Foundational Exploration (FE)

Summary. The second segment: "Expansion of lunar capabilities supporting complex orbital, surface, and Mars precursor missions" (ADD Rev C, p. 22). It brings longer surface stays, rovers, a surface habitat, fission power and cargo landers to the South Pole region, and uses lunar missions as Mars analogs. It has the most detail of any segment: seven reference missions, 15 elements plus the Gateway Logistics Element, and ten areas of future work. 32 of the 57 technology gaps list it, including 17 of the 19 named in the Moon Base Users Guide (near-term).

All page numbers below are ADD Rev C unless marked otherwise. For what segments are, see Segments.

Description

• "The Foundational Exploration segment includes increasingly complex missions and excursions to a variety sites of interest on the lunar surface for science and utilization. This segment also helps evaluate the systems, operations, human adaptations, and technologies required for Mars. … These precursor missions will inform element design, testing, and operation for Mars missions. Foundational Exploration also begins the development of a sustainable human presence with the deployment of demonstrations and capabilities that will enable long-term infrastructure and sustained surface operations" (p. 22).
• It "continues to use many of the elements from Human Lunar Return while deploying new capabilities. Segment surface missions will feature increased durations, expanded mobility, and regional exploration of the lunar South Pole. Orbital operations will also increase in duration and — when coupled with the surface mission phases — serve as Mars mission analogs, validating systems and concepts of operations" (p. 27).
• It "will initiate activities and capabilities influenced by future needs in the Sustained Lunar Evolution and Humans to Mars segments. These activities include reconnaissance, Mars risk reduction, and initial infrastructure supporting long-term lunar access and utilization" (p. 27).

Objectives

Codes are quoted as printed; prefixes are the goals on Objectives: the ten goals.

• Science (pp. 27–28), with priorities from "NASA's Science Mission Directorate, Human Research Program, and Space Technology Mission Directorate": the Moon's history and geology "with expanded surface exploration range and sampling capabilities" (LPS-1, LPS-2); volatiles (LPS-3); "space weather forecasting" (HS-1); "how living organisms respond to partial gravity and deep space environments" (HBS-1, HBS-3); and "relativity and quantum physics experiments in the lunar environment" (PPS-1, PPS-2).
• Infrastructure (p. 28). "The lunar infrastructure objectives help define the Foundational Exploration segment." The ADD ties them to sub-architectures: "Expansion of the power (LI-1), C&PNT and data systems and management (LI-2, LI-3), transportation (LI-5, LI-6), mobility (LI-6), ISRU (LI-7), and utilization (LI-9) sub-architectures alongside surface infrastructure development to support industry (LI-4, LI-8)". LI-6 appears twice as printed.
• Transportation and habitation (p. 28). TH-1, TH-2 and TH-11 "address a need for transportation systems to transfer crew and cargo to and from Earth, through cislunar space, and between lunar orbit and the surface". "TH-3 and TH-4 define Foundational Exploration as a segment building toward and enabling initial crewed missions to Mars through analog missions and technology development that support architecture definition tasks and risk reduction."
• Operations (p. 28). "extended-duration missions in deep space and partial-gravity environments to test systems and crew concepts of operations in preparation for the initial human Mars exploration campaign (OP-1, OP-2, OP-4, OP-5, OP-6, OP-7)"; "developing methods of working with robotic systems (OP-9, OP-10) and characterizing in-situ resources (OP-3)".

The lunar objective decomposition spreadsheet has a set of sheets labeled "FE+" that gives 52 objectives, 163 use cases and 208 functions, with an allocation to assets. "FE+" isn't defined, and the wiki doesn't equate it with this segment: see Lunar objectives and Lunar function allocation.

Reference missions

"Notional", and like Human Lunar Return's, "they are not specific missions NASA will conduct" (p. 28).

Reference mission	What it covers
Unpressurized Mobility (p. 29)	Builds on HLR surface exploration, "which includes crew habitation in an EVA-capable crew lander". An "unpressurized mobility platform to extend EVA range and scientific exploration" enables excursions around landing sites, robotic assistance, "crewed/robotic collection of samples from permanently shadowed regions", and "deployment of power generation, storage, and distribution systems at multiple locations around the lunar South Pole".
Pressurized Mobility (p. 29)	Longer exploration, science and industrial utilization, and "Mars risk reduction activities". Use cases include crew IVA research, longer surface stays, logistics and waste management, excursions, EVA egress and ingress, and "crew relocation and exploration in a shirt-sleeve environment". Brings more needs for "logistics transport and stowage, trash disposal, maintenance", and must "mitigate increasingly complex challenges of the lunar environment, such as dust, plasma interactions, radiation, etc."
Robotic Uncrewed Operations (p. 29)	Surface assets "will likely spend most of the year uncrewed". Objectives met "with the help of autonomous, local tele-operations, or Earth-based remote operations". Robotic functions: "cargo unloading, logistics transfers, surface and/or sub-surface sample collection, and infrastructure development (e.g., landing site scouting or preparation)"; robotic survey of crewed landing sites, "uncrewed relocation of mobility elements", autonomous deployment of science packages.
Extended Surface Habitation Operations (pp. 29–30)	A dedicated surface habitat extends duration, crew size, EVA and sample collection. Habitation systems "could also demonstrate progressively regenerative and self-sustaining environmental control and life support systems, advancing Mars-forward technologies". Needs "robust crew medical systems and health kits; space-based manufacturing techniques allowing repairs and replacement; enhanced surface EVAs; and interfaces for logistics transfers". Systems sized for uncrewed periods "may need augmentation" later in the segment.
Extended Cislunar Operations at Gateway (p. 30)	"numerous, long-duration crew increments in cislunar space" to "support crew transitions between microgravity and partial gravity". Main use case: "conducting precursor Mars mission profiles with extended durations in NRHO, followed by lunar surface missions", allowing "long-term physiological, psychological, team performance, and operational assessments".
Cislunar Orbit Only (p. 30)	Crewed missions "to lunar orbit without a subsequent landing", controlling surface assets "from Earth and lunar orbit" with "near–real-time robotic teleoperations".
Non-polar Lunar Sortie (p. 30)	Landing beyond the South Pole for science and utilization. "These missions would be conducted opportunistically — not as the primary mission profile for this segment" and "could require more operational, logistical, and power independence."

Elements

From the table on pp. 31–32, checked against the PDF. Each element has a page; see the elements index. "The Foundational Exploration segment will continue to use elements introduced in Human Lunar Return while adding new capabilities as they become available. Interoperability between elements will be especially important during the segment" (p. 30).

Element (as named on pp. 31–32)	Sub-architecture	New in FE?	ADD section	Mapping
Commercial Lunar Payload Services	Transportation Systems		2.3.1	B.3.1
Exploration EVA Systems	Mobility Systems		2.3.2	B.3.2
Exploration Ground Systems	Infrastructure Support		2.3.3	B.3.3
Gateway Crew-Capable Configuration	Habitation Systems		2.3.4	B.3.4
Gateway Logistics Element	Logistics Systems		2.3.4.1.4	B.3.4.2.1
Human Landing System	Transportation Systems		2.3.5	B.3.5
Human-Class Delivery Lander	Transportation Systems	new	2.3.6	B.3.6
Initial Surface Habitat	Habitation Systems	new	2.3.7	B.3.7
Lunar Nuclear Power System (headed "Lunar Nuclear Fission System" in Section 2.3)	Power Systems	new	2.3.8	B.3.8.1
Lunar Surface Cargo Lander	Transportation Systems	new	2.3.9	B.3.9
Lunar Terrain Vehicle	Mobility Systems	new	2.3.10	B.3.10
Lunar Utility Rover	Mobility Systems	new	2.3.11	B.3.11
Orion Spacecraft	Transportation Systems		2.3.12	B.3.12
Pressurized Rover	Mobility Systems	new	2.3.13	B.3.13
Space Communications and Navigation Networks	C&PNT Systems		2.3.14	B.3.14
Space Launch System	Transportation Systems		2.3.15	B.3.15

"New in FE" means not in the Human Lunar Return table (p. 26); the wiki's comparison. The Gateway Logistics Element and Human Landing System carry different mapping numbers here than in the HLR table (B.3.4.2.1 and B.3.5, against B.3.4.1.1 and B.3.5.1); see the elements index. Appendix B has all of those sub-sections, one per segment. Each element's FE functions (B.3) are on its own page.

Areas of future work

"This segment also includes some unallocated functions (see Appendix B.5) that are not yet met by existing systems, reference missions, or planned operations" (p. 32). The ten areas, as printed:

• "Using lunar assets and operations to prepare for crewed Mars missions"
• "Identifying a balance of mission types and locations to maximize objective satisfaction and scientific exploration"
• "Establishing an external power augmentation strategy to maximize exploration capabilities"
• "Distributing exploration assets and infrastructure to promote extensibility"
• "Increasing cargo mass delivered to and returned from the lunar surface"
• "Assessing the role of ISRU in lunar exploration"
• "Incorporating waste management approaches and element repurposing, recycling, and disposal for extended durations"
• "Operating assets and maintaining asset health during uncrewed periods"
• "Maximizing opportunities for uncrewed operations"
• "Formulating a lunar orbital observation strategy to support utilization and exploration"

What Appendix B.5 lists for this segment. 75 use cases and 77 functions that no element performs (pp. 168–184). They include:

• all 15 ISRU functions
• propellant storage and surface transfer
• power, PNT and mobility at sites away from the South Pole
• month-plus habitation, countermeasures and in-mission training
• the cryogenic sample chain and large returns to Earth
• deep drill cores
• large-volume data for real-time analysis
• orbital observation (FN-U-101 L)

Several match the areas of future work above: ISRU, waste management, cargo returned from the surface, orbital observation. That reading is the wiki's. The whole list, use case by use case, and its comparison with the lunar spreadsheet's 76 "Unallocated" functions are on Lunar function allocation.

Two ACR25 white papers are framed by this segment:

• Power. "Integrated Lunar Power Strategy Considerations" says "Beginning in the Foundational Exploration segment, NASA will implement external power augmentation", because "Increasing mission durations, crew complements, and traverse ranges" will require it (lunar power white paper, p. 1). That is the subject of the third area above; the paper doesn't cite the list, so the link is the wiki's. See Power Systems.
• C&PNT. "Communications and Navigation Needs for the Foundational Exploration Segment" covers how communications and navigation must grow through "early, mid, and late" phases of the segment (C&PNT white paper, p. 4). See C&PNT Systems.

In the February 2024 workshop briefing

A year before that list, a February 2024 breakout titled "Priorities for the Foundational Exploration Segment" framed the segment in picture slides, without figures (FE breakout):

• Six priorities (slide 3): "Mission Duration"; "Surface Crew Size & Duration"; "Science and Utilization"; "Mobility"; "Logistics"; "CPNT Architecture".
• Lunar infrastructure (slide 4): "Surface Power", "Surface CPNT" (a map with "Reliable WiFi 100 m", "Intermittent WiFi 300 m", "UHF/SSCS 1.0 km" and "EVA Range 2 km") and "Orbital Elements".
• Nine "Technical Advancements" (slides 5–6): "Conditioned Sample Return", "Increase Down-Mass to Surface", "Maintaining Asset Health During Uncrewed Periods", "Dust (Regolith) Mitigation", and "Logistics Services", "Cargo Return Services", "Surface Power Services", "Data Services", "Cooperative Extensibility".
• Questions for the room (slide 7): "What gaps are of interest?", "What challenges do you see going into the Foundational Exploration segment?", "What emerging technologies should get more attention?"

Against later sources (the wiki's comparison): the 2024 priorities return in February 2025 as integrated gaps (power sharing, high-capacity mobility, logistics, large cargo delivery and return, extended habitation, cryogenic samples, below), and in Rev C's areas of future work (above); crew size and stay length were settled as legacy decisions (Key definition tasks). Slide 6's "Services" phrases are not in Rev C's text (searched), apart from the Gateway's "Logistics Services" contract. STMD's breakout at the same workshop listed its lunar infrastructure investments (technology and infrastructure breakout).

In the February 2025 workshop briefing

At both February 2025 workshops, ten months before Rev C, ESDMD's Strategy and Architecture Office listed what this segment still lacked as "integrated gaps", by sub-architecture (FE gaps deck, slides 4–5). Rev C doesn't carry the list, and no other source uses the term. The briefing is context, not the architecture of record.

• Eleven "High Priority Gaps", each with a "Summary Element Need": Power Sharing at Lunar South Pole ("2 Major (power + interface/cabling), stretch 2-3 more elements"); High-Capacity Mobility at Lunar South Pole ("2-3 Major Elements"); Logistics Delivery and Mgmt Systems; Water and Gas Transfer on Lunar Surface; Large Cargo Delivery to the Lunar Surface ("2-3 major elements"); Large Cargo Return from NRHO to Earth or from Lunar Surface to Earth ("2 major elements, return vehicle & Gateway docking mitigation"); Extended Crew Habitation at Lunar South Pole; Extended Crew Habitation in NRHO; and three utilization gaps "Pending Utilization Analysis" (resource identification, deep subsurface sampling, storage of cryogenic samples). "Priority defined by the significance of closure to objective satisfaction and overall mission capability achieved" (slide 4), not the technology gaps' four criteria (Gaps index).
• Sixteen "Secondary Gaps", "Targeted needs and gaps to enhance FE and/or enable technology and capabilities for Humans to Mars Segment" (slide 5): crew mobility, power sharing and PNT at distributed or non-South Pole sites; far-side EVA; lunar surface observation; in-space data processing; delivery of payloads and hosting of utilization payloads in deep space; robotic assistance of crew; waste streams; oxygen and water ISRU and regolith-based ISRU demonstrations; autonomous construction; long-term propellant storage; access to tank residuals; advanced ECLSS.
• Partner interest. The international deck adds an "Expressed Partner Interest" column of dots, most on high-capacity mobility (seven), then South Pole power sharing and non-South Pole PNT (four each); no key is given (international deck).
• The worked example, "Power Sharing at Lunar South Pole" (slide 3): seven functions (FN-P-101 L, -202 L, -301 L, -401 L, -402 L, FN-U-414 L, -415 L); ">10 kW estimated distributable power in South Pole region"; "Minimum closure 2 major elements: Power generation and/or storage of 10kW; Power distribution/interface/cabling system"; "Power system ranges from 3 to 10 kW or greater"; "Estimate 2-4 ton relocatable systems"; "Multiple ways to address this gap are possible".

Against Rev C (the wiki's comparison). Several integrated gaps share a subject with Rev C's ten areas of future work above: power (the power augmentation strategy), large cargo delivery and return ("Increasing cargo mass delivered to and returned from the lunar surface"), the ISRU demonstrations ("Assessing the role of ISRU"), waste streams, the distributed-site gaps ("Distributing exploration assets and infrastructure") and the secondary list's Mars purpose ("Using lunar assets and operations to prepare for crewed Mars missions"). The ten areas have no counterpart to the habitation, mobility and utilization rows, though B.5 (above) lists unallocated functions on those subjects: month-plus habitation, the cryogenic sample chain, deep drill cores, and mobility and PNT away from the South Pole. Rev C has none of the element sizing. Of the power example's seven functions, Rev C maps three (FN-P-101 L, FN-P-301 L, FN-P-401 L) to the Lunar Nuclear Fission System, added after the workshops; the slide names no element or technology.

Gaps that list this segment

Derived from the spreadsheets' segment columns.

• Technology gaps: 32 of 57 (tech gaps spreadsheet, Segments column). All 32 also list Sustained Lunar Evolution. MB marks the gaps named in the Moon Base Users Guide (near-term) (gaps index): #0101 MB, #0103 MB, #0201 MB, #0202, #0301 MB, #0302, #0303, #0305, #0307, #0501, #0504 MB, #0505 MB, #0601 MB, #0603 MB, #0604 MB, #0701 MB, #0702, #0801 MB, #0804 MB, #0805, #0806 MB, #0807 MB, #0808, #0901 MB, #0903 MB, #1002, #1003, #1005, #1101 MB, #1106, #1107, #1201. That is 17 of the 19 Moon Base gaps. The other two, #1001 and #0605, don't list FE.
• Data gaps: 2, the resource-exploration pair DN-006 L (orbital water-ice mapping) and DN-007 L (in-situ water ice) (data gaps spreadsheet, Segment column).

Changes since Rev C

Two of the seven reference missions depend on Gateway or crewed missions to NRHO (Extended Cislunar Operations at Gateway; Cislunar Orbit Only), and Gateway is an element here. The Users Guide reports that Gateway's Power and Propulsion Element now goes to SR-1 Freedom (Users Guide, p. 2). None of the wiki's sources says what that means for this segment. See Segments and Gateway. Other changes to FE elements since Rev C: LTV vendors were selected in May 2026; Lunar Reactor-1 is announced for 2030; and the SLS upper stage and mobile launcher are being standardized, where Rev C has EGS transition to Mobile Launcher 2 for SLS Block 1B on the way into this segment (SLS; EGS).

Moon Base relevance

Not established by the sources so far. No source maps this segment to a Moon Base phase, and the wiki does not assume one. Several FE topics (rovers, surface power, cargo landers, habitation) are also Moon Base Phase 1 capability areas (Phase 1 functional gaps), but no source links the two; that observation is the wiki's.

Related pages

Segments · Human Lunar Return · Sustained Lunar Evolution · Humans to Mars · Elements · Sub-architectures · Gaps index · Mars-forward

Sources

ADD Rev C, pp. 22, 27–32 · Lunar power white paper, p. 1 · C&PNT white paper, p. 4 · Tech gaps spreadsheet · Data gaps spreadsheet · Users Guide, pp. 2, 12–13 · FE gaps deck, Feb 2025, slides 3–5 · its international copy, slides 4–5 · FE breakout, Feb 2024, slides 3–7