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Space Communications and Navigation (SCaN) Networks

Summary. NASA's communications and PNT services, through two networks: the Near Space Network (NSN), out to two million kilometers, and the Deep Space Network (DSN). They combine government, commercial and international assets (ADD Rev C, p. 64). At the Moon the key project is LCRNS, which validates commercial lunar relay services; its service volume grows from 80Β° S and 125 km altitude in Human Lunar Return to 75Β° S and 200 km. The element is the only one in C&PNT Systems, and its four-page section (pp. 64–67) is the ADD's fullest account of lunar communications, interoperability (LunaNet) and lunar time.

All page numbers are ADD Rev C unless noted.

NASA's description

"NASA's Space Communications and Navigation (SCaN) program provides communications, positioning, navigation, and timing services to missions through two subnets: the Near Space Network (NSN) and the Deep Space Network (DSN). These networks include direct-with-Earth, space relay, and surface assets and services offered through government, commercial, and international providers. The networks also comprise efforts to augment or improve those assets and services.

The NSN provides services out to two million kilometers from Earth through commercial and government ground stations globally and cislunar space relays. The NSN Lunar Communications Relay and Navigation Systems (LCRNS) project validates commercial lunar relay services procured to support the Moon to Mars Architecture. The NSN, through the Commercial Services contract, is contracting with commercial service providers to establish communication and PNT services that will be able to support cislunar users. The DSN comprises an array of ground stations featuring large diameter antennas capable of supporting missions throughout the solar system and beyond, including at the Moon and Mars. The DSN also supports the Mars Communications Relay Network, currently used to relay data from Mars surface missions back to Earth.

Note: NASA decomposes the functional mappings for this integrated element into functions generally provided by the networks, and those specifically provided by LCRNS. For more detail about the evolution of communications and PNT services, see Section 2.2.2 for the C&PNT sub-architecture." (p. 64)

"Integrated element" is a glossary term: "A portfolio that comprises multiple individual assets and provides a suite of integrated capabilities, offering flexible, evolvable concepts to achieve NASA's Moon to Mars Objectives" (p. 298). This one-pager is the only place the wiki's search of the ADD body finds the phrase (Glossary).

Section 2.2 has no numbered subsections (contents, p. 5), so "Section 2.2.2" doesn't resolve. The C&PNT description is on p. 41 (C&PNT Systems; open question 21).

At a glance

From the element one-pager (p. 64).
ADD section 2.3.14 (pp. 64–67)
Implementing program Space Communications and Navigation Program; printed beneath: Space Operations Mission Directorate
Functional mappings Appendix B, B.3.14, split between network functions and LCRNS functions (p. 64)
Segments Human Lunar Return, Foundational Exploration
Sub-architecture C&PNT Systems
Header image "A concept image of lunar relay satellites transmitting data to the lunar surface"

Network partners (2.3.14.1)

"NASA provides network services through distributed assets operated by NASA, international partners, and commercial service providers. Two agency-managed networks β€” the Near Space Network and Deep Space Network β€” integrate these assets and the distributed teams that support them into a suite of capabilities for lunar users" (p. 65).

  • Near Space Network: "geographically distributed ground stations and space relay assets operated by NASA and government, industry, and international partners. The network engages new and existing partners to realize a suite of new capabilities for cis-lunar and lunar surface communications and PNT" (p. 65).
  • Deep Space Network: "three facilities around the globe, approximately 120 degrees apart in longitude" (p. 65).

Interoperability considerations (2.3.14.2)

"NASA seeks to empower network users with a long-term, scalable, and interoperable C&PNT architecture" (p. 65). The standards and frameworks named (pp. 65–66):

Name What the ADD says
LunaNet "an internationally coordinated framework for lunar C&PNT service interoperability extensible to Mars and beyond. It envisions a set of cooperating networks providing C&PNT services to users in transit to, around, and on the Moon."
LunaNet Interoperability Specification "a structure of mutually agreed-upon standards, protocols, and interface requirements to realize this vision"
International Communications System Interoperability Standard "adopted into the architecture during the 2024 Architecture Concept Review β€” enables collaborative operations for the user community". But "industry standards that deviate from International Communications System Interoperability Standard protocols may be implemented if the result is a more robust, industry-proven telecommunications approach."
Spectrum plans Developed with the International Telecommunications Union and the Space Frequency Coordination Group, documented in the International Communication System Interoperability Standard. Implementation support comes from the Consultative Committee for Space Data Systems and the two interoperability standards.

Reference systems and time. "Reference systems and time are fundamental to safe navigation, precision science, communications systems, and interoperability at the Moon. NASA must define, adopt, and implement lunar reference systems (including reference frames) in the early stages of architecture development. As at Earth, individual nations implement international standards, so close coordination is essential" (p. 65). "U.S. policy on these topics is available and international coordination is underway" (p. 66). The footnotes link two files on the White House archive site, "Celestial-Time-Standardization-Policy.pdf" and "Lunar-Reference-System-Policy.pdf"; the IAU's "2024 Resolutions II and III"; and, for "lunar reference frame considerations", "the associated 2024 Moon to Mars Architecture white paper" (p. 66, footnotes 18–21). That white paper is "Lunar Reference Frames" (2024). It compares the Mean Earth and Principal Axis frames and reports a 2024 working group's endorsement of Mean Earth "as the standard for initial surface operations" (paper, p. 3). Rev C itself names no frame; see C&PNT Systems.

The ADD spells the standard both "International Communications System Interoperability Standard" and "International Communication System Interoperability Standard(s)" on p. 65. Both are quoted as printed.

Network evolution (2.3.14.3)

"NASA's networks continuously evolve to meet the needs of future users. For the architecture, this means phased implementation of new services and capabilities that expand connectivity, network access and timeliness, and accuracy in transit to, around, and on the Moon and Mars" (p. 66).

LCRNS service by segment

Human Lunar Return Toward Foundational Exploration
Service volume "from 80Β° S to the South Pole of the Moon and up to 125 km altitude" "75Β° S and up to 200 km"
Links "One bidirectional S-band link, one simultaneous Ka-band return link, and a broadcast Augmented Forward Signal" "two bidirectional, simultaneous S-band and Ka-band links, as well as multiple Augmented Forward Signal links"

From p. 66. In Human Lunar Return, "lunar users rely on C&PNT services provided through a combination of assets at Earth, in lunar orbit, and demonstrations of systems on the lunar surface. Operationally, this will include direct-with-Earth communications and space relay services provided through LCRNS" (p. 66).

Surface communications and PNT

  • Surface-to-surface: "may initially rely on legacy systems (e.g., ultra-high frequency and WiFi) during the Human Lunar Return segment. However, NASA is leveraging terrestrial standards (e.g., 3GPP/5G) to increase mobility, positioning, and system capacity by the early Foundational Exploration segment" (p. 67).
  • PNT: "direct-with-Earth and space relay assets as providers of radionavigation sources. User-side capabilities include onboard sensors and systems that collect, process, and filter navigation data. These can include optical sensors (e.g., cameras, light detection and ranging (lidar) payloads), solar compasses, and inertial measurements units" (p. 67).

Foundational Exploration (2.3.14.3.2)

C&PNT capabilities expand, "offering greater coverage, availability, accuracy, and system capacity". "The number of surface users and data volume increase", and "the deployment of telerobotic and autonomous elements increases demand for both data transfer and navigation data". "New surface wireless networking infrastructure enables direct communication between lunar surface assets and aggregation of data for backhaul transmission to Earth", and offers "supplemental positioning, navigation, and timing data to surface users dependent on a synchronized network". "Through LCRNS, orbital relay capabilities grow at the lunar South Pole and to other regions of interest. Lunar relay services also improve accurate navigation and expand over the global lunar surface volume" (p. 67).

The figure on p. 67

"C&PNT Sub-Architecture for the Foundational Exploration Segment", titled "Communications and Position, Navigation, and Timing Links for the Foundational Exploration Segment". It doesn't extract as text and was read from the PDF; the print is small, so only clearly legible labels are given.

  • Left: the Moon, with surface assets linked to relays in lunar orbit.
  • Middle, the relays: "International Partner Relays", "Lunar Communications Relay and Navigation Systems (LCRNS)*" and "Gateway".
  • Right: a column of "Ground Stations": "Deep Space Network", "Near Space Network", "ESA Sites", "HLS Providers", "LCRNS Providers*", "International Providers". Beside it: "Each ground asset has lunar visibility a third of the Earth's daily rotation. Additional ground assets are needed for backup and resiliency."
  • Link types: direct-with-Earth links for assets, elements, LCRNS, Gateway and international partner relays; relay cross links; asset and element relay links; "Aggregate Links from Surface".
  • Note: "Within the service volume, orbital relays provide broadcast position, navigation, and timing services; alerts; and meet the coverage and availability needs of users in the lunar South Pole region."
  • Footnote: "*The Near Space Network integrates LCRNS provider services for missions."

The figure still shows Gateway as a relay with its own direct-to-Earth link. On Gateway since Rev C, see Gateway.

The ACR25 C&PNT white paper prints the same diagram as its Figure One, captioned "Diagram illustrating the C&PNT sub-architecture for the Foundational Exploration segment" (C&PNT white paper, p. 3). Every label listed above appears on it, Gateway included. That it is the same figure is the wiki's reading, from the labels.

The ACR25 C&PNT white paper

The white paper "Communications and Navigation Needs for the Foundational Exploration Segment" is about the C&PNT sub-architecture as a whole; its content is on C&PNT Systems. What it says about the networks and their program (page numbers are the paper's):

  • Relays. Later in Foundational Exploration, surface relays could talk "direct with ground stations on Earth or through orbital relay elements already instantiated into the architecture (e.g., Lunar Communications Relay Navigations Systems)" (p. 2; the name as printed).
  • Service volume. "As the Foundational Exploration segment progresses, lunar relay service support grows to include a greater portion of the lunar South Pole region and increasing orbital altitudes (see the Architecture Definition Document for more detail)" (p. 4). That detail is the LCRNS table above.
  • Standards. "NASA's Space Communications and Navigation program β€” in coordination with relevant stakeholders β€” represents the agency when negotiating many of these standards" (p. 2).
  • Navigation accuracy. "NASA has procured systems to realize 10-meter or better accuracy" (p. 4). The paper doesn't say which systems, or whether they are part of this element.

In the 2024 executive overview

The 2024 executive overview, older than Rev C, draws the networks as two tiles in its elements spread (PDF p. 24): "LCRNS, Lunar Communications Relay and Navigation Systems", tagged "The Moon's Mobile Network", and "NASA Communications Networks", with "Near Earth Network" and "Deep Space Network", tagged "Call Home from Space". Rev C has one element holding all three, and calls the first network the "Near Space Network" (above; p. 64). The wiki doesn't read a change of element count from the tiles.

In the February 2024 workshop briefing

SCaN spoke for the Space Operations Mission Directorate at the February 2024 workshops, older than Rev B and Rev C (Mission Directorate Panel, slides 17–18):

  • Human Lunar Return contributions. "SCaN leading lunar loading analyses for the Human Lunar Return segment utilizing baselined ground rules and assumptions. Results will either validate architecture or highlight where changes are needed." Three assets: "Deep Space Network Lunar Exploration Upgrades (DLEU)", "Lunar Communications and Navigation Relay Services (LCRNS)", "Lunar Exploration Ground Segment (LEGS) (18-Meter Class Antenna Subnet)". "NASA is seeking international partnerships in space communications and navigation areas".
  • Concepts and studies. "Lunar Surface Wireless": "3GPP/5G cellular technology for a robust lunar surface C&N infrastructure that is scalable to meet long-term needs". "Lunar Navigation System": "Like GPS, but at and for the Moon"; "Supports the need for 10-m surface positioning and 25-m HLS landing knowledge requirements". "Optical Communications" ("O2O optical demonstration is on track for Artemis II"). "Deep Space Network Futures", shaping the network "from 2030 – 2050".

Against Rev C (the wiki's comparison). Rev C names LCRNS but not DLEU or LEGS (no other source text names them). The "10-m surface positioning" is #0101's Rev C target, 10 m (3Οƒ) (#0101), and surface 3GPP is #0103's subject (#0103); the pairings are the wiki's. The slide's "Like GPS" navigation system is the same idea as the ADD's lunar PNT that "may grow to" "GNSS–like" services (p. 41; C&PNT Systems).

Functions (ADD Appendix B.3)

B.3.14 splits the element in two, in each segment (pp. 163–164):

  • B.3.14.1.1 and B.3.14.2.1: "Near Space Network and Deep Space Network"
  • B.3.14.1.2 and B.3.14.2.2: "Lunar Communications Relay and Navigation Systems"

Titles are the ADD's. The last column is the wiki's join with the Users Guide's Phase 1 list (Phase 1 functional gaps).

ID Function NSN and DSN, HLR NSN and DSN, FE LCRNS, HLR and FE Moon Base Phase 1 functional gap?
FN-C-101 L Provide communications and data exchange between the lunar surface and Earth βœ“ βœ“ βœ“ yes, communications and PNT group
FN-C-102 L Provide communications and data exchange between Earth and cislunar space βœ“ βœ“
FN-C-104 L Provide communications and data exchange between Earth and deep space βœ“
FN-C-105 L Provide high bandwidth, high availability communications and data exchange between the lunar surface and Earth βœ“ βœ“ βœ“ yes, communications and PNT group
FN-C-106 L Provide high bandwidth, high availability communications and data exchange between cislunar space and the Earth βœ“ βœ“ βœ“
FN-C-201 L Provide position, navigation, and timing services at the south pole region on the lunar surface βœ“ yes, communications and PNT group
FN-C-204 L Provide position, navigation, and timing services in cislunar space βœ“ βœ“ βœ“
FN-A-201 L Control robotic system(s) in sunlit areas and non-PSRs on the lunar surface from Earth and/or cislunar space βœ“ yes, robotics group
FN-A-202 L Control robotic system(s) in PSRs on the lunar surface from Earth and/or cislunar space βœ“
FN-A-401 L Command and control asset(s) from Earth on the lunar surface during uncrewed periods βœ“ yes, robotics group
FN-A-402 L Command and control asset(s) from Earth in cislunar space during uncrewed periods βœ“

The LCRNS tables are the same five functions in both segments. The NSN and DSN gain five in FE: deep-space communications and four robotic-control functions. The lunar spreadsheet's "NSN/DSN" and "Lunar Communications Relay and Navigation System" columns are the same (Lunar function allocation).

C&PNT functions no ADD element covers (the wiki's reading of B.3 and B.5):

  • PNT away from the South Pole. PNT at distributed near-side sites (FN-C-202 L) and on the far side (FN-C-203 L) is unallocated in B.5, under eight and six use cases (pp. 169, 173–174, 177–180).
  • Lunar time. The coordinated lunar time scale, FN-C-205 L, is the one unallocated function in Human Lunar Return (B.5.1, p. 167): "All the use cases listed above share a single unallocated function". No ADD table for Foundational Exploration names it. The spreadsheet gives it to a generic "Communication/PNT Asset", which has no ADD table (Lunar function allocation). The element section's text on "Reference systems and time" is under Interoperability.
  • Surface-to-surface links are not on this element. FN-C-103 L and FN-C-107 L (between assets on the surface) are mapped to the habitat and the rovers instead (pp. 157, 159, 162).

Gaps that mention it

  • #0102 Deep Space Communications (Mars only): "Deep space communication is currently accomplished via ground-based methods using the Deep Space Network or, for Mars, a limited relay system of orbiters" (ESDMD #0102).
  • DN-012 L Surface radiation and space weather notes that "the LunaNet Interoperability Specifications (LNIS V.5) provides protocols for space weather monitoring/alert services" (DN-012 L).

(Tech gaps spreadsheet; data gaps spreadsheet.) The lunar C&PNT gaps, #0103 Surface-to-Surface Communications and #0101 PNT for Lunar Surface Extreme Environments, cover the same subjects as the surface sections above without naming the element; see C&PNT Systems.

Changes since Rev C

No source newer than Rev C names LCRNS; of those sources, only the NavCube3-mini article mentions the SCaN Program. Missions since Rev C that use the NSN and DSN are under Moon Base relevance.

  • Briefed at Ignition, March 2026: communications and PNT by phase. The Moon Base Program's deck plans lunar communications and PNT phase by phase without naming a network, element or provider (Ignition deck 2, slides 49–51):

    • Phase 1, "Orbital comm & PNT relay": "Deploy initial 5-satellite constellation"; "Add second provider constellation"; "Add observation capability". Under "Data and standards": "Mature interoperability specification baseline across all users and infrastructure - LunaNET" (slide 51). Phase 1's key missions add "Increase throughput to/from Earth to cislunar space >500 Mbps" and "Test initial LunaNET interoperability standards" (slide 14).
    • Phase 2, "Surface communications": "Permanent surface "cell towers""; "Simultaneous support for multiple users via integrated surface network terminals". "Navigation infrastructure": "Clock technology demonstration" (slide 51). The render labels a "Phase 2 Deployable Surface Comm Tower", "Phase 2 Lunar PNT" and a "Phase 2 Clock Demo" (slide 50).
    • Phase 3: "Coordinated communication across all assets in support of Moon Base"; "Scaled network deployment across regions"; "Clock ensembles – persistent time broadcast" (slide 51), and "Phase 3 High-Throughput Surface Comms" on the render (slide 50).

  • Where the deck's items sit against Rev C (the wiki's pairing, by subject). The constellations are orbital relays like those the LCRNS section describes; the deck doesn't say who operates them or whether they are LCRNS services. Its "LunaNET" baseline is the subject of the ADD's LunaNet and LunaNet Interoperability Specification (above). Its clock demonstration and "persistent time broadcast" are on the subject of the lunar time scale, FN-C-205 L, which Rev C leaves unallocated (above). Its surface "cell towers" are on the subject of #0103, surface-to-surface links, which Rev C maps to the habitat and rovers, not to this element.

  • Programs and procurement. Slide 42 attaches "COMM NETWORKS" to the deck's "INFRASTRUCTURE" area (Ignition deck 2, slides 41–42); the deck doesn't say whether these are NASA's networks. Its 2026 timeline plans a "Moon Base Lunar Communications Procurement", RFP on 1 June (Ignition deck 2, slide 63), and its Gateway slides list "existing communications HW on the Moon Base" among the repurposing options (Ignition deck 2, slide 3). The communications table by phase is also on Phases.
  • On the Moon Base Systems page (2026). The same plan in prose, by phase: "an initial five-satellite orbital relay constellation" and "a second provider constellation", a "Mature LunaNet interoperability baseline"; "lunar surface communications infrastructure" and "demonstrations of lunar timing technologies"; then "a coordinated lunar network" and "Persistent timing and navigation services enabled through advanced clock and time-broadcast systems" (Moon Base Systems, "Communications, Positioning, Navigation, Timing"). It names no network.
  • SCaN in the May 2026 realignment. SCaN becomes a division of the new Research and Technology Mission Directorate, under Kevin Coggins. The same note's Directive 6 gives the Moon Base Program "unified program authority for planning, integration, contracting, and execution across all lunar missions, including SCaN and other science and technology elements" (Administrator's workforce note, 22 May 2026; realignment release). The note doesn't say how the two fit.
  • CAPSTONE's extended mission (ended June 2026). The 2022 CAPSTONE spacecraft, not CAPSTONE 02, tested two things for "NASA's SCaN … Division": autonomous navigation software (autoNGC), whose camera-based optical navigation "at times outperformed ground-based methods for real-time onboard navigation" when the Deep Space Network, busy with Artemis II, gave it "just a few passes per week"; and delay/disruption tolerant networking, "the first to fly the latest DTN protocols beyond Earth orbit". "NASA's SCaN … Division will now use the data to demonstrate innovative networking and navigation techniques on future experiments". A Near Space Network engineer applies DTN to an astronaut "walking behind a lunar hill or descending into a crater" (CAPSTONE article, Jul 2026).
  • Lunar 5G and Wi-Fi (September 2026). A contract of about $38 million, for Glenn, to Modulate Space for "a 5G communications system for use on the lunar surface with built-in Wi-Fi 6", from a "5G Network-in-a-Box" lab demonstration to a "Lunar 5G and Wi-Fi Integrated Surface Network and Flight Demonstration on the Lunar Surface" by 31 December 2028, "to support future Moon Base surface operations" (5G contract). It names no network; SCaN's February 2024 "Lunar Surface Wireless" concept (above) and #0103's 3GPP and Wi-Fi networks are the same subject (the pairing is the wiki's).
  • A student challenge on lunar communications. The HLS Program Office's 2027 Human Lander Challenge asks for surface and orbital communications architectures, wireless networks and "Network management and scheduling" for landers and surface operations (lander communications challenge).

Moon Base relevance

The Moon Base sources name the Near Space Network and the Deep Space Network, though not LCRNS or this element. SCaN appears only around the NavCube3-mini article: its writer works for the SCaN Program office, and it lists the "Space Communications & Navigation Program" among its related terms (NavCube3-mini article).

  • Altus-1 relay (Phase One, on IM-3). "Altus-1 is the first satellite in a planned lunar relay network being developed under Intuitive Machines' Near Space Network Services contract with NASA. The network will provide communications and navigation services for missions at the Moon, including in the challenging lunar South Pole region." It carries NavCube3-mini, which "will test whether signals from GPS and Galileo satellites orbiting Earth can be used to determine a spacecraft's position near the Moon" (Moon Base Phases, "Intuitive Machines' IM-3"). The ADD's NSN is contracting "through the Commercial Services contract" for cislunar communication and PNT services (p. 64). That the web page's "Near Space Network Services contract" is that contract is the wiki's reading (open question 11).
  • NavCube3-mini delivered (13 July 2026). NASA's article on the delivery adds that the relays "are designed to enable communications and navigation for astronauts and rovers operating at the agency's future Moon Base", in a region "where direct communications with Earth can be difficult". NavCube3-mini is "a key technology demonstration aboard Altus-1, validating the use of GNSS-based navigation in the lunar region" with Earth's GPS and Galileo signals, part of "NASA's broader strategy to develop communications and navigation services that work across both commercial providers and NASA's networks" (NavCube3-mini article). This uses Earth's GNSS at lunar distance. It is not the lunar "GNSS–like" service the ADD says PNT "may grow to" (p. 41), though both are about satellite navigation at the Moon (the wiki's pairing).
  • DSN checkout. Blue Origin's Blue Moon MK1 "completed communications checkouts with NASA's Tracking and Data Relay Satellite System and the Deep Space Network" (Moon Base update, Aug 2026, "Blue Origin").
  • Phase 1 C&PNT needs. The Users Guide's targets are "a second orbital relay constellation with surface imaging capabilities and lunar surface ground stations to enable > 500Mbps capability" and "orbital navigation and timing assets" (Users Guide, p. 8). It names no network or element. See C&PNT Systems, "Moon Base Phase 1".
  • Shared function IDs (the wiki's join). Five of the element's ADD functions are on the guide's Phase 1 list. Three are in its communications and PNT group: FN-C-101 L, FN-C-105 L, FN-C-201 L. FN-C-201 L is South Pole PNT, mapped to LCRNS and to no other element. Two are in its robotics group: FN-A-201 L and FN-A-401 L, robot control and command from Earth, mapped to the NSN and DSN in FE (above). None is in B.5. The guide doesn't say which half of its definition applies to them (open question 65).

Blue Ghost Mission 2's relay demonstration uses the Lunar Pathfinder satellite (Moon Base Phases, "Firefly's Blue Ghost Mission 2"). The ADD's element section doesn't mention Lunar Pathfinder, so it isn't tied to this element here.

Elements Β· C&PNT Systems Β· #0103 Β· #0101 Β· #0102 Β· Lunar Terrain Vehicle (can act as a surface relay) Β· Gateway Β· Moon Base missions and assets

Sources

ADD Rev C, pp. 5, 41, 64–67, 298 (figure on p. 67 read from the PDF), 157, 159, 162–164, 167–169, 173–174, 177–180 Β· Lunar objective decomposition, allocation sheets Β· C&PNT white paper, pp. 2–4 (p. 3 figure read from the PDF) Β· Moon Base Phases Β· Moon Base update, Aug 2026 Β· NavCube3-mini article, Aug 2026 Β· Users Guide, p. 8 Β· Tech gaps spreadsheet, ESDMD #0102 Β· Data gaps spreadsheet, DN-012 L Β· 2024 executive overview, PDF p. 24 Β· Ignition deck 2, slides 3, 14, 41–42, 50–51, 63 Β· CAPSTONE article, Jul 2026 Β· 5G contract, Sep 2026 Β· Lander communications challenge, Sep 2026