{"id":83171,"date":"2025-07-22T12:29:12","date_gmt":"2025-07-22T12:29:12","guid":{"rendered":"https:\/\/www.europesays.com\/us\/83171\/"},"modified":"2025-07-22T12:29:12","modified_gmt":"2025-07-22T12:29:12","slug":"making-a-new-case-for-space-nuclear-power","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/83171\/","title":{"rendered":"Making a new case for space nuclear power"},"content":{"rendered":"\n\"DRACO\"\/<\/p>\n

NASA and DARPA had selected Lockheed Martin and BWXT in 2023 to develop a nuclear thermal propulsion demonstration spacecraft for NASA\/DARPA\u2019s DRACO program, but DARPA recently pulled the plug on the effort. (credit: Lockheed Martin)<\/p>\n<\/td>\n<\/tr>\n

by Jeff Foust
Monday, July 21, 2025<\/p>\n

\nLike so many space projects, DRACO started with a bang but ended with a whimper.\n<\/p>\n

\nThe bang was in January 2023, when the leaders of NASA and DARPA took the stage at the AIAA SciTech Forum outside Washington to announce they were partnering on the Demonstration Rocket for Agile Cislunar Operations (DRACO) project. DRACO would demonstrate nuclear thermal propulsion, or NTP, a technology many saw as key to enabling rapid missions to Mars or extreme mobility closer to home. \u201cOur goal is to launch and demonstrate a successful nuclear thermal engine as soon as 2027,\u201d Bill Nelson, NASA administrator at the time, said.\n<\/p>\n\n\u201cThe understanding of the risks and the challenges of launching a reactor were probably underestimated in the beginning of that program,\u201d DARPA\u2019s McHenry concluded.<\/td>\n<\/tr>\n

\nSeveral months later, the agencies selected Lockheed Martin to develop the DRACO spacecraft (see \u201cNuclear space gets hot\u201d,<\/a> The Space Review, July 31, 2023). After that, though, DRACO faded into the background, with only occasional updates from the agencies. More recently, there had been reports that work on DRACO was slowing, or had stopped entirely.\n<\/p>\n

\nIt was not until the release of NASA\u2019s fiscal year 2026 budget request at the end of May, though, that the public found out about DRACO\u2019s demise. In a document filled with proposed cancellations of dozens of NASA missions, the agency said it was requesting no money for its share of DRACO. \u201cThe request also reflects the decision by our partner to cancel the Demonstration Rocket for Agile Cislunar Operations (DRACO) project,\u201d the document stated, without further details.\n<\/p>\n

\nA DARPA official later said that several factors contributed to DRACO\u2019s demise. Rob McHenry, deputy director of DARPA, said at a recent webinar by the Mitchell Institute for Aerospace Studies that the agency started DRACO before what he called a \u201cprecipitous decrease in launch costs\u201d by SpaceX as well as a reevaluation of whether NTP was the best approach.\n<\/p>\n

\n\u201cAs the launch costs came down, the efficiency gained 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,\u201d he said. \u201cSo, the national security operational interest in the technology was decreasing proportionally to that perception.\u201d\n<\/p>\n

\nThere was also growing interest in nuclear electric propulsion, or NEP, which offers much higher efficiencies in terms of specific impulse compared to NTP, albeit with lower thrust levels. NEP also offered the advantage of providing a source of electrical power\u2014it uses a nuclear reactor to generate electricity for the electric propulsion system or for other applications\u2014whereas NTP simply used the heat of a nuclear reactor to transfer energy to a propellant like liquid hydrogen.\n<\/p>\n

\n\u201cNuclear electric is probably a more optimal long-term solution,\u201d McHenry said. \u201cThat power in the space domain may be the critical enabler as much as the propulsion efficiency.\u201d\n<\/p>\n

\nHe also suggested DARPA was running into problems testing DRACO\u2019s NTP technology on the ground, citing \u201cinfrastructure barriers\u201d for the project. \u201cWe want to do the disruptive tech. We don\u2019t want to go spend massive amounts of money in improving core infrastructure of other government facilities.\u201d\n<\/p>\n

\n\u201cThe understanding of the risks and the challenges of launching a reactor were probably underestimated in the beginning of that program,\u201d he concluded, leading DARPA to walk away from the project.\n<\/p>\n

\nThe announcement of DRACO\u2019s demise was a first blow in a double-whammy for space nuclear advocates. The same NASA budget proposal that revealed DRACO\u2019s cancellation also put no funding towards NASA\u2019s own research into both NTP and NEP.\n<\/p>\n\nThe report noted the US had spent nearly $20 billion in constant-year dollars on space nuclear programs over the years, such as NERVA in the 1960s and Prometheus in the early 2000s, with little to show for it.<\/td>\n<\/tr>\n

\n\u201cThese efforts are costly investments, would take many years to develop, and have not been identified as the propulsion mode for deep space missions,\u201d the document stated. \u201cThe nuclear propulsion projects are terminated to achieve cost savings and because there are other nearer-term propulsion alternatives for Mars transit.\u201d\n<\/p>\n

\nCongress may not go along with that move. A spending bill advanced by the Senate Appropriations Committee last week rejected the cuts, directing NASA to spend at least $110 million on nuclear propulsion. It also includes $10 million to create a \u201ccenter of excellence\u201d for nuclear propulsion research to be located in a region that does not have a NASA center but does have \u201ca large population of industry partners who are also invested in nuclear propulsion research.\u201d The House Appropriations Committee is scheduled to mark up its version of a spending bill that includes NASA later this week.\n<\/p>\n

Powering up space nuclear<\/p>\n

\nThe cancellation of DRACO is the latest in a long line of setbacks for advocates of space nuclear power and propulsion. There have been few successes since the launch six decades ago of SNAP-10A, the first and only US space nuclear reactor.\n<\/p>\n

\n\u201cEverything since 1965, when we launched our first reactor, has fizzled despite billions invested,\u201d said Bhavya Lal, former NASA associate administrator for technology, policy and strategy. \u201cWe remain in R&D purgatory, producing papers, not kilowatts.\u201d\n<\/p>\n

\nIn the case of DRACO, she said, \u201cnobody was asking for it, and when things got in a jam, it was easier to let it go.\u201d\n<\/p>\n

\nShe was speaking at a Washington Space Business Roundtable event last week to discuss a new report<\/a> she and Roger Myers, a former Aerojet Rocketdyne executive and member of the National Academy of Engineering, recently completed for the Idaho National Laboratory regarding development of space nuclear power. That report noted the US had spent nearly $20 billion in constant-year dollars on space nuclear programs over the years, such as NERVA in the 1960s and Prometheus in the early 2000s, with little to show for it.\n<\/p>\n

\n\u201cOne core insight of our study is that the US didn’t fail to deploy space nuclear systems because we lacked the physics or the funding or the people,\u201d she said. \u201cWhat we didn’t have was mission pull, institutional coherence, and a sense of scale.\u201d\n<\/p>\n

\nLal described a vicious cycle where a lack of demand, or \u201cmission pull,\u201d resulted in a lack of technology development and flight opportunities, and thus a lack of trust by mission planners in space nuclear technology. When there were nuclear programs funded, she argued agencies overreached, trying to do too much too quickly, like NASA did with Project Prometheus two decades ago. \u201cTime and again we have tried to begin with building the space equivalent of the SR-71 when we should have started with the Wright Flyer.\u201d\n<\/p>\n

\nThose factors that have hindered development of space nuclear power are changing. One change, she noted, is the emergence of a mission pull for the technology. NASA, in its Moon to Mars Architecture development, recently identified fission power as its requirement for surface power on Mars missions.\n<\/p>\n

\nAnother is geopolitics. China and Russia have proposed developing megawatt-scale nuclear power systems for the International Lunar Research Station program they plan to establish in the south polar regions of the Moon.\n<\/p>\n

\n\u201cA continuously operating Chinese reactor on the lunar south pole would create de facto territorial control and justify exclusion zones under the guise of safety, and they would be right to do so,\u201d she said, citing provisions of the Outer Space Treaty. That could require others to seek permission to land in the region to comply with that interpretation of the treaty\u2019s language on avoiding interference. \u201cIn space as on Earth, first movers make the law.\u201d\n<\/p>\n\n\u201cA 2028 ground test and a 2030 flight aligns with budget cycles, agency leadership terms, and congressional expectations,\u201d Lal said. \u201cMiss it and we risk stakeholders walking, funding drying up, and competitors defining the future without us.\u201d<\/td>\n<\/tr>\n

\nIn the paper, Myers and Lal call for the rapid development of a space nuclear power system, with or without propulsion. The goal is to have a system ready for ground tests in 2028 and an in-space demonstration in 2030. \u201cWe found that if we need to make progress in space nuclear, we need to begin with a small, manageable system on a timeline that keeps stakeholder interest,\u201d Lal said.\n<\/p>\n

\nThe paper offered two approaches for doing so. One scenario, dubbed \u201cGo Big or Go Home,\u201d would develop a space nuclear power system capable of producing 100 to 500 kilowatts of power, which could be incorporated into a propulsion system. This would be a government-led effort with a potential cost of $3 billion.\n<\/p>\n

\nThe second scenario, \u201cChessmaster\u2019s Gambit,\u201d would fund parallel public-private partnerships for smaller systems of between 10 and 100 kilowatts. One track, involving NASA, would focus on a surface reactor that could be used on lunar missions and be later scaled up for Mars. A second track, for the Defense Department, would develop a reactor for in-space applications. Each would cost about $1 billion.\n<\/p>\n

\nIn either scenario, staying on schedule is key. \u201cA 2028 ground test and a 2030 flight aligns with budget cycles, agency leadership terms, and congressional expectations,\u201d she said. \u201cMiss it and we risk stakeholders walking, funding drying up, and competitors defining the future without us.\u201d\n<\/p>\n

\nThe report also included a third scenario, to be carried out in parallel with either of the other two, to develop new radioisotope power systems like the RTGs that NASA has long used for generating power for missions where solar was not an option. This effort would work to bring in new suppliers and use new isotopes, like americium-241 or strontium-90.\n<\/p>\n

\n\u201cOption three is low-hanging fruit,\u201d Lal said. \u201cIt buys time, credibility, and momentum, no matter what, and it provides a fallback if larger efforts slip.\u201d\n<\/p>\n

\nThe report didn\u2019t express a recommendation for either of the two other scenarios, but she said it depends on the level of commitment and leadership. \u201cOption one delivers transformational capability, no doubt, but demands extraordinary alignment and resources,\u201d which she compared to the Manhattan Project. \u201cOption two offers a more executable pathway, grounded in near-term missions and existing agency strengths.\u201d\n<\/p>\n

\nEither scenario is not an end in and of itself, Lal said, but a step towards greater capabilities down the road: \u201cenduring presence on the Moon and Mars, propulsion to Mars, nuclear tugs in Earth orbit, power for peace and projection in contested regimes.\u201d\n<\/p>\n

\n\u201cWe\u2019ve spent 60 years circling this problem. The pieces are finally in shape,\u201d she concluded. \u201cWhat we need now is resolve.\u201d\n<\/p>\n

Jeff Foust (jeff@thespacereview.com<\/a>) is the editor and publisher of The Space Review, and a senior staff writer with SpaceNews<\/a>. He also operates the Spacetoday.net<\/a> web site. Views and opinions expressed in this article are those of the author alone.<\/p>\n

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