Communications and Navigation Needs for the Foundational Exploration Segment (ACR25 white paper)¶

Document: Communications and Navigation Needs for the Foundational Exploration Segment, an eight-page white paper headed "2025 Moon to Mars Architecture" and footed "2025 Moon to Mars Architecture Concept Review". No date is printed; the file name ends in v2. It is NTRS citation 20250010953. Files: text sources/text/docs/ntrs-20250010953-ACR25-WP-FE-CPNT-v2.txt; raw sources/raw/docs/ntrs-20250010953-ACR25-WP-FE-CPNT-v2.pdf (fetched 2026-10-01T07:22:47Z from https://ntrs.nasa.gov/api/citations/20250010953/downloads/ACR25%20-%20WP%20-%20FE%20CPNT%20v2.pdf, per sources/manifest.csv). Page numbers: the printed page numbers (1–8) match the PDF pages and the text file's [page N] markers. Pages 1–7 were checked against the PDF; p. 8 is references only.

Which paper this is. NASA's White Papers web page lists it under "2025 Architecture Concept Review", with the same title and NTRS link (White Papers page, fetched 2026-10-01). The 2025 Architecture Update (Dec 2025) lists it as "Communications and Navigation Needs for Foundational Exploration": "how NASA's communications and navigation needs will expand beyond those of initial Artemis missions as it explores more of the lunar surface" (Update, p. 17).

Summary. How the C&PNT sub-architecture must grow from the Human Lunar Return segment through Foundational Exploration, as more users, longer missions and more of the South Pole region come in. Surface elements act as hubs for other users, and surface relays may be added "much like a terrestrial cell tower" (p. 2). The paper covers interoperability standards (LunaNet and its frequency plan, 3GPP and 802.11 Wi-Fi on the surface), four user-demand characteristics (connectivity, coverage, capacity, PNT accuracy) with notional growth charts, a real-time navigation need of 25–50 m, and technologies under development. Mars appears as a reason to test at the Moon.

The content is on C&PNT Systems, with the network points on SCaN Networks.

Contents¶

Page	Section	Wiki home
1	Introduction; Key Challenges	C&PNT Systems
2	Architecture Considerations (hubs, surface relays); Interoperability Considerations (standards, LunaNet frequency plan); User Demand Considerations	same
3	Table One, four user-demand characteristics; Figure One, the C&PNT sub-architecture diagram	same; SCaN Networks
4	Connectivity; Coverage; Capacity; PNT Accuracy	same
5	Three notional charts: links, throughput, throughput by sub-architecture	same
6	Technology Development Considerations; Conclusion	same
7	Key Takeaways	this page
8	References 1–14	this page

What the PDF shows that the text layer loses¶

Table One (p. 3) pairs an icon and a heading with each definition. The text layer gives the four headings, then the four definitions, in matching order.
Figure One (p. 3), "Diagram illustrating the C&PNT sub-architecture for the Foundational Exploration segment", is printed sideways and has no text in the text layer. Its title is "Communications and Position, Navigation, and Timing Links for the Foundational Exploration Segment". Its labels match, one for one, those the wiki recorded from ADD Rev C's p. 67 figure:
- the relays "International Partner Relays", "Lunar Communications Relay and Navigation Systems (LCRNS)*" and "Gateway"
- the "Ground Stations" list: "Deep Space Network", "Near Space Network", "ESA Sites", "HLS Providers", "LCRNS Providers*", "International Providers"
- "Each ground asset has lunar visibility a third of the Earth's daily rotation. Additional ground assets are needed for backup and resiliency."
- the note on broadcast PNT within the service volume, and the footnote "*The Near Space Network integrates LCRNS provider services for missions."
That it is the same figure is the wiki's reading, from the labels (SCaN Networks). Like the ADD's, it still shows Gateway as a relay (open question 22).
The three charts on p. 5 have no text in the text layer beyond their captions. All are headed "Foundational Exploration Segment" and plot "Early", "Mid" and "Late" Foundational Exploration, except the third, which plots sub-architectures:
- "Anticipated Growth in Number of Links": "Total User Links" and "Priority Links (i.e., crew-critical links)". Axis 0 to 60.
- "Anticipated Cumulative Data Throughput (Mbps)": "Total User Data" and "Priority Data (i.e., crew-critical data)". Axis 0 to 1100. The caption says the "confidence bars at the top indicate an expected range of throughput".
- "Anticipated Maximum Data Throughput by Sub-Architecture": "Transportation (e.g., landers)", "Mobility (e.g., rovers)", "Habitation (e.g., habitats)" and "Utilization (e.g., science)". Axis 0 to 1100. Habitation's bar is the tallest, as the text says (p. 4).
The captions call all three "notional". The wiki reads no values off them.

Key takeaways (p. 7)¶

"As NASA's Moon to Mars Architecture progresses into the Foundational Exploration segment, the Communications and Positioning, Navigation, and Timing sub-architecture must evolve and scale to support a growing number of users and increasingly ambitious crewed missions."
"Interoperability is key to realizing a multi-partner network robust to the needs of all lunar users. NASA must work with commercial and international partners to establish and implement standards for service interfaces, spectrum allocations, networking protocols, and more."
"The increase in user demand requires the Communications and Positioning, Navigation, and Timing sub-architecture to evolve to offer extended availability, greater throughput, improved accuracy, and enhanced services. User demand considerations include connectivity, coverage, capacity, and accuracy."
"As the Foundational Exploration segment progresses, integrating new services and technologies like laser communications, delay-tolerant networking, and lunar-equivalent GPS could meet additional user needs, demonstrate new technologies, and prove Mars-forward capabilities."

Compared with ADD Rev C and the gap spreadsheet¶

This comparison is the wiki's:

Builds on the ADD's element section. The paper points to the ADD for the growth of the relay service volume (p. 4). The ADD's SCaN section gives it: from 80° S and 125 km altitude in Human Lunar Return toward 75° S and 200 km (ADD Rev C, p. 66; SCaN Networks).
Surface standards. The paper says "NASA plans to use Third Generation Partnership Project (3GPP) cellular and 802.11 Wi-Fi standards" on the lunar surface (p. 2). The completed definition task LD-103 adopted "a combination of Space-to-Space Communications Systems, WiFi 6, and 3GPP (5G)" (ADD Rev C, p. 75). The paper doesn't cite LD-103 or any definition task (search of its text), and doesn't mention Space-to-Space Communications Systems. See Key definition tasks.
Gap titles in neither list. The paper names three "architecture-driven technology gaps" as examples: "Position, Navigation, and Timing (PNT) for In-Orbit and Surface Applications, High Rate Comm Across the Lunar Surface, and High-Rate Deep Space Comm" (p. 6). Its reference for the gaps is the 2024 white paper (reference 11). None is a title in the Dec 2025 spreadsheet. By subject they look like #0101, #0103 and #0102; the match is the wiki's. The 2024 white paper prints only five gap titles. Its surface-communications title is "High-bandwidth, High-reliability Surface-to-Surface Communications", the same as #0103's in Dec 2025, not "High Rate Comm Across the Lunar Surface". It prints no PNT or deep-space title. So the paper's three titles aren't the 2024 paper's either, as far as that paper shows (open question 35).
PNT accuracy. The paper's early Foundational Exploration need is "a real-time absolute accuracy of 25-50 meters", and "NASA has procured systems to realize 10-meter or better accuracy, which offers margin for future missions" (p. 4). Gap #0101's target is absolute real-time localization "to within 10m, 3 sigma" (tech gaps spreadsheet, ESDMD #0101). The paper gives no sigma level and doesn't name the procured systems.
Mars communications disruption. The paper doesn't discuss MD-12, "Maximum Allowable Crewed Communications Disruption". For Mars it points to a 2023 white paper, "Mars Communications Disruption and Delay" (p. 6, reference 12).

References that are other architecture documents¶

The paper cites 14 references (p. 8). Those that are Moon to Mars documents, as printed:

Ref.	Title, as printed	Among the wiki's sources?
1	NASA's Moon to Mars Objectives	yes, Moon to Mars Objectives (2022) (same file name in the link)
2	NASA's Moon to Mars Architecture	yes, source page
3	NASA's Architecture Definition Document	the ADD documents web page, source page; the ADD itself is ADD Rev C
4	NASA's Lunar Communications and Navigation Architecture, 2023 Moon to Mars Architecture White Paper	no
5	LunaNet Interoperability Specification Document – Version 5	no
6	International Communication System Interoperability Standard	no
11	Architecture-Driven Technology Gaps, 2024 Moon to Mars Architecture White Paper	yes, source page
12	Mars Communications Disruption and Delay, 2023 Moon to Mars Architecture White Paper	no

The others are 3GPP, IEEE Wi-Fi, the Space Frequency Coordination Group, the Interagency Operations Advisory Group, and NASA's laser communications and DTN pages. "No" means no file in sources/manifest.csv or sources/text/pages/ has a matching name; the check is the wiki's (open question 30).

Oddities¶

Two "Figure One"s. The p. 3 diagram and the first p. 5 chart are both captioned "Figure One" (PDF checked). The text refers to "Figure two" and "Figure three" on p. 4 but never to the links chart.
LCRNS's name. "Lunar Communications Relay Navigations Systems" (p. 2) against "Lunar Communications Relay and Navigation Systems (LCRNS)" in the p. 3 figure and the ADD (p. 64).
Two spellings of one standard. The paper's "International Communication System Interoperability Standard" (p. 2) matches one of the ADD's two spellings (SCaN Networks).
As printed: "as the NASA's Moon to Mars Architecture progresses" (p. 1); "engaging in partnered actives" (p. 6); "(e.g., … High-Rate Deep Space Comm), Others will arise" (p. 6).

C&PNT Systems · SCaN Networks · #0101 · #0103 · #0102 · Lunar Terrain Vehicle · Pressurized Rover · RT-7 Interoperability · Foundational Exploration · 2025 Architecture Update