

delegation to that working group, but may wish to play a more substantive role once organizational 

75 See the discussion of freedom of access in the Outer Space Treaty above. 
41

questions about the group’s mandate are resolved. We recommend that NASA work with Artemis 

partners to jointly support UN space resource efforts directed at practical, actionable norms and 

best practices that support ISRU efforts and sustainable operations. 

Table 9. Threats to Areas with Special Characteristics: Summary of Policy Tools and Corresponding Rationale. 

Certain locations may warrant protection if operations may render them less useful. 

Policy Tool Rationale 

We recommend efforts be made to ensure freedom of 

access for all space actors to this region [the 

Connecting Ridge] of the Moon, such as by exercising 

restraint when hardware is disposed in the area and 

consolidating operations sites when possible while 

still meeting mission objectives.

The Connecting Ridge appears to be 

a potential area of landings and 

operations for multiple space actors, 

and central to NASA’s ability to 

operate across the polar region. 

Ensuring access for all to the Ridge 

implements provisions of the Outer 

Space Treaty and protects NASA’s

equities. 

We recommend that NASA work with Artemis partners 

to jointly support UN space resource efforts directed 

at practical, actionable norms and best practices that 

support ISRU efforts and sustainable operations.

ISRU efforts are some of the most 

controversial plans for our lunar 

programs and raise multiple policy 

issues. Engaging in multilateral fora 

is a way to minimize criticism and 

develop shared practices among 

multiple actors. 

2.6 The Challenge of Unexpected Activities on the Surface 

Throughout our conversations with SMEs, security-related concerns have been raised. For example, 

some individuals have expressed concerns that space actors hostile to U.S. Government programs 

could intentionally interfere with NASA’s lunar operations. Some have also raised concerns 

regarding theft or inadvertent release of proprietary or export-controlled technology as a result of 

operations between actors from different countries or companies. 

Our investigation has revealed no way to judge the likelihood of these risks, but they are at least 

physically possible. The creation of safety zones, described above, could serve to mitigate some of 

these risks, particularly the risk of inadvertent release of technology. 

However, a space actor willing to engage in intellectual (or physical) property theft, or to 

intentionally interfere with NASA operations, is unlikely to be deterred by a safety zone. For that 
42

reason, mission planners could consider including hardware that would allow them to identify and 

record any unexpected activities in their vicinity. This hardware need not be focused on only this 

one task: engineering cameras or other equipment could serve multiple purposes, so long as it is 

capable of recognizing and responding to proximity operations by other actors. Although adding 

cameras or other sensors could increase the mass, power requirements, and bandwidth required by 

lunar operations, this equipment could also be used for other purposes, such as navigation and 

public engagement. Power and bandwidth-preserving steps could also be taken, such as only 

transmitting data if nearby movement is detected—along the lines of a home doorbell camera. 

Including these capabilities on our missions could serve to deter threats and seek accountability if 

they materialize. If adding these capabilities is overly burdensome to apply to all lunar missions, we 

should consider whether specific missions warrant this level of protection due to the nature of 

equipment or operations involved. 

Table 10. The Challenge of Unexpected Activities on the Surface: Summary of Policy Tool and Corresponding 

Rationale. 

Security-related concerns could interfere with surface operations. 

Policy Tool Rationale 

Mission planners could consider including hardware that 

would allow them to identify and record any 

unexpected activities in their vicinity.

Recording equipment can help NASA 

respond to unexpected proximity 

operations, hazards, or other 

concerns as well as perform 

additional outreach and science 

tasks. 

2.7 The Need for Human Heritage Protection 

Another challenge—or at least a consideration—for lunar operations is the need to protect human 

heritage sites. SMEs, Congress, and civil society organizations have all emphasized their desire for 

NASA to include heritage protections in its operations. Doing so will require a combination of 

technical knowledge, historic insight, and diplomacy. 

As we mentioned above, this is not the first time the agency has examined this issue. In 2011, NASA 

published “Recommendations to Space-Faring Entities” regarding “how to protect and preserve the 

historic and scientific value of U.S. Government lunar artifacts.”76 These recommendations (also 

76 Human Exploration and Operations Mission Directorate, Strategic Analysis and Integration Division, NASA HQ, 

“NASA’s Recommendations to Space-Faring Entities: How to Protect and Preserve the Historic and Scientific Value 

of U.S. Government Lunar Artifacts,” July 2011: https://www.nasa.gov/pdf/617743main_NASAUSG_LUNAR_HISTORIC_SITES_RevA-508.pdf. 
43

discussed in the Safety Zones and Prior Work sections) focus on the Apollo and Surveyor sites, and 

provide detailed, non-binding suggestions to “help preserve and protect lunar historic artifacts and 

potential science opportunities for future missions.” To reiterate, the 2011 Recommendations 

specify details such as “exclusion zones,” “collision avoidance windows,” “artifact boundaries,” 

avoidance of overflight, and surface mobility boundaries. These recommendations differ for 

different Apollo sites based on (1) the perceived heritage value of the site (e.g., Apollo 11) and (2) 

whether the sites contain elements of ongoing scientific interest (e.g., laser ranging retroreflectors). Because the specific guidelines are set out above, we do not restate them here. 

In 2020, the Artemis Accords included a section on human heritage, ensuring that this is a shared 

goal among Artemis partners. Section 9 of the Accords states: 

The Signatories intend to preserve outer space heritage, which they consider to comprise 

historically significant human or robotic landing sites, artifacts, spacecraft, and other 

evidence of activity on celestial bodies in accordance with mutually developed standards 

and practices.77

The Signatories intend to use their experience under the Accords to contribute to 

multilateral efforts to further develop international practices and rules applicable to 

preserving outer space heritage. 

Also in 2020, the One Small Step to Protect Human Heritage in Space Act was adopted by 

Congress.78 This legislation requires NASA to “add the [2011 Recommendations and any subsequent 

similar recommendations] as a condition or requirement to contracts, grants, agreements, 

partnerships or other arrangements pertaining to lunar activities carried out by, for, or in 

partnership with [NASA].”79

We are therefore faced with a situation where we have detailed internal NASA guidelines for 

protecting the Apollo and Surveyor sites that we must also apply to commercial and international 

partnerships. No specific guidelines or legal requirements for other potential heritage sites exist, 

other than the general commitment in the Artemis Accords to “preserve outer space heritage.”

Protection of lunar heritage requires at least a two-step process: (1) identification of the sites to be 

protected and (2) development of measures that will protect those sites. For Apollo and Surveyor 

sites, both criteria are already met. We therefore recommend that the 2011 Recommendations be 

77 The Accords consider heritage to include “sites” as well as “artifacts” and “other evidence of activity.” When 

referring to heritage or heritage sites in this report, we adopt this broad definition. 

78 Public Law 116-275, Dec. 31, 2020. Available at https://www.congress.gov/116/plaws/publ275/PLAW116publ275.pdf. 

79 The law also provides for a waiver if the Administrator finds that carrying out this obligation in particular 

instances “would be unduly prohibitive to an activity or activities of legitimate and significant historical, 

archaeological, anthropological, scientific, or engineering value.”
44

continued and implemented for Apollo and Surveyor sites, and that their recommendations be 

implemented in commercial and international partnerships as required by law. 

Regarding future sites, the first step is identification. There is no formal international or domestic 

process through which these sites could be identified. During the negotiation of the Artemis 

Accords, drafting countries considered whether they should include heritage criteria in the Accords’ 

text. These countries decided that because heritage protections are of value to the entire 

international community—and because they could be abused (see below)—these criteria should be 

developed through multilateral diplomatic efforts.80 This has not yet occurred. 

Until a widely accepted method to identify heritage sites is developed by the international 

community, each spacefaring nation will need to determine which of their own sites deserve 

heritage protections and convince other actors to respect those decisions. For now, we recommend 

that NASA work with the Department of State and other relevant U.S. agencies and departments to 

identify which, if any, additional U.S. robotic or human sites warrant heritage protection. Because 

these sites will be indefinitely protected—and thus generally off-limits for operations—we 

recommend that NASA exercise extreme restraint in seeking heritage protection for future sites, 

particularly those in potentially crowded areas such as the south polar region. Heritage protection is 

also only appropriate after operations have ceased; while operations are ongoing, other policy 

tools, such as safety zones, are more well-tailored to protecting those activities. 

In order to identify other actors’ sites that might warrant heritage protection, we recommend that 

NASA work with the Department of State to determine whether other nations request heritage 

protection. Any dispute about the appropriateness of such a designation should be handled through 

diplomatic channels; if an internationally agreed upon process ultimately develops to identify 

heritage sites, that process should supplant this informal, diplomatic process. 

An internationally agreed upon process to identify heritage sites would provide many benefits. 

Terrestrially, processes such as those for United Nations Educational, Scientific and Cultural 

Organization (UNESCO) World Heritage Site designation and underwater archaeological sites have 

provided a level of neutrality, consensus, and certainty that is not possible under current space law, 

which does not explicitly provide for heritage protections. NASA could work with interagency 

experts on terrestrial heritage protections and the Department of State to (1) learn best practices 

for heritage site identification and (2) begin raising this issue in appropriate international fora such 

as COPUOS and potentially UNESCO itself. 

Once U.S. and international heritage sites have been identified, either through national processes 

(for now) or internationally agreed upon procedures (eventually), appropriate measures should be 

put in place to protect them. 

80 Personal knowledge of the authors. 
45

What it means to protect space heritage has not been decided by the international community. 

NASA is committed to implementing the 2011 Recommendations, but no protection measures have 

received broad acceptance for space. However, certain terrestrial analogues do exist; the closest is 

probably protections for maritime archaeology sites. 

One aspect of protection appears clear: heritage protections are intended to preserve cultural and 

historical value, not to enable development. Heritage protections would not be appropriate for 

locations in which we are engaged in ongoing operations. 

Until the international community develops more specific heritage protection measures for outer 

space, we recommend applying the recommendations set out in 2011 to heritage sites that are 

identified anywhere on the Moon, including in the polar region. Providing other actors’ sites—and 

our own future historic site(s)—the same protection as Apollo and Surveyor simplifies planning, 

minimizes the potential for claims of preferential treatment and creates consistency until an 

international standard is developed. 

There are potential downsides to heritage protection. Heritage protections raise many of the same 

concerns as do safety zones: some could claim that they are de facto “appropriation” of lunar 

territory, and/or that the United States and NASA should not speak on behalf of other actors when 

determining what sites beyond U.S. borders deserve protection. This risk is increased by the 

indefinite duration of heritage protections, but these risks are mitigated by the fact that heritage 

protections restrict our own activities as much as they do those of others, and by the fact that we 

are willing to apply these same protections to heritage sites from other countries. We could also 

draw from terrestrial heritage protections, such as maritime archaeological protections, when those 

precedents are useful. We recommend exercising restraint in identifying new heritage sites to 

minimize criticism and increase the likelihood that other actors will adopt similar protective 

measures. 

Any heritage sites should be identified and communicated to the space community as soon as 

possible to ensure protection, so we should consider whether NASA sites (such as the first Artemis 

crewed landing) warrant protection before those operations are complete. 

Table 11. The Need for Human Heritage Protection: Summary of Policy Tools and Corresponding Rationale. 

The U.S. may wish to preserve non-operational sites for their historic or cultural value. 

Policy Tool Rationale 

We recommend that the 2011 Recommendations be 

continued and implemented for Apollo and Surveyor 

sites, and that their recommendations be 

This ensures consistency in rules 

between what is required for our 

commercial actors and our own 

operations. 
46

Policy Tool Rationale 

implemented in commercial and international 

partnerships as required by law.

We recommend that NASA work with the Department of 

State and other relevant U.S. agencies and 

departments to identify which, if any, additional U.S. 

robotic or human sites warrant heritage protection. 

Because these sites will be indefinitely protected—

and thus generally off-limits for operations—we 

recommend that NASA exercise extreme restraint in 

seeking heritage protection for future sites, 

particularly those in potentially crowded areas such 

as the south polar region.

Balancing the need to protect 

legitimate heritage with the danger 

of creating backlash requires caution 

and an effort at persuading the 

community. 

We recommend that NASA work with the Department of 

State to determine whether other nations request 

heritage protection. Any dispute about the 

appropriateness of such a designation should be 

handled through diplomatic channels; if an 

internationally agreed upon process ultimately 

develops to identify heritage sites, that process 

should supplant this informal, diplomatic process.

If we request protection for our own 

sites, we must be willing to protect 

those of others as well. 

NASA could work with interagency experts on terrestrial 

heritage protections and the Department of State to 

(1) learn best practices for heritage site identification 

and (2) begin raising this issue in appropriate 

international fora such as COPUOS and potentially 

UNESCO.

Developing a formal, multilateral 

process is the only durable way to 

ensure indefinite heritage 

protections. 

We recommend applying the recommendations set out 

in 2011 to heritage sites that are identified anywhere 

on the Moon, including in the polar region.

This builds consistency in rules 

between Apollo, Surveyor, and 

Artemis sites. 

We recommend exercising restraint in identifying new 

heritage sites to minimize criticism and increase the 

Balancing the need to protect 

legitimate heritage with the danger 

of creating backlash requires caution 
47

Policy Tool Rationale 

likelihood that other actors will adopt similar 

protective measures.

and an effort at persuading the 

community. 
48

Part 3: Transparency, Coordination, and Implementation 

TOR Question 2: What technical and policy considerations should NASA take into account when 

implementing tools such as safety zones in order to protect these operations and U.S. interests? 

When implementing any of the policy tools described in Part 2, we recommend the following as a 

means to increase their effectiveness, thus protecting operations and U.S. interests. Note that this 

includes tools such as safety zones but applies to all of the policy tools. 

The first step in responding to the challenges posed by lunar operations is deciding how NASA 

wants to respond; the tools for doing so are described in Part 2. However, making our own 

decisions about how we wish to proceed is only the first step. For these decisions to be effective, 

we must also communicate those decisions to other actors, coordinate when necessary, and build 

our decisions into mission planning. This part of our report provides a set of options for doing so 

and is summarized in the following table. 

Table 12. Summarized Options to Supplement Policy Tools. 

Purpose Options to Supplement Policy Tools (See 

Summary Chapter for Full List) 

Transparency To address potential 

concerns and increase 

effectiveness of policy tools 

Build on the transparency section of the 

Artemis Accords by 1) meeting with 

signatories to discuss policy tools for 

upcoming missions and, 2) developing a 

public relations strategy along with 

multilateral engagement to explain rationale 

for policy tools 

Coordination To actively involve the 

space community before 

implementing policy tools, 

especially when related to 

cooperative missions 

Work with the Department of State to ensure 

partners on joint missions share our views on 

responding to challenges; develop 

mechanisms for consultation and 

coordination to deconflict surface operations 

Implementation To put policy tools into 

practice by incorporating 

into mission plans 

For missions over which NASA has 

operational control, build policy tools into 

mission planning; for missions operated as a 

service, work with contracting companies to 

implement relevant policy tools 
49

It is also worth keeping in mind that not all of the challenges discussed in Part II will be immediately 

important to our lunar operations. Some challenges—such as those posed by landings in proximity 

to ongoing operations—will only become a serious concern once traffic to the Moon increases. 

Other challenges may subside in importance as we develop additional lunar capabilities, such as 

through adoption of nuclear power, enabling travel through shadows. Policy and similar measures 

may not need to be adopted until challenges become imminent, but policymakers should also be 

aware that there may be benefits to deploying policy tools in relatively benign circumstances before 

testing them with “hard cases.” For example, as we discuss above, although safety zones may not 

become a practical necessity for a few years, we could nevertheless create safety zones for shortterm missions located far from any other actors, such as for early CLPS missions, as a way to 

establish precedent without imposing any difficulties on other actors. 

3.1 Transparency 

Most of the policy tools discussed in this report have never been used in outer space. In addition, 

some of these tools—particularly safety zones and heritage sites—could be abused, or be perceived 

to be abused, to (functionally if not legally) claim territory and displace other actors. Some 

commentators and national actors have already expressed concerns about safety zones along these 

lines.81,82 Much of this criticism has been about process, with countries such as China and Germany 

arguing that these issues should be discussed through traditional United Nations mechanisms. To 

blunt these concerns, it will be important to involve these fora whenever possible. In terms of 

substance, we will need to engage in a concerted effort to describe what we are doing and justify 

those actions to prevent negative political repercussions, maintain public and international support 

for our programs, and shape future behavior. 

Transparency can also serve practical goals. For policy tools to be effective, other actors must know 

that they exist so that they can respect them. 

The U.S. Government has already made a commitment to transparency in lunar operations in the 

Artemis Accords. Section 4 of the Accords is entitled “Transparency” and states that “the 

Signatories are committed to transparency in the broad dissemination of information regarding 

their national space policies and space exploration plans in accordance with their national rules and 

regulations.” In addition, the Accords contains additional transparency measures for specific issues: 

Section 8 commits signatories to “open sharing of scientific data” and Section 10 commits them to 

“informing the Secretary-General of the United Nations as well as the public and the international 

scientific community of their space resource extraction activities in accordance with the Outer 

81 Jack Wright Nelson, “Safety Zones: A Near-Term Legal Issue on the Moon,” Journal of Space Law 44, no. 2 (2020): 

https://ssrn.com/abstract=3849238. 

82 L. Mallowan, L. Rapp, M. Topka, “Reinventing treaty compliant ‘‘safety zones’’ in the context of space 

sustainability,” Journal of Space Safety Engineering 8 (June 2021): https://doi.org/10.1016/j.jsse.2021.05.001. 
50

Space Treaty.” The greatest level of detail is provided in Section 11 regarding safety zones and 

deconfliction of space activities. Here, commitments include: 

To provide each other with necessary information regarding the location and nature of space-based 

activities under these Accords if a Signatory has reason to believe that the other Signatories’ 

activities may result in harmful interference with or pose a safety hazard to its space-based 

activities; 

To provide notification of their activities and commit to coordinating with any 

relevant actor to avoid harmful interference; 

The Signatory maintaining a safety zone commits, upon request, to provide any 

Signatory with the basis for the area in accordance with the national rules and 

regulations applicable to each Signatory; and 

The Signatories should, as appropriate, make relevant information regarding such 

safety zones, including the extent and general nature of operations taking place 

within them, available to the public as soon as practicable and feasible, while taking 

into account appropriate protections for proprietary and export-controlled 

information.83

Finally, our commitment to transparency can keep us honest with ourselves. By ensuring that we 

are able to publicly articulate the justifications for our actions, we can help ensure that we are not 

overstepping or abusing our position as a dominant civil space actor. Some public reactions to 

NASA’s lunar operations will almost certainly be ethical in nature, as they were with Apollo.84,85 By 

adopting a clear commitment to transparency not only for our mission plans but also our policy 

tools, we can force ourselves to grapple with the social and ethical implications of our activities. 

For these reasons, implementing policy tools in our own missions is only the first step. We must also 

share this fact with the world and convince key actors that what we are doing is appropriate. If we 

do not believe that we can achieve that level of acceptance, we may wish to reconsider our choices. 

Fulfilling this need for transparency could come in many forms. As described, the Artemis Accords 

already contains some commitments: a general commitment to public sharing of policies and plans, 

open sharing of scientific information, providing the United Nations Secretary-General and scientific 

community information about space resource activities, and informing fellow Accords signatories of 

83 Artemis Accords, Section 11, excerpts. Intervening language omitted to focus on transparency obligations. 

84 Mark Williamson, “Space ethics and protection of the space environment,” Space Policy 19 (2003): 

http://www.chriscunnings.com/uploads/2/0/7/7/20773630/space_environment.pdf. 

85 “The Apollo 11 Mission and the Challenge of Solving the Plight of the Poor,” Blog, accessed June 17, 2022, 

https://launiusr.wordpress.com/2014/06/06/the-apollo-11-mission-and-the-challenge-of-solving-the-plight-of-thepoor/. 
51

safety zones. To meet these commitments as well as realize the full benefits of transparency, we 

recommend that NASA leadership consider several transparency measures. 

Most immediately, transparency requires communication with our commercial and international 

partners. As a first step, we recommend working with the Department of State to convene a 

meeting of Artemis Accords signatories—or a subset of them actively involved in lunar operations—

to discuss with them policy and related measures that we anticipate using for upcoming lunar 

missions. 

More public steps also have value, including formal United Nations processes. The United States is 

already obligated to provide basic space-object registration data to the United Nations pursuant to 

the Outer Space Treaty and Registration Convention. Furthermore, Article XI of the Outer Space 

Treaty commits Parties to “inform the Secretary-General of the United Nations as well as the public 

and the international scientific community, to the greatest extent feasible and practicable, of the 

nature, conduct, locations and results of [activities in outer space].” We could build on our 

longstanding registration practice and combine it with our Article XI obligations to provide formal 

notice to the international community of lunar operations, as well as associated measures such as 

safety zones. 

Notably, the civil society effort “The Article XI Project” is creating a draft template that states could 

use to provide the United Nations with precisely this sort of information.86,87 Working with the 

Department of State (which is responsible for our international registration filings), we could use 

this mechanism to provide not only registration data to the United Nations, but also data necessary 

for other actors to avoid conflicts with our operations. 

Public statements in the form of speeches and interviews by principals (the NASA Administrator and 

Deputy Administrator, the Vice President, and the Executive Secretary of the National Space 

Council) should also be used. Although not a useful vehicle to provide detailed operational data, 

these mechanisms are invaluable in explaining why we choose to take certain measures, and for 

describing what we are—and are not—doing. We could also discuss our lunar plans at the United 

Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS). 

Finally, we could continue to share information about exploration plans and missions on publicfacing assets such as NASA-controlled websites. In addition to the general information and scientific 

data typically provided, it may be useful to consider providing sufficient detail such that other 

actors could successfully deconflict their operations with our own. Barring that, we could provide 

contact information through which that sort of information could be shared. 

86 Italian Space Agency, discussion with the authors, June 6, 2022, and Antonino Salmeri, discussion with the 

authors, May 2022. 

87 “THE ARTICLE XI PROJECT,” Academics, Cleveland State University, accessed June 17, 2022, 

https://www.law.csuohio.edu/academics/globalspacelaw/projectXI. 
52

To summarize, we recommend a full public relations strategy, as well as multiple streams of 

multilateral engagement, to articulate our justifications for policy measures in order to forestall 

negative reactions and solidify our behavior as a precedent to be followed rather than a threat to 

the space community. 

Table 13. Transparency: Summary of Options and Rationale.

Options to Supplement Policy Tools Rationale 

We recommend working with the Department of State 

to convene a meeting of Artemis Accords 

signatories—or a subset of them actively involved in 

lunar operations—to discuss with them policy and 

related measures that we anticipate using for 

upcoming lunar missions.

Cooperative missions will require 

adoption of shared policy measures 

and achieving consensus among 

those measures will reduce criticism 

that they are illegitimate. 

We recommend a full public relations strategy, as well as 

multiple streams of multilateral engagement, to 

articulate our justifications for policy measures in 

order to forestall negative reactions and solidify our 

behavior as a precedent to be followed rather than a 

threat to the space community.

Adoption of the recommendations 

set out in this report will only be 

successful if these measures are 

understood and implemented by 

other actors. 

3.2 Coordination 

Transparency is a critical first, step but implementing our decisions will require further involvement 

with the space community: active coordination. The need for coordination when engaged in 

cooperative missions is obvious, but more general coordination will be required when multiple 

actors are operating in proximity on the Moon. 

Regarding cooperative missions, we recommend working with the Department of State during joint 

mission planning to ensure that our partners share our views regarding the steps necessary to 

respond to the challenges and threats described in this report. 

More general coordination will likely also become necessary, particularly when more than two 

space actors operate in proximity. In conversations with partner space agencies, one major partner 

expressed the view that some level of centralized coordination among actors may become 

necessary as lunar operations increase in number. Notice, coordination, and deconfliction measures 

are relatively straightforward for two actors, but once three or more actors are involved, the 

difficulty of, for example, establishing overlapping safety zones, will compound. This partner asked 
53

whether a single country or space agency should serve as a sort of convenor among parties involved 

in lunar operations, facilitating (but not deciding) solutions to common problems. 

Having any country serve as a centralized facilitator for lunar cooperation entails some risk. Other 

actors could perceive that role as a power-grab and it could also place the facilitator in an awkward 

position when mediating situations that involve its own agency’s or country’s operations. 

Nevertheless, it may become practically necessary to create formal coordination mechanisms. We 

recommend that policymakers work with the Department of State, industry, international partners, 

and ultimately the broader space community to develop mechanisms for consultation and 

coordination to deconflict operations on the Moon. To design these mechanisms, we could build on 

existing groups of partners and fora, such as Artemis Accords signatories and the International 

Space Exploration Coordination Group (ISECG). 

Finally, as we discuss above, there are certain issues—such as the danger posed by PSIs—that could 

benefit from standardization across the space community. For those issues, ad hoc coordination on 

a mission-by-mission basis may be sufficient in the short and medium-term, but the adoption of 

standardized measures could ultimately reduce the need to engage in detailed coordination 

because each actor would already know what safety measures they could expect to be followed by 

other operators. 

Table 14. Coordination: Summary of Options and Rationale. 

Options to Supplement Policy Tools Rationale 

We recommend working with the Department of State 

during joint mission planning to ensure that our 

partners share our views regarding the steps 

necessary to respond to the challenges and threats 

described in this report.

Cooperative missions will require 

adoption of shared policy measures 

and achieving consensus among 

those measures will reduce criticism 

that they are illegitimate. 

We recommend that policymakers work with the 

Department of State, industry, international partners, 

and ultimately the broader space community to 

develop mechanisms for consultation and 

coordination to deconflict operations on the Moon.

Deconfliction mechanisms require 

agreed processes across the space 

community. 

3.3 Implementation 

In addition to informing partners and the space community of our plans, we also need to put those 

plans into practice through mission planning. 
54

For example, CLPS missions could be designed to respect safety zones for each other and for HLS, 

and vice versa. Likewise, all NASA-affiliated missions could refrain from stationing or abandoning 

objects in critical transit corridors, or from interfering with heritage sites. Implementation in this 

sense is simply a question of mission planning—ensuring that the choices we have made to respond 

to lunar challenges are incorporated into operational plans. 

For missions over which NASA has operational control (e.g., HLS), operational implementation is 

relatively straightforward. Policy decisions should be communicated to relevant directorates, 

offices, and programs within the agency, and processes should be developed to ensure that these 

actors understand and build the appropriate policy decisions into their plans. 

For CLPS missions, and other missions operated as a service—where the contracting company, not 

NASA, has operational control—implementation may require additional effort. Because we do not 

directly control mission plans for these activities, NASA should consider working with relevant 

contracting companies to ensure that they build NASA-determined policy tools into their mission 

plans. The Office of the General Counsel and relevant program offices will need to be consulted to 

determine specifics for each mission, program, or contract. 

Not all policy measures described in this report would require such a level of control over our 

contractors. When policy measures would require our contractors to do or not do certain things—

such as avoiding heritage sites, including certain instruments on landers, or refraining from 

disposing of equipment in certain areas—we would likely need to work with contractors to include 

those requirements in contracting or other documents. However, for policy measures that entail 

requesting other actors to do or not do certain things, NASA and other departments/agencies may 

be able to implement them without a need to include those measures in contracting documents. 

For example: if we decided to establish a safety zone around a CLPS mission, we would not need to 

include any requirements in the contracting documents for that CLPS provider (other than possibly 

obtaining technical data in advance to help us design the safety zone). NASA, the Department of 

State, and the U.S. Government generally could design, publicize, and attempt to persuade other 

nations to respect that safety zone in their own operations. 

In addition to using contracting and similar mechanisms to implement policy measures for our 

commercial partners, U.S. Government regulators could choose to include these measures in their 

licensing requirements. It is currently unclear whether regulators have the legal ability to do so at 

present; the National Space Council-led regulatory reform process should clarify that question by 

the end of 2022 and may pursue regulatory reforms that would enhance regulators’ abilities to 

include requirements such as these in their licenses and authorizations. If regulators prove able and 

willing to do so, building these measures into the U.S. regulatory system would have the advantage 

of applying these measures to purely commercial activities—which NASA cannot directly control—

and of reducing the need for NASA to serve as a de-facto “regulator” of our commercial partners.
55

There may be financial and other costs to implementing the measures recommended in this report. 

Some place restraints on our own freedom of action, others would require certain technologies to 

be included in missions, and others would have impacts for our contractors. All of this entails costs: 

monetary costs but also opportunity costs by restricting our own behavior. OTPS does not have 

sufficient data to calculate the magnitude of those costs at this time. However, these measures are 

designed to further U.S. interests—including for safety of our own operations—with the ultimate 

goal of reducing risk and maintaining freedom of action for NASA and its partners. When 

considering whether to implement the recommendations contained in this report, all costs and 

benefits should be considered. 

We also recognize that implementing these measures would entail some level of administrative 

burden within NASA. For example, measures such as landing standoff distances and safety zones 

would require collection of technical data regarding specific craft and landing and operations sites 

and engaging in analysis to determine appropriate standoff and safety distances. Likewise, building 

these measures into mission planning would require taking policy considerations into account in a 

way that NASA does not routinely do, particularly for science and exploration missions. 

Nevertheless, whether or not NASA adopts the recommendations contained in this report or some 

similar measures, we will ultimately have to address the underlying concerns that motivated these 

recommendations in the first place. For example, even if we did not implement safety zones as set 

out in the Artemis Accords and this report, we would still need to respond to safety-of-operations 

issues posed by proximity operations once multiple actors are operating on the lunar South Pole. If 

the space community does return to the Moon with overlapping missions, engaging in the kinds of 

analyses we describe in this report will become a matter of operational necessity. The 

recommendations in this report are an attempt to regularize this work, ultimately leading to more 

predictable and safe operations. 

It is critical to recognize that these recommendations need not be implemented all at once, or for 

each mission or activity. It remains unclear how many U.S. and other activities will actually take 

place on the Moon close in time and space. Early missions, such as the first CLPS missions and

Artemis III, are unlikely to be near any other actors and are not planned to go near any existing 

heritage sites (Apollo and Surveyor). We could choose not to implement these measures unless and 

until overlapping operations are likely or certain, or to implement these measures piecemeal, 

adopting only those recommendations that provide substantial benefits or address substantial risks 

for specific missions and operations. 

Certain policy implications of lunar operations will only become pressing when the number of 

actors and activities in an area increases. For example, early missions will likely be able to proceed 

without using prepared landing pads, but an increased cadence of landings in vicinity to each other 

may require a prepared surface to mitigate plume and debris impingement. Likewise, disposal and 

potential salvage of defunct equipment may be possible on an ad hoc basis for some time, but 
56

overarching policies could become beneficial with increasing numbers of missions. Several SMEs 

have expressed concerns over the “debris field” that will accumulate over time. Inactive assets, 

especially if in an area of interest, could unintentionally create challenges to overcome. This 

includes not just surface assets, but also orbital elements that could intentionally impact the 

surface. Even short-term ad hoc efforts could create negative precedents, so early adoption of 

policy tools should be considered. Regardless, these tools will have to evolve in step with the 

evolution of lunar operations. 

There may be benefits to implementing some of these measures earlier than a purely technical 

perspective would deem necessary. For example, the first CLPS mission, planned for later this year, 

is an Astrobotic contract that would transport the Peregrine One lander to Lacus Mortis, a midlatitude location far from any other surface operations. Because this lander will be far from any 

other actors and is in an area we do not anticipate will become crowded over time, we could 

choose not to implement any of the recommendations contained in this report for this mission. A 

similar decision could justifiably be made for many other planned missions. However, these same 

facts mean that policy measures such as safety zones would not actually impose any limitations on 

other actors should we choose to implement them. Just as we use missions such as this to test 

technologies for more challenging destinations such as the lunar South Pole, we could also use 

Peregrine One or similar missions to practice the design and implementation of policy measures 

such as safety zones in a situation that is relatively low stakes in terms of how we impact other 

actors. 

Ultimately, the decision about whether and how to adopt these recommendations is a policy 

choice. As a signatory to the Artemis Accords, the United States has committed to using and 

respecting safety zones and to protecting heritage sites. However, what those commitments mean 

in practice remains to be determined, and the other recommendations contained in this report are 

not commitments the United States has ever made publicly. Each of the recommendations 

contained in this report derives directly from concerns raises by NASA SMEs and respond to specific, 

technical- and science-based challenges. However, these recommendations do present both pros 

and cons, and we are not recommending that every measure be taken for every mission. This report 

is intended to support decisions by policymakers and mission planners, not to dictate those 

decisions. 

Table 15. Implementation: Summary of Options and Rationale. 

Options to Supplement Policy Tools Rationale 

For missions over which NASA has operational control, 

policy decisions should be communicated to relevant 

directorates, offices, and programs within the agency, 

Implementation of policy tools 

varies by NASA’s level of operational 

control—NASA can incorporate 
57

Options to Supplement Policy Tools Rationale 

and processes should be developed to ensure that 

these actors understand and build the appropriate 

policy decisions into their plans.

policy tools as needed for missions it 

more directly controls 

For CLPS missions, and other missions operated as a 

service, NASA should consider working with relevant 

contracting companies to ensure that they build 

NASA-determined policy tools into their mission 

plans.

Implementation of policy tools 

varies by NASA’s level of operational 

control—NASA may have to consider 

policy tools on a case-by-case basis 

to implement desired policy tools 

into contracts for missions where 

NASA has less operational control 
58

Part 4: Summary, Conclusions, and Next Steps 

The Artemis campaign has already begun with the launch of the CAPSTONE lunar orbiter in June of 

this year and the imminent launch of SLS. Robotic surface missions will begin in a matter of months, 

ushering in years of high-cadence, increasingly complex missions to the lunar surface by NASA and 

commercial and international actors.88 In addition to the challenges inherent in lunar exploration, 

this new era raises a number of challenges that require a mix of policy and technical solutions. 

4.1 Summary of Findings, Options, and Recommendations 

Through our conversations with SMEs, we identified seven categories of challenges to lunar 

landings and operations. Each set of challenges can be mitigated by policy measures; this report 

provides (1) policy tools (options and recommendations) to do so, and (2) options to supplement 

policy tools to increase their effectiveness. These are summarized below. 

The measures discussed in this report need not all be implemented simultaneously or for each lunar 

mission. A practical, evidence-based approach to implementation—focusing on what challenges 

particular missions face and what policy tools can best mitigate those challenges—is called for as 

the Artemis campaign continues. 

Policy Tools to Address Challenges to South Polar Landing and Operations 

Landings 

NASA could increase the priority of obtaining PSI measurements when possible. Mission planners 

should look for opportunities for dedicated PSI measurements spanning more missions or obtain 

data by indirect means if that is not possible. Data regarding PSIs should be shared publicly, 

consistent with longstanding NASA practice. 

NASA could focus its investigations into this energy flux [from ejected particles] with the goal of 

identifying standoff distances from landing sites that will reduce the flux to tolerable levels. Mission 

planners could then refrain from landing craft within that distance from other operations taking 

place on the lunar surface. 

NASA SMEs should consider beginning cooperative PSI prediction, measurement, and safety work 

with partner agencies and the private sector with the goal of developing “gold standards” for PSI 

predictions. 

After NASA SMEs begin cooperative work with partners to understand PSI risks, NASA could work 

with those partners to explore the possibility of formal standardization as a long-term goal. 

88 Appendix C 
59

NASA and partners should consider placing a priority on the development of landing and ascent 

infrastructure, such as prepared landing and ascent surfaces, in areas that are likely to experience 

multiple operations in close proximity. 

Surface Operations 

We recommend that for each mission, planners identify and quantify to the extent possible dangers 

posed by: 

• Regolith ejected from the surface as the result of rover travel or other movement 

• Pressure vessels during normal operations, at end of life, and in the event of failure 

• Shadowing caused by tall structures 

• Non-ionizing radiation from all sources 

• Ionizing radiation from all sources 

• Any chemicals released during normal operations or in the event of failure 

• Any other hazards unique to specific hardware or operations (e.g., nuclear power systems) 

• Special hazards posed by the nature of the location or terrain (e.g., significant slopes, boulders, 

dust, surface, or regolith characteristics) 

• Damage to instrumentation (i.e., sensors, seismometers, or other instruments that may be 

damaged due to nearby landings and/or operations)

• Waste disposal 

Policymakers could work with mission planners to (a) identify risks that each element of a mission 

could cause to others using the checklist above, (b) identify risks that other actors might cause to 

our own operations, and (c) identify a radius or other distance around each activity that can 

reasonably minimize (but likely not eliminate) those risks.

The design of safety zones could become a standard element of mission planning. Safety zones 

should be tailored to the specific circumstances of our activities, but also take into account the 

geographical and other features of the target site (e.g., the presence or absence of ridges, boulders, 

etc. that could provide physical protection).

Additional steps, such as the creation of protective berms, landing pads, and siting such objects 

inside craters, could be considered as part of mission planning to minimize the size and need for 

safety zones.

We recommend that NASA and the U.S. Government respect safety zones or similar tools 

established by non-signatories. 

Moving Across the Lunar Surface 

We recommend that mission planners optimize traversable pathways between landing sites and/or 

other sites of interest. Models can be revisited if and especially when more details on rover 
60

capabilities become known. Additionally, the agency could work with international partners whose 

missions may overlap with or benefit from the identification of these pathways. 

The creation and protection of “transit corridors” in the south polar region could be considered. 

NASA could (1) identify these corridors, (2) make their locations publicly known, (3) refrain from 

placing or disposing of equipment or facilities in these corridors (with an exception described in this 

report), and (4) request other space actors to exhibit the same restraint, at least until our 

capabilities advance beyond the need to avoid long periods of darkness. 

If fixed facilities are deployed in areas where mobile assets are likely to operate, we recommend 

that they be provided with visual and radio beacons and their locations made publicly known. In all 

cases, these facilities should be situated so as not to block mobile vehicles, including large, crewed 

rovers, from transiting the area. 

Radio-Frequency Coordination 

We recommend that NASA continue engagement with the interagency and continue to rely on the 

ITU to avoid radio-frequency interference in lunar operations. 

Areas with Special Characteristics 

We recommend efforts be made to ensure freedom of access for all space actors to this region [the 

Connecting Ridge] of the Moon, such as by exercising restraint when hardware is disposed in the 

area and consolidating operations sites when possible while still meeting mission objectives. 

We recommend that NASA work with Artemis partners to jointly support UN space resource efforts 

directed at practical, actionable norms and best practices that support ISRU efforts and sustainable 

operations. 

Unexpected Activities on the Surface 

Mission planners could consider including hardware that would allow them to identify and record 

any unexpected activities in their vicinity. 

Human Heritage Protection 

We recommend that the 2011 Recommendations be continued and implemented for Apollo and 

Surveyor sites, and that their recommendations be implemented in commercial and international 

partnerships as required by law. 

We recommend that NASA work with the Department of State and other relevant U.S. agencies and 

departments to identify which, if any, additional U.S. robotic or human sites warrant heritage 

protection. Because these sites will be indefinitely protected—and thus generally off-limits for 
61

operations—we recommend that NASA exercise extreme restraint in seeking heritage protection 

for future sites, particularly those in potentially crowded areas such as the south polar region. 

We recommend that NASA work with the Department of State to determine whether other nations 

request heritage protection. Any dispute about the appropriateness of such a designation should be 

handled through diplomatic channels; if an internationally agreed upon process ultimately develops 

to identify heritage sites, that process should supplant this informal, diplomatic process. 

NASA could work with interagency experts on terrestrial heritage protections and the Department 

of State to (1) learn best practices for heritage site identification and (2) begin raising this issue in 

appropriate international fora such as COPUOS and potentially UNESCO. 

We recommend applying the recommendations set out in 2011 to heritage sites that are identified 

anywhere on the Moon, including in the polar region. 

We recommend exercising restraint in identifying new heritage sites to minimize criticism and 

increase the likelihood that other actors will adopt similar protective measures. 

Options to Supplement Policy Tools 

Transparency 

We recommend working with the Department of State to convene a meeting of Artemis Accords 

signatories—or a subset of them actively involved in lunar operations—to discuss with them policy 

and related measures that we anticipate using for upcoming lunar missions. 

We recommend a full public relations strategy, as well as multiple streams of multilateral 

engagement, to articulate our justifications for policy measures in order to forestall negative 

reactions and solidify our behavior as a precedent to be followed rather than a threat to the space 

community. 

Coordination 

We recommend working with the Department of State during joint mission planning to ensure that 

our partners share our views regarding the steps necessary to respond to the challenges and 

threats described in this report. 

We recommend that policymakers work with the Department of State, industry, international 

partners, and ultimately the broader space community to develop mechanisms for consultation and 

coordination to deconflict operations on the Moon. 
62

Implementation 

For missions over which NASA has operational control, policy decisions should be communicated to 

relevant directorates, offices, and programs within the agency, and processes should be developed 

to ensure that these actors understand and build the appropriate policy decisions into their plans. 

For CLPS missions, and other missions operated as a service, NASA should consider working with 

relevant contracting companies to ensure that they build NASA-determined policy tools into their 

mission plans. 

4.2 Known Unknowns 

This report is being written before any detailed, on-the-ground exploration of the lunar South Pole 

has taken place. As missions proceed (particularly VIPER and crewed operations), we expect to fill 

major gaps in our knowledge. As we answer these questions, policy tools should be adjusted to fit 

the facts. 

One critical question is whether particularly valuable resource deposits exist in certain locations on 

the lunar surface. Modelling and remote sensing suggest large water ice deposits in certain PSRs, 

but those projections remain untested; even if remote sensing data is accurate, we are unlikely to 

learn which deposits can most easily be accessed and used until we have robotic and/or human 

presence to verify those facts. Early missions may identify particularly valuable or accessible 

resources; if that occurs, policy tools should be tailored to the characteristics of those resources, 

building on the criteria and considerations we have discussed in this report. 

Other questions depend on human behavior. Although numerous lunar missions are planned by 

commercial and international actors, it remains to be seen which of those will occur.89 Of those that 

do occur, we are unaware whether those responsible will consider their missions to be deserving of 

scientific or heritage protection, or, conversely, whether other actors will seek heritage protections 

for their own sites or view certain locations as deserving of special protection that we have not 

considered. 

More generally, the volume of traffic to the Moon and the polar region remains unclear. NASA 

mission planning continues to evolve, as does that of other actors. Policy measures may need to 

become more restrictive if traffic becomes heavy; conversely, technical innovations and additional 

data may allow relaxation of certain restrictions. As we describe in the Implementation section, 

many of these policy measures may not be operationally necessary until multiple actors are 

operating in proximity to each other. 

89 Appendix C 
63

4.3 Revisiting the Recommendations 

The options described in this report—and the issue of policy implications of lunar operations 

generally—should be revisited on an ongoing basis. Additional knowledge will allow betterinformed tools and increasing operations will require different measures than will early, 

intermittent operations. Although many of the options described in this report implement certain 

legal and political commitments, none of these measures are required to be implemented precisely 

as described in this report. NASA, the U.S. Government, and commercial and international partners 

should engage in an ongoing, iterative process of developing and modifying policy tools just as we 

do technologies. 

4.4 Conclusion 

This report should not be the end of this conversation. As the Artemis campaign continues, NASA, 

our partners, and other space actors will gain additional knowledge that should be used to inform 

further development of these and other policy tools. Likewise, the precise nature, scope, and 

cadence of lunar missions remains to be seen; policy measures will likely need to be adapted to 

respond to however crowded the Moon turns out to be, particularly in the south polar region. 

Identification of particularly valuable sites, such as large deposits of volatiles and/or areas of unique 

interest should also shape implementation of these tools. Policymakers, mission planners, the 

scientific community, and the broader international and commercial community should engage on 

these issues in an ongoing, iterative way to see what works, what doesn’t, and what measures are 

most supportive of sustainable operations. 
64

Appendix A: Terms of Reference 

Background 

Technical and scientific criteria provide constraints on the availability of landing and operations 

sites on the surface of the Moon—particularly in the vicinity of the lunar South Pole. In the short 

term (one to five years), NASA plans to launch numerous missions to the lunar South Pole, as do 

multiple other commercial and international actors. With multiple operations occurring 

simultaneously, these activities could interfere with each other and/or create limitations on the 

ability of others to operate. 

In addition to scientific and technical considerations, the choice of landing and operations sites near 

the lunar South Pole raise a range of other considerations. Because of the relatively small number 

of useful landing sites that meet particular mission objectives (i.e., those meeting desired technical 

and scientific criteria), polar sites are a limited resource. Space actors that occupy and utilize these 

sites could, at least to some extent, displace other actors from those same sites. 

NASA may wish to take technical and policy considerations into account in the selection of landing 

and operations sites in order to, e.g. (1) protect the safety of U.S. Government operations, (2) 

secure freedom of action for U.S. interests, (3) minimize negative political, international, and public 

perception repercussions of site choices, and (4) establish and promote international standards. The 

choice of landing and operations sites, as well our publicly articulated views surrounding those 

choices, could create a precedent that guides future human exploration of the Moon and other 

celestial bodies, including Mars and asteroids. 

Scientific and technical criteria significantly limit the areas of the lunar surface that could serve as 

landing and operation sites for U.S. robotic and crewed activities, especially in the vicinity of the 

South Pole. Particularly important criteria include: persistent line-of-sight to Earth, the nearby 

presence of permanently shadowed regions (PSRs) that might contain water ice deposits, and the 

availability of sunlight throughout mission durations. With regard to south polar destinations, 

ninety-three potential landing sites were identified by NASA directorates and shown to meet these 

criteria, spread across seven polar regions. Of these, only a very small number are reachable at each 

mission availability date. Other space actors, such as foreign and commercial actors, are likely to be 

faced with similar constraints, and therefore likely to focus on many of the same potential sites as 

NASA. The United States and these other actors may choose to establish safety zones and utilize 

other policy mechanisms to protect operations in these areas. 

Existing international law and norms of behavior provide some guidance. The 1967 Outer Space 

Treaty provides for freedom of access to all areas of celestial bodies. The Treaty also requires states 

to give “due regard to the corresponding interests” of other states operating in space. Finally, the 
65

Treaty requires consultations prior to any activities that might create “harmful interference” in the 

activities of others in space. 

The United States and partner nations have built on our Outer Space Treaty obligations with the 

Artemis Accords, which contain more detailed commitments relating to civil exploration activities. 

Section 11 of the Accords sets out detailed rules for deconflicting operations amongst space actors. 

The United States has publicly committed to implementing these rules in our exploration plans. 

Most importantly, we have committed to (1) refrain from creating harmful interference in the 

activities of other Signatories and (2) publicly establish “safety zones” around our operations. These 

zones must be based on publicly articulable needs and must change or terminate as our operations 

evolve. The Accords state: “The size and scope of [a] safety zone...should reflect the nature of the 

operations being conducted and the environment that such operations are conducted in; The size 

and scope of [a] safety zone should be determined in a reasonable manner leveraging commonly 

accepted scientific and engineering principles.” Although we cannot lawfully exclude other actors 

from areas of the surface, the Accords provide for consultations before any other signatory enters a 

declared safety zone. With regard to non-signatories of the Accords, the U.S. Government takes the 

position that the Outer Space Treaty nevertheless requires some form of coordination prior to 

operating in the vicinity of previous arrivals to a celestial body. 

Legal, policy, and technical issues relating to the protection of human heritage in outer space also 

provide useful guidance, particularly with regard to the issue of safety zones. This project will draw 

from internal NASA guidance relating to the protection of Apollo sites, the recent One Small Step 

Act, and international efforts to identify and protect heritage in space. 

Goals and Study Questions 

This study aims to answer two related questions: (1) what technical and policy considerations 

should NASA take into account in the selection of lunar landing and operations sites and (2) what 

technical and policy considerations should NASA take into account when implementing tools such 

as safety zones in order to protect these operations and U.S. interests? 

Although this project will consider a wide range of technical and policy considerations, two issues 

will receive particular focus: the selection of landing and operations sites and the establishment of 

safety zones around these locations. Put another way, the core of this project is to help answer the 

questions: where should NASA operate, and how can we protect those operations? 

Scope of Work and Proposed Approach

The scope of this project is limited to recommendations regarding NASA and NASA-sponsored 

crewed and robotic activities on or around the lunar South Pole, and is limited to relatively earlystage operations, up to the establishment of a persistent human presence.2 The Commercial Lunar 

Payload Services (CLPS) initiative, Human Landing System (HLS) program, and as-yet-finalized 
66

missions will be covered by this scope, so long as they are by, or for, NASA. Activities by purely 

private sector actors will not be the subject of these recommendations. 

Although this project will place special emphasis on operations in the vicinity of the lunar South 

Pole because scarcity and interference issues are likely to first arise there, the considerations 

relevant to this inquiry, and the guidance and recommendations that will be developed, will also be 

helpful in shaping NASA operations in other locations. Although physical differences in celestial 

bodies will necessarily result in operational differences, the interests, goals, risks, benefits 

identified, and the recommendations developed here will pave the way to answering these same 

questions on Mars, in the asteroid belt, and elsewhere. 

This project will be conducted in such a way as to develop guidance and recommendations that will 

lead to publicly defensible operational choices, such as the selection of specific sites on the surface 

of the Moon and the establishment of safety zones to protect them. The project will begin with a 

series of meetings with NASA lunar program experts in order to develop a detailed baseline of what 

is possible and desirable from a programmatic perspective, as well as an understanding of what 

technical criteria should be used to implement tools such as safety zones. The second phase of the 

project will be meetings with counterpart space agencies with whom NASA anticipates possible 

cooperation in lunar missions in order to seek expert-level input on considerations relevant to the 

goals of the study. OTPS will then develop initial draft guidance and recommendations. 

Phase three of the project will be to share the core elements of the guidance and recommendations 

with outside reviewers, representing a wide range of backgrounds, in order to receive their 

individual views regarding any problems or omissions with that guidance. Outside experts are 

expected to include: academic space law and policy experts from Japan, the Netherlands, and the 

United Kingdom; industry representatives from companies with plans for lunar activities; an 

academic from the United States focusing on lunar surface operations; members of the intelligence 

community with expertise in space; and representatives of civil society organizations. 

Ultimately, guidance and recommendations that survive scrutiny will be compiled into a report by 

OTPS. This report will include specific case studies, drawn from currently planned and anticipated 

operations, in order to demonstrate how guidance and recommendations could be implemented. 

Intended Outcomes

Answering these overarching questions will provide guidance to NASA when faced with specific 

questions such as how many polar sites to operate simultaneously, whether they should give 

greater priority to geographically strategic sites, whether and when they should defer to other 

space actors in accessing certain locations, and when and how to implement safety zones. 
67

The project team will work discreetly with international partner space agencies, and international 

and interdisciplinary experts to provide specific, actionable guidance and recommendations to lunar 

program managers and NASA leadership. 

Deliverables 

This study will deliver a brief paper with policy options, their pros and cons, rationale for 

recommendation, and effects of implementing the guidance and recommendations. 

Intended Distribution and Access

The final report is intended to be accessed by OTPS, the Office of the Deputy Administrator, and 

other stakeholder offices or programs as identified by OTPS and the Office of the Deputy 

Administrator. 

Pending final review by relevant directorates, NASA leadership, and the interagency, a summary of 

the guidance and recommendations, or decisions that derive from it, could be made available 

publicly. Decisions about public release and communications strategies should be made only after 

project completion. 
68

Appendix B: List of Those Consulted 

Phase I: Internal Discussions (NASA Lunar Program Leads/Points of 

Contact and SMEs) 

• CASSA - overview 

• CASSA - lighting conditions 

• CASSA - mission availability 

• CASSA - site planning and governance 

• CASSA - engagement strategy 

• CASSA - hazards and mitigations list review 

• Agency-level architecture 

• HLS perspective 

• CLPS perspective 

• VIPER and instrument perspective 

• Entry, Descent, and Landing (plume-surface interactions) 

• PSI modeling and environments 

• OIIR - International Programs 

Phase II: External Discussions (Space Agencies) 

• United Kingdom Space Agency (UKSA) 

• European Space Agency (ESA) 

• German Aerospace Center (DLR) 

• Luxembourg Space Agency (LSA) 

• Italian Space Agency (ASI) 

• Japan Aerospace Exploration Agency (JAXA) 

• Australian Space Agency (ASA) 

Phase III: External Reviews (Cross-Disciplinary Experts) 

• China Aerospace Studies Institute 

• For All Moonkind 

• International Institute of Air & Space Law, Leiden Law School, The Netherlands 

• Open University 

• Secure World Foundation 

• University of Central Florida 
69

Appendix C: List of Near-Term Lunar Missions 

Anticipated Lunar Surface Missions in the Near-Term (2022-2026)

*South Pole/South Polar Region landing and/or operations 

Note that launch dates may change and additional missions may arise within this timeframe. 

Country Organization Mission Launch 

U.S. NASA CLPS Task Order 2 (Intuitive Machines)† 2022 

U.S. NASA CLPS Task Order 2 (Astrobotic) † 2022 

Japan JAXA Smart Lander for Investigating the Moon (SLIM)90 2022 

Japan ispace Hakuto-R Mission 191 2022 

India ISRO Chandrayaan-392 2022 

Russia Roscosmos Luna-2593 2022* 

U.S. NASA CLPS Task Order PRIME-1 (Intuitive Machines) † 2023* 

U.S. NASA CLPS Task Order 19C (Masten Space Systems) † 2023* 

India ISRO 

Lunar Polar Exploration (LUPEX), joint JAXA mission, ISRO 

lander94,

95 2023* 

U.S. NASA CLPS Task Order 19D (Firefly Aerospace) † 2024 

U.S. NASA CLPS Task Order 20A VIPER (Astrobotic) † 2024* 

90 “International Space Exploration,” JAXA, accessed June 17, 2022,

https://www.exploration.jaxa.jp/e/program/#lunar. 

91 “Project,” ispace, accessed June 17, 2022, https://ispace-inc.com/project/. 

92 “India targets August launch for Chandrayaan-3 lunar lander,” SpaceNews, last modified February 3, 2022, 

https://spacenews.com/india-targets-august-launch-for-chandrayaan-3-lunar-lander/. 

93 “Russia aims to rekindle moon program with lunar lander launch this July,” Science and Astronomy, Space, last 

modified February 11, 2022, https://www.space.com/russia-rekindle-moon-program-luna-25-launch. 

94 “Global Exploration Roadmap,” International Space Exploration Coordination Group, last updated August 2020, 

https://www.exploration.jaxa.jp/e/program/#lunar 

95 “International Space Exploration,” JAXA, accessed June 17, 2022, 

https://www.exploration.jaxa.jp/e/program/#lunar. 
70

Country Organization Mission Launch 

U.S. NASA CLPS Task Order CP-11 (Intuitive Machines) † 2024 

U.S. NASA NextSTEP-2 App. H Option A: Uncrewed Demo (SpaceX)96 2024* 

Japan ispace Hakuto-R Mission 297 2024 

China CNSA Chang’e 698 2024* 

China CNSA Chang’e 799 2024* 

Israel SpaceIL Beresheet2100,

101 2024 

U.S. NASA CLPS Task Order CP-12 (RFP in progress) † 2025 

U.S. NASA 

NextSTEP-2 App. H Option A: Artemis III Crewed Demo 

(SpaceX)102 2025*103

Russia Roscosmos Luna-27104 2025* 

U.S. NASA CLPS Task Order CP-21 (Announced) † 2026 

U.S. NASA CLPS Task Order CP-22 (Announced) † 2026* 

96 “Report regarding NASA Human Landing System Program,” Explanatory Statement accompanying FY 2022 

Consolidated Appropriations Act (P.L. 117-103), NASA, last modified April 2022, 

https://www.nasa.gov/sites/default/files/atoms/files/hls_30_day_report_final_041922.pdf. 

97 “Project,” ispace, accessed June 17, 2022, https://ispace-inc.com/project/. 

98 “Future Chinese Lunar Missions,” Goddard Space Flight Center, NASA, last modified September 3, 2021, 

https://nssdc.gsfc.nasa.gov/planetary/lunar/cnsa_moon_future.html. 

99 “Future Chinese Lunar Missions,” Goddard Space Flight Center, NASA, last modified September 3, 2021, 

https://nssdc.gsfc.nasa.gov/planetary/lunar/cnsa_moon_future.html. 

100 “Moon Lander,” Science and Research, Israel Aerospace Industries, accessed June 17, 2022, 

https://www.iai.co.il/p/moon-lander. 

101 Israel, UAE to collaborate on Beresheet 2 moon mission,” Middle East, The Jerusalem Post, last modified April 

30, 2022, https://www.jpost.com/middle-east/article-705511. 

102 “As Artemis Moves Forward, NASA Picks SpaceX to Land Next Americans on Moon,” Moon to Mars, NASA, last 

modified April 22, 2021, https://www.nasa.gov/press-release/as-artemis-moves-forward-nasa-picks-spacex-toland-next-americans-on-moon. 

103 “NASA Provides Update to Astronaut Moon Lander Plans Under Artemis,” Moon to Mars, NASA, last modified 

March 23, 2022, https://www.nasa.gov/press-release/nasa-provides-update-to-astronaut-moon-lander-plansunder-artemis. 

104 Luna 27,” Wikipedia, accessed June 17, 2022, https://en.wikipedia.org/wiki/Luna_27.
71

†CLPS mission status presented at the Lunar and Planetary Science Conference in March 2022. 

(Note that PRIME-1, Task Order 19D, Task Order 20A, Task Order CP-12, Task Order CP-21, and Task 

Order CP-22 have been updated to reflect changes from March 2022 to July 2022.)105 

105 P. B. Niles, “SUMMARY OF THE CONTRACTED DELIVERIES OF NASA PAYLOADS TO THE MOON VIA COMMERCIAL 

LUNAR PAYLOAD SERVICES (CLPS),” 53rd Lunar and Planetary Science Conference (2022): 

https://www.hou.usra.edu/meetings/lpsc2022/pdf/2791.pdf. 
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Appendix D: Beyond this Project 

A Note Regarding Mars

This report focuses on lunar operations because those portions of the Artemis campaign are most 

well-defined and soonest in time. However, operations on other celestial bodies, such as Mars, raise 

the same policy challenges as do those on the Moon. The physical characteristics of the Moon and 

Mars are different in ways that can—and should—affect the details of policy solutions to Mars 

operations. For example, the presence of an atmosphere on Mars limits travel of debris ejected by 

landing operations, as does Mars’ higher gravity, but that same atmosphere increases the likelihood 

of cratering by PSIs. Furthermore, Mars is subject to far stricter planetary protection protocols than 

is the Moon, and those requirements will need to be incorporated into Martian mission planning. 

Nevertheless, the policy tools described here are suitable for application on Mars, with 

modifications to suit the characteristics of that planet. As mission plans for Martian operations 

evolve, questions of policy should be included at each stage of planning and implementation. 

Equity and Ethics

Exploration of the Moon and the solar system raises more issues than can be addressed in this 

report. This report attempts to answer those questions posed by SMD and the Office of the 

Administrator; those questions are largely technical, scientific, and operational. However, 

exploration of the Moon—particularly when it involves commercial activities and the possibility of 

human habitation—also raises issues of ethics and equity. As with any new endeavor, there is a 

chance that our exploration will interact in complicated ways with human concerns, such as 

unequal access to resources, geopolitical power dynamics, cultural values, and more. Some of the 

recommendations contained in this report may have implications for these questions as well.106

These issues deserve focused attention, and we note that OTPS has ongoing work on social and 

ethical considerations in other projects, namely, how NASA should operationally consider long-term 

societal and ethical implications of Artemis. This work can ultimate help support NASA’s vision for 

sustainable and responsible exploration, as robust and transparent ethical dialog helps enable longterm shared visions and public benefit. 

106 None of the recommendations in this report are exclusive to NASA missions. Although this report is intended to 

guide NASA planning, NASA and the U.S. Government should be willing to respect the same or similar measures 

taken by other space actors. In that sense, these recommendations are “neutral,” but even facially neutral 

measures can have the effect of amplifying existing inequalities or other features of the status quo. 
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Appendix E: Acronyms 

Acronym Definition 

ASA Australian Space Agency 

ASI Italian Space Agency 

CASSA Cross-Artemis Site Selection Analysis 

CLPS Commercial Lunar Payload Services 

CNSA China National Space Administration 

COPUOS Committee on the Peaceful Uses of Outer Space 

DLR German Aerospace Center 

EL3 European Large Logistics Lander 

ESA European Space Agency 

ESDMD Exploration Systems Development Mission Directorate 

EVA Extravehicular Activity 

FCC Federal Communications Commission 

GEO geosynchronous orbit 

HLS Human Landing System 

HSM Human Surface Mobility 

ISECG International Space Exploration Coordination Group 

ISO International Organization for Standardization 

ISRO Indian Space Research Organization 

ISRU in-situ resource utilization 
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Acronym Definition 

ISS International Space Station 

ITAR International Traffic in Arms Regulations 

ITU International Telecommunication Union 

JAXA Japan Aerospace Exploration Agency 

LSA Luxembourg Space Agency 

LSITP Lunar Surface Instruments and Technology Payloads 

LUPEX Lunar Polar Exploration 

NASA National Aeronautics and Space Administration 

NTIA National Telecommunications and Information Administration 

OIIR Office of International and Interagency Relations 

OTPS Office of Technology, Policy, and Strategy 

PSI plume-surface interaction 

PSR permanently shadowed region 

RFI radio-frequency interference 

RFP request for proposals 

SCALPSS Stereo Cameras for Lunar Plume-Surface Studies 

SLIM Smart Lander for Investigating the Moon 

SLS Space Launch System 

SMD Science Mission Directorate 

SME subject matter expert 

STMD Space Technology Mission Directorate 
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Acronym Definition 

TOR Terms of Reference 

UKSA United Kingdom Space Agency 

UN United Nations 

UNCOPUOS United Nations Committee on the Peaceful Uses of Outer Space 

UNESCO United Nations Educational, Scientific and Cultural Organization 

VIPER Volatiles Investigating Polar Exploration Rover