NASA Directed to Build Nuclear Reactor for Moon Base by 2030 and Develop Nuclear Propulsion for Mars

On August 4, 2025, the Trump administration issued a directive ordering NASA to have a fission surface power reactor ready for launch to the Moon by the first quarter of fiscal year 2030 — roughly late 2029 [1]. Acting NASA Administrator Sean Duffy framed it in blunt terms: "We're in a race with China to the moon... This fission technology is critically important" [2].

The directive followed a December 2025 executive order on "Ensuring American Space Superiority" that made lunar nuclear power a national priority [3]. It is the most concrete deadline the U.S. government has ever set for deploying a nuclear reactor beyond Earth. It is also the latest in a line of space nuclear ambitions stretching back to the Eisenhower administration — a line marked by billions spent, zero operational systems delivered since 1965, and a pattern of programs killed by shifting political winds before hardware ever reached a launch pad.

Six Decades of False Starts

The United States has been here before — repeatedly.

Source: NASA / DOE / IDA estimates

Data as of Jan 1, 2026CSV

The SNAP program (Systems for Nuclear Auxiliary Power), running from the mid-1950s through 1973, produced the only U.S. nuclear reactor ever operated in space: SNAP-10A, a 500-watt unit launched in April 1965. It ran for 43 days before a voltage regulator — not the reactor — failed, and it remains in orbit today [4]. The broader SNAP effort, including dozens of radioisotope thermoelectric generators (RTGs), cost an estimated $4.2 billion in inflation-adjusted dollars [5].

After SNAP wound down, the field went dormant until 1983, when NASA, the Department of Defense, and the Department of Energy launched SP-100, a 100-kilowatt fast reactor designed for deep-space and planetary outpost use. Over 11 years the program consumed roughly $830 million before being canceled in 1994 due to "high costs, schedule delays, and changing national space mission priorities" [4].

NASA tried again in 2003 with Project Prometheus, which envisioned a 200-kilowatt nuclear-electric propulsion system powering a Jupiter Icy Moons Orbiter. Congress initially approved $3 billion over five years. NASA spent $464 million in three years before the project was killed in 2005 [4].

The smaller-scale Kilopower project, begun in 2015, produced more tangible results: a 1-kilowatt prototype reactor called KRUSTY (Kilopower Reactor Using Stirling Technology) was successfully tested at the Nevada National Security Site in 2018. But total Kilopower funding was roughly $20 million over three years — orders of magnitude less than what a flight system requires [6].

Most recently, the DRACO program (Demonstration Rocket for Agile Cislunar Operations), a joint DARPA-NASA effort to flight-test nuclear thermal propulsion, was allocated $499 million. Lockheed Martin and BWX Technologies won the development contract in July 2023 with a planned 2027 launch [7]. Then, in May 2025, the FY2026 budget request zeroed out nuclear thermal propulsion entirely. DARPA Deputy Director Rob McHenry explained the rationale: SpaceX had driven launch costs down so steeply that "the efficiency gain from nuclear thermal propulsion relative to the massive R&D costs necessary to achieve that technology started to look like less and less of a positive ROI" [8].

The total bill across all these programs: more than $6 billion, with no flight-ready nuclear power system to show for it [5].

The Current Plan: Specifications, Contractors, and Money

The Fission Surface Power (FSP) project has been restructured since the August 2025 directive. NASA established a dedicated FSP program office under Steven Sinacore and moved it from the Space Technology Mission Directorate to the Exploration Systems Development Mission Directorate [2].

The system specifications have grown since the project's early phases. Initial 2022 contracts called for a 40-kilowatt reactor under six metric tons with a 10-year lifespan. Current plans target 100 kilowatts of electrical power using a closed Brayton cycle power conversion system, with a mass budget of up to 15 metric tons enabled by heavy-class landers [2][9].

Three contractor teams received $5 million Phase 1 design contracts in 2022 [10]:

• Lockheed Martin with BWX Technologies and Creare
• Westinghouse with Aerojet Rocketdyne (the "AstroVinci" concept, scalable from 10 to 100 kWe)
• IX, a joint venture of Intuitive Machines and X-Energy, with Maxar and Boeing

The fuel baseline is HALEU — high-assay low-enriched uranium at 19.75% U-235 enrichment — staying just under the threshold for highly enriched uranium to simplify regulatory handling [2].

On funding: Trump's FY2026 budget request included $350 million for a new Mars Technology line encompassing FSP, escalating to $500 million starting in FY2027 [2]. Congress appropriated $250 million for the reactor in its FY2026 spending legislation [11]. Both figures fall far short of the $3 billion over five years that the Department of Energy's Idaho National Laboratory has estimated the program actually requires [11].

That gap — roughly $2.5 billion between what's funded and what's estimated to be needed — is the single largest risk factor the program faces, separate from any engineering challenge.

Why Not Solar? The Physics of Lunar Night

The case for nuclear power on the Moon comes down to one number: 14. That's how many Earth days the lunar night lasts.

Source: NASA Glenn Research Center

Data as of Jan 1, 2026CSV

During the lunar day, deploying enough solar panels to generate 40 kilowatts is straightforward. But sustaining that power through a 354-hour night requires batteries of a scale and mass that current technology cannot deliver to the lunar surface efficiently. Solar arrays capable of generating hundreds of kilowatts would need to cover areas the size of football fields [12]. At the Moon's south pole — where NASA plans to build and where permanently shadowed craters may hold water ice — some locations receive sunlight only intermittently.

A fission reactor, by contrast, operates continuously regardless of lighting conditions. NASA's current requirement of 100 kW continuous would power the equivalent of roughly 30 U.S. homes and support in-situ resource use, life support, science instruments, and communications infrastructure simultaneously [9].

The China Factor

The urgency behind the 2030 deadline is not purely technical. It is geopolitical.

China and Russia signed an agreement in 2024 to build a nuclear reactor for the International Lunar Research Station (ILRS) at the Moon's south pole [13]. China's Chang'e-8 mission, set for 2028, will test energy generation technologies needed for the base. The reactor itself could be installed between 2033 and 2035, with five heavy-lift rocket launches carrying components to the surface during that window [14].

China's timeline is more conservative than NASA's — but China has a track record of meeting its space deadlines. Chang'e-5 returned lunar samples on schedule in 2020. The Tiangong space station was completed on time in 2022.

The strategic concern goes beyond prestige. The August 2025 directive emphasized that first-mover advantage in establishing lunar infrastructure could enable declaring exclusionary operational zones under non-Artemis Accords frameworks — effectively giving the first party to establish power infrastructure a claim on prime south pole real estate [2]. If the U.S. misses 2030 and China delivers by 2035, the dynamic at the south pole could be set for decades.

Regulatory Gauntlet

Even if the reactor is built on time, it cannot fly without clearing a multi-agency regulatory process that has historically taken years.

Under NSPM-20 (National Security Presidential Memorandum-20, signed in 2019), all spacecraft carrying nuclear systems must pass review by the standing Interagency Nuclear Safety Review Board (INSRB), which replaced the previous mission-specific review panels [15]. The process involves NASA, the Department of Energy, the Department of Defense, the Nuclear Regulatory Commission, and the Environmental Protection Agency.

The NRC's role focuses on terrestrial handling, transportation, and storage of the nuclear materials used in space systems, as well as advising on safety analysis [16]. Any reactor using HALEU fuel must comply with NRC regulations for special nuclear material, and the launch vehicle integration must satisfy NEPA environmental review requirements [16].

For context, the safety review for the Cassini mission — which carried 72 pounds of plutonium-238 in three RTGs, a far simpler system than a fission reactor — took several years and required explicit presidential-level launch authorization through the Office of Science and Technology Policy [17]. The review concluded that the probability of a plutonium container breach was exceptionally low and that the expected health impact of even a worst-case accident would be less than one additional cancer death over 50 years [17]. Anti-nuclear activists sued unsuccessfully to block the 1997 launch [17].

A fission reactor carrying approximately 500 kg of low-enriched uranium presents a different risk profile than Cassini's plutonium RTGs [16]. The fuel is less radioactive per kilogram than plutonium-238 but far greater in mass. NSPM-20 was designed to streamline approvals, but no fission reactor has yet gone through the full process — meaning the actual timeline remains untested.

Who Pays if Something Goes Wrong?

The liability question is the least-discussed and most consequential regulatory gap.

The 1972 Space Liability Convention holds the launching state strictly liable for damage caused by its space objects on Earth's surface [18]. When the Soviet Kosmos 954 satellite — carrying 50 kg of highly enriched uranium — broke apart over Canada's Northwest Territories in 1978, the Canadian government billed the USSR Can$6 million; Moscow eventually paid Can$3 million [18].

The Price-Anderson Nuclear Industries Indemnity Act governs liability for domestic nuclear incidents at DOE facilities and licensed reactors, providing a no-fault insurance framework [19]. Whether Price-Anderson extends to cover a launch failure involving a space reactor's fuel is legally ambiguous. The act was written for terrestrial power plants, not launch vehicles.

For the Cassini launch, NASA conducted a full probabilistic risk assessment and the federal government assumed liability under its standard launch indemnification authorities. A similar framework would presumably apply to a fission reactor launch, but the political dynamics of launching hundreds of kilograms of enriched uranium on a vehicle — potentially SpaceX's Starship, which experienced multiple failures during its test program — would be substantially more charged than Cassini's 1997 context [2].

The Case for Skepticism

Critics of the 2030 deadline point to several concrete problems.

The lander doesn't exist yet. NASA relies on commercial providers for lunar landing capability. SpaceX's Starship is the intended heavy-class lander, but as of mid-2026, Starship has not demonstrated a lunar landing. Internal documents have suggested the vehicle might not be operational as a Moon lander until mid-2028, leaving minimal margin for a reactor delivery by late 2029 [11].

The budget is a fraction of what's needed. The $250 million appropriated for FY2026 is roughly one-fifth of the $3 billion five-year estimate from Idaho National Laboratory [11]. Congressional appropriations are annual and subject to political shifts — exactly the pattern that killed SP-100, Prometheus, and DRACO.

No flight-ready nuclear system has been demonstrated. The Kilopower/KRUSTY test was a 1-kilowatt prototype in a controlled terrestrial environment. Scaling to 100 kW, qualifying for spaceflight, integrating with a lander, and conducting a full INSRB safety review in under four years would be, as one NASA Glenn Research Center official involved with Artemis put it, a sequence requiring "a couple of miracles" [11].

Historical precedent is not encouraging. The Constellation program, announced in 2004 to return humans to the Moon by 2020, was found by the Augustine Commission in 2009 to be "massively underfunded" with an unrealistic schedule. It was canceled in 2010 after roughly $9 billion in spending [20]. The pattern — a politically set deadline, initial funding that falls short of independent estimates, followed by cancellation when costs escalate — is well-established in NASA's recent history.

The Department of Energy has described the 2030 target as "aggressive but achievable" [11]. Whether "aggressive" and "achievable" can coexist when the funding gap is measured in billions and the last U.S. space reactor flew during the Johnson administration is the central question.

The Case for Optimism

Proponents counter that the landscape has fundamentally changed since SP-100 and Prometheus.

The Kilopower/KRUSTY tests in 2018 demonstrated a working fission reactor prototype using flight-relevant technology for the first time in decades [6]. The three contractor teams have had since 2022 to mature their designs, and the technology readiness level is higher than any previous program at an equivalent stage.

The shift to HALEU fuel — rather than highly enriched uranium — simplifies both the regulatory pathway and the political optics [2]. And unlike Prometheus, which was tied to a speculative deep-space mission, FSP is directly connected to the Artemis lunar program, which has broad bipartisan support and its own institutional momentum.

Lockheed Martin has publicly stated that fission surface power represents "endless power in the lunar night" and that their design work is on track [21]. The establishment of a dedicated program office with streamlined management — 15 full-time engineer equivalents operating as a "minimum viable structure" — suggests NASA has learned from the bureaucratic bloat that slowed earlier efforts [2].

Nuclear Propulsion for Mars: A Parallel Track

While DRACO was cancelled, the executive order's broader space nuclear strategy did not abandon propulsion. The Office of Science and Technology Policy directed NASA to focus on "common NEP/NTP components for initial use on the potential NEP demonstrator" — essentially keeping nuclear propulsion alive through the electric propulsion pathway rather than thermal [3].

The physics case for nuclear propulsion to Mars remains strong. Nuclear thermal propulsion offers roughly twice the propellant efficiency of chemical rockets, with the potential to cut Mars transit from nine months to as little as three to four months [22]. That reduction translates directly to lower crew radiation exposure — up to 40% less deep-space cosmic ray dose compared to chemical propulsion profiles — and more abort options during transit [22].

Solar electric propulsion, meanwhile, is considered impractical for crewed Mars missions at current power levels, though it works well for cargo pre-positioning [22]. Chemical propulsion can get crews to Mars, but the longer transit imposes higher radiation risk, greater life-support mass, and narrower launch windows.

The Air Force Research Laboratory's JETSON program (Joint Emergent Technology Supplying On-orbit Nuclear Power) is separately pursuing nuclear electric spacecraft power for national security missions, with Lockheed Martin receiving a $33.7 million contract [23]. If JETSON produces flight-ready nuclear electric technology, it could provide components applicable to both in-space propulsion and surface power — a convergence that neither the civilian nor military programs could achieve alone.

What Happens Next

The next 18 months will determine whether the 2030 target is real or aspirational. NASA must downselect from three contractor teams to one or two for detailed design and fabrication. The INSRB must begin its safety review process. Congress must appropriate funding at levels far above what it provided in FY2026. And Starship must demonstrate the landing capability needed to deliver a 15-metric-ton reactor to the lunar surface.

If all of those things happen on schedule, the United States will deploy its first space reactor in 65 years. If any one of them slips significantly, the program joins SP-100, Prometheus, and DRACO on a list that now represents more than six decades and billions of dollars of ambition without follow-through — and China's ILRS moves closer to being the first permanent power infrastructure at the lunar south pole.