Power Systems (P)

Summary. Generating, distributing and storing electrical energy for elements and assets (ADD Rev C, p. 44). At first every element brings its own power; later the architecture adds augmentation and possibly "a lunar power grid" with standard two-way interfaces, and in the Sustained Lunar Evolution segment aggregate power grows "from kilowatts to megawatts". Its one Rev C element, new in this revision, is the Lunar Nuclear Fission System. Five technology gaps list it, three named in the Moon Base Users Guide (near-term). The ACR25 lunar power white paper puts the start of "external power augmentation" at the Foundational Exploration segment, sets out four architecture drivers, and defines "effective energy storage duration" (below). Decomposition letter: P.

NASA's description

"This sub-architecture comprises capabilities that supply electrical energy to elements and exploration assets. These capabilities include components and hardware for power generation (e.g., solar arrays, fission surface power), power distribution (e.g., electrical cables, induction, power management, control and distribution electronics), and energy storage (e.g., batteries, regenerative fuel cells).

Interoperability is a key aspect of the Power Systems sub-architecture. This includes standardization of power interfaces (i.e., either hard or inductive connections) and the development of compatible power quality standards. The power sub-architecture includes coordination of missions where elements provide their own power as well as developing electrical energy infrastructure to support future needs and an over-all robust, resilient, and reliable architecture.

Initially, the architecture presumes that each element and exploration asset can provide the power and energy storage needed to perform their intended missions. As the architecture progresses, the sub-architecture expands to include options such as internal augmentation, external augmentation, and/or a lunar power grid (utilizing standard bi-directional power interfaces). The potential use of multiple power units enables a broader deployment strategy with an increase in operational locations and enhanced capabilities for users." (ADD Rev C, p. 44)

In the segments

From ADD Rev C:

• Foundational Exploration. Infrastructure objective LI-1 drives "power" (p. 28). The unpressurized mobility mission includes "deployment of power generation, storage, and distribution systems at multiple locations around the lunar South Pole" (p. 29). Non-polar sorties "could require more operational, logistical, and power independence" (p. 30). An area of future work: "Establishing an external power augmentation strategy to maximize exploration capabilities" (p. 32).
• Sustained Lunar Evolution. Science capability grows "as mission duration and available power grow" (p. 34). Larger-scale economic opportunity emerges as "aggregate power grows from kilowatts to megawatts" (p. 35). "A year-round population will require power augmentation (e.g., nuclear fission power) to account for variations in sunlight over the course of the lunar year" (p. 35).
• Humans to Mars. "developing power (MI-1)" (p. 38).

Elements

Element	Segments	Source
Lunar Nuclear Fission System ("Lunar Nuclear Power System" in the FE table), added in Rev C	Foundational Exploration	ADD Rev C, pp. 9, 31

The Section 2.3 element table (pp. 45–46) omits this element; see the elements index. Its one-pager calls it "external power augmentation" that "can supplement onboard solar power systems for existing elements", the option the description above anticipates (p. 58). A later NASA page announces Lunar Reactor-1 for 2030 under the same project name, "Fission Surface Power"; matching the two is the wiki's reading (element page).

Technology gaps

Five gaps list this sub-architecture (derived from the tech gaps spreadsheet, Sub-Architectures column). MB = named in the Moon Base Users Guide (near-term).

Gap	Rating	MB
#0801 Lunar Dust-Tolerant Systems and Dust Mitigation	1	MB
#0901 Scalable Lunar Surface Power Generation	13	MB
#0903 Power Management and Distribution	24	MB
#0802 Mars Dust-Tolerant Systems and Dust Mitigation	35
#0902 Scalable Mars Surface Power Generation	45

The 2025 Architecture Update

The companion 2025 Architecture Update treats power as one of three lunar "services … akin to the utilities that serve communities on Earth", with C&PNT and logistics (p. 9):

"As the architecture expands to tackle increasingly ambitious missions, the ability to generate and share power becomes essential. While the elements used in early Artemis missions are self-sufficient from a power perspective (i.e., they can generate all the power they need using solar power systems), operating in more locations and for longer at the lunar South Pole will require additional, continuously available power to operate when solar power is not sufficient and to maximize the mass efficiency of individual systems. NASA is initiating elements like the lunar nuclear fission system to fulfill this need and is developing systems that can distribute and store power as needed." (Update, p. 9)

Its lunar-economy paragraph gives "providing commercial power on the lunar surface for government or industry customers" as an example of a service commercial entities could supply (p. 9). Elsewhere in the Update:

• More power. The fission system "significantly increases the power that the architecture can provide" (p. 16).
• The 2026 cycle. "Refining NASA's lunar power strategy" is one of the three focus areas (p. 18).
• Standards. Power is one of the three Moon to Mars architecture standards adopted in 2025 (p. 15; see RT-7).

For more, the Update points to the "Integrated Lunar Power Considerations" white paper, read below. The fission system's three functions are listed on its element page.

The integrated lunar power strategy (ACR25 white paper)

The ACR25 white paper "Integrated Lunar Power Strategy Considerations" sets out what a lunar power strategy must weigh. It is not the strategy: "NASA plans to debut its full integrated lunar power strategy based on the considerations outlined in this paper in the coming years" (p. 5). Page numbers in this section are the paper's. Points specific to fission are on the Lunar Nuclear Fission System page.

Why a strategy. "Electric power is critical to lunar exploration. Almost every exploration asset requires power to function." The South Pole offers "abundant sunlight in some locations" but "also presents challenging environmental conditions for power generation and distribution" (p. 1). It "includes limited areas of near-continuous solar illumination and areas of continuous or near-continuous darkness due to the low angle of the Sun on the horizon and local topography" (p. 2). Apollo, by contrast, visited "relatively flat mare near the lunar equator" and landed "close to local sunrise, enabling entire missions to take place during the lunar day" (p. 2).

By segment (pp. 1, 3):

• Human Lunar Return: "the architecture relies on self-sufficient elements (i.e., with no need for external power sources) — such as the Human Landing System, Lunar Terrain Vehicle, Pressurized Rover". "A combination of solar power generation and battery energy storage will support operations … with no power augmentation." (ADD Rev C maps both rovers to Foundational Exploration, not Human Lunar Return; open question 33.)
• Foundational Exploration: "Increasing mission durations, crew complements, and traverse ranges — as well as accessing more difficult surface locations — … will necessitate external power augmentation capabilities." "Beginning in the Foundational Exploration segment, NASA will implement external power augmentation."
• Sustained Lunar Evolution: "more national, international, and commercial actors may generate additional needs. Commercial power services could meet these and other future needs, with power networks expanding alongside the exploration and industrial footprint."

Survive or thrive. "More available power enables the agency to not just survive, but thrive, seizing opportunities to explore more environmentally challenging areas of interest. External power augmentation enables longer-duration crew stays, expanded crew numbers, more utilization opportunities, more robust contingency options, and increased use of in-situ resources" (p. 3). Figure Two draws the contrast: on their own, assets carry their own batteries and power systems; on a grid, they carry more payload and mobile assets gain range (p. 2). Figure Three, a "Foundational Exploration Segment Power Profile" marked "Values Notional", shows day and night power needed rising with the number of surface users until it exceeds the power available "without external power augmentation" (p. 3). Its axes and labels are on the source page.

Four architecture drivers

The paper's headings (pp. 2–3, in PDF reading order). It lists the drivers slightly differently in two other places (source page).

Driver	What the paper says
Multi-Region Support	"No single site on the Moon will enable NASA to accomplish all its lunar exploration objectives; the lunar power grid must be extensible to multiple sites in the lunar South Pole region and beyond." Power must also reach "sites with longer periods of darkness, including non-polar regions". The key trade is "larger, centralized systems versus smaller, distributed systems": large systems need bigger landers and longer transmission; small ones are "easier to land, move, and deploy in the near term, but might not necessarily meet long-term needs"; a mix "would require multiple parallel development efforts" (p. 2).
Minimizing Mass	External augmentation "could reduce the mass of onboard power systems". "Reducing energy storage requirements could replace significant power system mass with hardware focused on core architecture functions". The savings "could also allow capacity for additional scientific payloads or technology demonstrations", and a grid could give "backup power to ordinarily self-sufficient exploration assets" (p. 2).
Balancing Complexity	Augmentation "creates manifest and power interface dependencies … NASA must emplace external power systems before landing assets that rely on external power". A grid adds "deployments, connections between assets, concepts of operations, and flow-down impacts on mission planning". New technologies offer "lower mass, longer operational life, and higher reliability. But their immaturity introduces both development and operational risks" (p. 3).
Lunar Segment Extensibility	Augmentation is needed from Foundational Exploration on; the strategy "must consider implementation timeline to maximize power augmentation's impact". "Thoughtful implementation of power augmentation systems in the near term could increase science and exploration returns in the long term" (p. 3).

Technologies: generation, storage, transfer

Generation. "NASA considers two main power generation technologies for its crewed surface exploration architectures: nuclear fission power and solar power" (p. 3). Both need "offloading, emplacement, setup, and connection to a lunar power grid, and a potential, longer-term need for maintenance", by crew, autonomous systems or both (p. 3). The paper's table (p. 4):

	Nuclear	Solar
Availability	Continuous	Only in sunlight
Maturity	Prior experience limited to low-power, radioisotope power systems	Extensive spaceflight heritage
Unique Factors	Human-rated radiation shielding; long-distance power cabling	Tall masts increase array height above the surface; needs energy storage for night power

• Solar is "reliable and well-understood (though NASA has yet to demonstrate the large, vertical systems needed for lunar polar applications)". "Raising the height of a solar array can overcome local terrain shadowing, but increases the system's mass and complexity." "An architecture that relies solely on solar power would need complementary energy storage systems to manage prolonged periods of extreme dark and cold" (p. 4).
• Where solar can't work. "Some regions — such as high-priority science targets in craters — experience extended periods of darkness or intermittent shadows from local terrain. NASA cannot rely on the continuous availability of sunlight for power in these locations and would need non-solar power solutions to survive the lunar winter" (p. 4).
• Fission: see the element page.

Storage. Batteries or regenerative fuel cells on the grid "could reduce the required mass of individual exploration assets", and "For certain sites or operational scenarios, grid-based energy storage might be necessary for exploration assets to survive the lunar winter" (p. 4). The paper's key term:

Effective Energy Storage Duration: "The number of hours of energy storage capacity needed to account for the annual worst-case recharge and discharge of solar-generated power (i.e., winter survival mode)." (p. 4)

• "Lunar winter presents the driving conditions" for it (p. 4). Figure Four shows "how the effective energy storage need of an asset can be greater than the maximum period of continuous darkness" (p. 4).
• It "varies greatly across lunar South Pole sites. As such, an integrated lunar power strategy must consider site selection as a key design factor in assessing power system options". "Nuclear power's continuous output reduces the net energy storage requirement" (p. 5).
• Mass. "Analyses have shown that conventional lithium-ion batteries would account for more than one-fourth of the mass of a theoretical 15-metric ton habitation asset delivered to the lunar surface" (p. 5).
• Beyond batteries. "Regenerative fuel cells use chemical reactions to store energy. While these newer technologies have less flight heritage than traditional batteries, innovative approaches for energy storage could transform the power trade space" (p. 5).

Transfer. "Separation distances could range from several meters between co-located assets at a single site to several kilometers." NASA's analyses "consider two approaches to transfer power: cabling and power beaming" (p. 5).

• Cabling. Cables and electronics "must be robust to the lunar environment, accounting for extreme temperatures, dust, vacuum, and lower gravity. Cable connectors must also be interoperable with the wide variety of exploration assets", and designed "for easy handling during deployment by astronauts and robotic systems, with provisions for maintenance" (p. 5).
• Power beaming "is a relatively new technology that needs further research and development for lunar applications". Lasers or microwaves could beam power "from a crater rim into the crater valley or from an orbiting asset to a surface user". "For close-proximity charging, wireless transfer with inductive coupling could eliminate the need for hard-wired power connectors" (p. 5).

Mars-forward. "Proving new capabilities and concepts of operations closer to Earth is safer, faster, and less expensive than performing them for the first time on Mars. NASA needs to develop proficiency in deploying, connecting, and maintaining power systems with humans and robotic systems in challenging environments" (p. 5). Lunar power work can also feed "in-space power generation and nuclear- and solar-electric propulsion systems" (p. 5).

What comes next. NASA "will initiate an integrated surface power element into the architecture to realize functional capabilities for external power augmentation" (p. 5), and "is initiating new power elements into the architecture" (p. 6). The paper doesn't say whether this is the Lunar Nuclear Fission System, which ADD Rev C lists as added in 2025 (open question 32).

Links the paper doesn't make (the wiki's pairing, by subject):

• The completed definition task LD-101, "Lunar External Power Augmentation", whose outcome is to "pursue power augmentation trades that balance element design, aggregate power demand, total surface landed mass, mission-to-mission flexibility, and architecture robustness" (ADD Rev C, p. 75; Key definition tasks).
• Gaps #0901 (generation and storage; its children include nuclear, solar, fuel cells and storage), #0903 (power management and distribution; child 0903-04 is "Power transfer in dusty surface environments") and #0301 (surviving extended lunar shadow).

In the February 2025 workshop briefing

Ten months before Rev C, ESDMD's worked example of a Foundational Exploration "integrated gap" was "Power Sharing at Lunar South Pole", with seven functions, a distributable-power target and relocatable systems sized by mass (FE gaps deck, slide 3); its figures and the comparison with the fission element are on Foundational Exploration.

Moon Base Phase 1

The Users Guide's "Power systems" group: "Systems to generate, store, condition, and distribute electricity for the Moon Base, supporting infrastructure, and utilization systems" (Users Guide, p. 10). Power is "a critical shared resource". Five FN-P functional gaps: generate, store and distribute power in the South Pole region, and power deployed utilization payloads. Capability targets: "5 kW power generation and storage, as well as survival through 120+ hours of darkness", and "survive the night capability using radioisotope thermal generators". #0903 is cited under more Moon Base challenges than any other tech gap. Nuclear technologies are one of the guide's Mars-forward areas (Mars-forward). Full list: Phase 1 functional gaps.

Related pages

Sub-architectures · ISRU Systems · Sustained Lunar Evolution · Foundational Exploration · Elements · Gaps index · Lunar power white paper · Key definition tasks

Sources

ADD Rev C, pp. 9, 28–32, 34–35, 38, 40, 44, 75 · 2025 Architecture Update, pp. 9, 15–16, 18 · Lunar power white paper, pp. 1–6 (all checked against the PDF) · Tech gaps spreadsheet · Users Guide, pp. 10, 12–13 · FE gaps deck, February 2025, slide 3