Nuclear thermal rockets in 2026: overview
A nuclear thermal rocket uses a reactor to heat a propellant, which is expelled to produce thrust. By relying on direct heat transfer rather than combustion, it can offer greater propellant efficiency than chemical propulsion while retaining high thrust. The engineering challenge is to combine reactor power, fuel integrity, heat transfer and nozzle performance in a compact system that can be tested and operated safely. Solid-core designs follow the most established engineering pathway; liquid- and gas-core concepts aim for higher operating temperatures but bring tougher fuel-containment and stability problems.
Recent work is widening beyond conventional hydrogen systems. In September 2026, University of Pisa researchers modeled catalytic ammonia decomposition inside particle-bed coolant channels, a route to adapting ammonia as propellant. A University of Alabama in Huntsville, NASA Marshall Space Flight Center and Ohio State University review in August 2026 examines engineering challenges for centrifugal liquid-core engines. These directions put propellant flexibility and fuel containment alongside high-temperature materials as central design questions.
- 1Fuel drives performance: Fuel integrity at high temperatures remains a key constraint, making material development and testing central to solid-core reactor progress.
- 2New propellant pathways: Ammonia cracking in particle-bed reactors offers a route beyond conventional hydrogen propellant, while adding reaction and flow-control complexity.
- 3Patent activity rises: With patent activity up 60% in the last 12 months, BWXT Advanced Technologies stands out with 7 patent holdings.
Top organizations working on nuclear thermal rockets
Ranked by Linknovate activity score · last 24 monthsThe activity score adds up the relevance of every patent, publication, grant and news item linking an organization to nuclear thermal rockets. Showing 7 of 46 organizations.
| # | Organization | Approach | Signals (24 mo) | Momentum | Why it matters |
|---|---|---|---|---|---|
| 1 | 
NASA
Research · United Kingdom |
General | PUB 1 · NEWS 99 | -4% | Recently, NASA and industry engineers proposed a synchronal bimodal nuclear rocket combining thermal and electric propulsion for deep-space missions. |
| 2 | 
Darpa
Research · United States |
Solid-core reactors | NEWS 38 | +92% | DARPA is partnering with NASA on DRACO, a program to demonstrate a solid-core nuclear thermal rocket for spacecraft propulsion. |
| 3 | TU
The University of Alabama in Huntsville
Research · United States |
Liquid-core reactors | PUB 17 · NEWS 7 | +0% | Recently, researchers advanced engineering analysis of the centrifugal nuclear thermal rocket, which uses rotating liquid nuclear fuel to heat propellant directly. |
| 4 | NM
Nasa Marshall Space Flight Center
Research · United States |
Liquid-core reactors | PUB 16 · NEWS 9 | +8% | Marshall Space Flight Center supports research on centrifugal nuclear thermal rockets and operates NTREES, a facility for non-nuclear testing of reactor fuel elements and materials. |
| 5 | 
Ohio State University
Research · United States |
Liquid-core reactors | PUB 9 · NEWS 10 | -64% | Ohio State researchers study centrifugal nuclear thermal propulsion, including hydrogen bubble behavior in liquid uranium and experimental characterization of centrifugal fuel elements. |
| 6 | MS
Marshall Space Flight Center
Research · United States |
Liquid-core reactors | NEWS 12 | +0% | Marshall Space Flight Center supports research on centrifugal nuclear thermal rockets and operates NTREES, a facility for non-nuclear testing of reactor fuel elements and materials. |
| 7 | 
University of Pisa
Research · Italy |
Particle-bed reactors | PUB 8 · GRANTS 1 | -88% | Recently, University of Pisa researchers modeled ammonia decomposition in a particle-bed reactor, investigating a way to improve ammonia-fueled nuclear thermal propulsion. |
| 8 | ··Hidden organizationCompany | Approach | PAT 00 · PUB 00 GRANTS 0 · NEWS 00 | +00% | Available to registered users. |
| 9 | ··Hidden organizationCompany | Approach | PAT 00 · PUB 00 GRANTS 0 · NEWS 00 | +00% | Available to registered users. |
| 10 | ··Hidden organizationCompany | Approach | PAT 00 · PUB 00 GRANTS 0 · NEWS 00 | +00% | Available to registered users. |
Leading research centers
Leading research institutions 35 total
- TUThe University of Alabama in HuntsvilleUnited StatesRecently, researchers advanced engineering analysis of the centrifugal nuclear thermal rocket, which uses rotating liquid nuclear fuel to heat propellant directly.
- NMNasa Marshall Space Flight CenterUnited StatesMarshall Space Flight Center supports research on centrifugal nuclear thermal rockets and operates NTREES, a facility for non-nuclear testing of reactor fuel elements and materials.
- Ohio State UniversityUnited StatesOhio State researchers study centrifugal nuclear thermal propulsion, including hydrogen bubble behavior in liquid uranium and experimental characterization of centrifugal fuel elements.
- ··Hidden research institutionCountryAvailable to registered users, with their key researchers.
- ··Hidden research institutionCountryAvailable to registered users, with their key researchers.
Where nuclear thermal rockets innovation happens
Share of documents with at least one organization from each country.
Open the interactive map with all 46 organizationsMain technical approaches
Last 24 months| Approach | What it is | Documents | Leading organizations |
|---|---|---|---|
| Solid-core reactors | Solid fuel heats propellant through reactor channels; the design is comparatively established, but fuel and structural materials limit operating temperatures. | 84 |
Nasa Marshall Space Flight Center, The University of Alabama in Huntsville, NASA |
| Particle-bed reactors | Propellant passes through packed fuel particles for high heat transfer, with pressure drop, fuel retention and flow control as trade-offs. | 23 |
University of Pisa, NASA, Darpa |
| Liquid-core reactors | Liquid nuclear fuel transfers heat directly to propellant and may reach higher temperatures, but fuel containment and stable operation are difficult. | 49 |
Ohio State University, NASA, The University of Alabama in Huntsville |
| Gas-core reactors | Gaseous fuel could enable very high operating temperatures, but containing the fuel while transferring heat to propellant remains a major challenge. | 13 |
Darpa, The University of Alabama in Huntsville, Nasa Marshall Space Flight Center |
Emerging trends
Last 12 months vs previous 36 monthsTerms whose frequency in the last 12 months grew the most compared with the previous 36 months.
Funding and investment
The listed grant funding totals $3,635,397 across 2 grants since 2020. No funding rounds are recorded.
Patent landscape
Top patent holders · last 24 monthsRecent developments
Latest news, duplicates removed- Oct 2026As space exploration technologies accelerate, an engine that can traverse deep space equally fast is needed- and nuclear engines could be the answer. For decades, spacecraft have relied largely on chemical rockets to…Innovation News Network
- Aug 2026One day in 1982, Joseph “Rod” Canion and two colleagues from Texas Instruments sat down at the House of Pies in Houston and used a napkin to sketch out what would become Compaq’s portable PC. In 1996, Felix Zandman…IEEE Spectrum Recent Content full text
- Aug 2026Summary - NASA and industry engineers propose a synchronal bimodal nuclear rocket (S‑BNR) to dramatically cut transit times to destinations around the solar system, such as Mars, by combining nuclear thermal and…IEEE Spectrum Recent Content full text
- Aug 2026NASA has put a date on an idea that the United States has studied for more than six decades without sending beyond Earth orbit. The agency is targeting late 2028 for Space Reactor-1 Freedom, a roughly 12-tonne…Space News From SpaceDaily.Com
- Month 20XXHidden developmentAvailable to registered users with alerts enabled.
Frequently asked questions about nuclear thermal rockets
What companies are working on nuclear thermal rockets?
The corporate organizations named in the data include BWXT Advanced Technologies, BWXT Nuclear Energy Inc., Blue Origin and General Atomics Electromagnetic Systems. BWXT Advanced Technologies has 7 patent holdings, and BWXT Nuclear Energy Inc. has 4. Blue Origin also holds a listed patent. These figures identify documented activity, not a complete supplier or manufacturing roster.
Which universities and research centers lead nuclear thermal rockets research?
The University of Alabama in Huntsville, NASA Marshall Space Flight Center and Ohio State University are prominent research groups in the listed activity. Their work includes centrifugal nuclear thermal propulsion, liquid-fuel behavior and fuel-element testing. Other active organizations include NASA, DARPA, the University of Pisa and Argonne National Laboratory.
How much funding has nuclear thermal rockets received?
The listed grant funding totals $3,635,397 across 2 grants since 2020. The funding data records no investment rounds. These figures refer to the grants captured for the topic and should not be read as a complete account of government or internal program budgets.
Who holds the most nuclear thermal rockets patents?
BWXT Advanced Technologies leads the listed patent holders with 7 patents, followed by BWXT Nuclear Energy Inc. with 4. Other named holders include the University of North Texas, Blue Origin and the United States of America as represented by NASA. The counts describe the patent activity in the topic data.
Is nuclear thermal rockets patent activity growing?
Yes. Patent activity grew 60% in the last 12 months compared with the previous 12 months, and 13 patents fall within the 24-month window. BWXT Advanced Technologies and BWXT Nuclear Energy Inc. are the most prominent listed holders. Patent growth is positive even as overall topic activity has declined.
What are the latest developments in nuclear thermal rockets?
Recent developments include University of Pisa’s model of catalytic ammonia decomposition in particle-bed coolant channels, published in September 2026, and research on centrifugal liquid-core engine challenges published in August 2026 by the University of Alabama in Huntsville, NASA Marshall Space Flight Center and Ohio State University. Together, these efforts address alternative propellants and reactor architectures.
What new methods or terms are emerging in nuclear thermal rockets?
The emerging terms include fuel assembly, propellants, reactor cores and spacecraft propulsion. Recent work also examines catalytic ammonia decomposition in particle-bed reactor channels, while a September 2026 patent describes a functionally graded lattice cermet fuel structure. These developments point to growing interest in fuel design, propellant flexibility and reactor-component engineering.
What are the main approaches in nuclear thermal rockets and how do they differ?
The four listed approaches are solid-core, particle-bed, liquid-core and gas-core reactors. Solid-core systems heat propellant through fuel elements; particle beds use packed fuel particles to increase heat transfer. Liquid- and gas-core concepts seek higher operating temperatures but make fuel containment and stable operation harder. The approaches therefore trade established engineering pathways against temperature potential and complexity.
What are the applications of nuclear thermal rockets?
The listed applications are outer-planet science missions, with 126 documents; crewed Mars exploration, with 37; cislunar and lunar transport, with 29; and deep-space cargo transport, with 13. These mission types benefit from the technology’s combination of high thrust and propellant efficiency. The figures indicate documented application activity, not mission commitments.