White House Directs Accelerated Development of U.S. Space Nuclear Power Systems

NSTM-3 establishes the overarching strategy of the Initiative as providing for “parallel and mutually reinforcing” design competitions through U.S. National Aeronautics and Space Administration (NASA) and Department of War (DOW) to meet the ambitious timelines and objectives of the EO. NSTM-3 also designates accountable leadership, requires coordination of efforts, resources, and capabilities, and prioritizes commercial innovation for each portion of the Initiative. Notably, NSTM-3 also provides for the contracting methods, including firm-fixed price, but encourages NASA and DOW to allow vendors to set their own interim milestones, particularly where tied to tangible delivery of hardware or capability demonstrations. OSTP will develop a roadmap identifying the obstacles to achieving the objectives of the Initiative and recommendations for resolving within 90 days of NSTM-3’s release.

The Role of NASA
NSTM-3 sets out short and longer-term directives for NASA. In the near term, NSTM-3 directs NASA to initiate a program that will develop a mid-power lunar fission surface power (FSP) space reactor launch by 2030, with an option for a mid-power nuclear electric propulsion (NEP) variant that could be demonstrated earlier. While these near-term directives are similar to those articulated by the agency itself in late March 2026, the NEP variant under the Initiative would be designed for compatibility with launch vehicles (not interplanetary spacecraft) and targeting deployment by 2029 (rather than 2028).

NSTM-3 instructs NASA to adopt a multivendor approach to develop the mid-power FSP, with participants advancing through design, testing, and hardware demonstration. To qualify, mid-power reactors must be capable of providing at least 20 kilowatt electric (kWe) for at least three years in orbit and five years on the lunar surface. NSTM-3 encourages NASA to consider including at least one lower-power option (at least 1 kWe), where it would reduce cost and scheduling risk, and at least one scalable design (at least 100 kWe). NASA is instructed to downselect to no more than two designs within one year of program kick-off, but may select different providers for the FSP and NEP variants based on cost and suitability (up to four total vendors).

In the longer-term, NASA is instructed to pursue development of a higher-power space reactor—at least 100 kWe—that can be deployed in the 2030s. This reactor should build on preceding NASA and DOW space nuclear programs, including selecting from the existing pool of vendors.

The Role of DOW
NSTM-3 directs DOW to pursue deployment of its own mission-enabling, mid-power in-space reactor by 2031, pending the availability of funding. Recognizing that DOW does not yet have a mission requiring such capability, NSTM-3 instructs DOW to first conduct an analysis of operationally relevant use cases and payloads from which a final mission will be selected in coordination with OSTP, the Office of Management and Budget, and the National Security Council.

NSTM-3 provides that during the first year of the Initiative, any DOW funds for space nuclear are to be contributed to the NASA program. DOW will then initiate its own competition in the second year and advance competing vendors through design and testing, encouraging participation from existing NASA and U.S. Department of Energy (DOE) participants to facilitate development of common reactor and/or power conversion designs. NSTM-3 also provides that DOW will have the ability to select from qualified NASA and DOE participants if any of its own participants are unable to meet programmatic standards or technical milestones, creating an additional safeguard.

The Role of DOE
NSTM-3 instructs DOE to assess the readiness of the U.S. nuclear reactor industrial base to produce up to four space reactors within five years, including maturity of reactor designs, and the availability of long lead-time components and fuel, and any recommendations for resolving deficiencies. DOE is also instructed to conduct the research necessary to close gaps in fuel, material, and other technology necessary to meet the Administration’s space nuclear objectives.

NSTM-3 also assigns a facilitation role to DOE, directing it to coordinate with NASA and DOW to assess the authorizations and infrastructure necessary to support their missions, as well as support National Laboratory expert consultations, conduct nuclear safety and security analyses, and provide uranium fuel where commercial sources are insufficient.

Industry Takeaways
The Initiative is designed to drive competition among multiple vendors, with early program phases intended to encourage advancement of many differentiated proposals before quickly downselecting to one or two statistically viable projects. The requirements for fixed-price contracting and payments tied to hardware delivery or capability demonstrations are intended to emphasize priority on technical readiness and timely delivery to meet the accelerated timelines set out in the EO and NSTM-3.

For interested stakeholders, including reactor developers, fuel suppliers, supply chain companies, and supporting contractors, participation will be informed by the ability to meet defined technical thresholds on compressed timelines while navigating evolving regulatory, safety, and integration requirements. Early agency solicitations are expected to focus on gathering information from industry on commercial design maturity, test readiness, and integration into planned government missions.

Pillsbury’s Space and Satellite and Nuclear Energy teams are actively monitoring these developments and are available to advise on related regulatory, procurement, and strategic considerations.