Why should NASA go all-in on nuclear propulsion?
By Ross Pomeroy | Published: 2025-10-15 17:56:00 | Source: The Present – Big Think
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Watch it from orbit, Jackass Apartments – It is located in southern Nevada, about 65 miles northwest of Las Vegas – and could easily be confused with Mars. The alluvial basin is filled with dark brown and grey, slightly reddish regolith, and is almost entirely surrounded by sculpted rocky hills. Here, half a century ago, NASA engineers tested nuclear rockets that were intended to take us to the Red Planet by 1978.
Officials had higher hopes for the descendants of those missiles. She was Planned to be mules for a permanent lunar base by 1981, propulsion systems for deep space probes to Jupiter, Saturn and the outer planets, and engines for “space tugs” and shuttles that transport payloads and people from low Earth orbit (LEO) to space stations around the Earth and the Moon. NASA even envisioned a The “Grand Tour” of the Solar System Propelled by nuclear rockets, taking advantage of the planetary alignment that occurs every 174 years to visit Jupiter, Saturn, Uranus and Neptune in one comprehensive mission between 1976 and 1980.
Why did this glorious space future not materialize? What went wrong? Well, nothing. In fact, these missiles have been tested amazingly well.
“The Rover/NERVA program conducted during the 1960s was a very successful technology program,” according to NASA. Contractor report It was praised in 1991. “Its goals and objectives were to demonstrate the feasibility of a nuclear rocket engine system for space applications. This ‘proof of concept’ program was mission-oriented and culminated in the successful demonstration of a ground-based test engine system.”
The nuclear missiles were almost ready to be launched into Earth’s orbit for the next stage of testing. Then everything changed.
Why don’t we have nuclear propulsion now?
Short story: America won the lunar space race. After that, public attention quickly turned again to mundane affairs: the end of the Vietnam War, record inflation, and the oil crisis. Politicians have favored cost-cutting over expensive space adventures. In January 1973, the Nixon administration abruptly canceled the NERVA program, the nuclear engine for rocket vehicle applications, after 17 years of research and development and spending nearly $10 billion in 2025 dollars. The Space Shuttle program became NASA’s primary focus. It turned out to be a successful project, but certainly more local.
Nuclear propulsion gradually received federal funding and attention over the following decades, but nowhere near what it enjoyed in the 1960s. There was the Timberwind project in the 1980s, the space thermal nuclear propulsion program in the 1980s and 1990s, the Prometheus project between 2003 and 2006, and most recently the DRACO program between 2023 and May of this year. All projects were eventually cancelled.
Bhavya Lall — a professor of policy analysis at the RAND School of Public Policy and a former NASA associate administrator for technology, policy, and strategy — recently co-authored a report that calculates government spending on nuclear propulsion and explores why programs fail.
“The United States did not fail to deploy nuclear systems in space because we lacked the physics, funding, or people,” she said. He said At a Space Business Roundtable event in Washington in July. “What we didn’t have was mission appeal, institutional cohesion, and a sense of scale.”
In other words, every government program focused on developing nuclear propulsion was a side project. These missions are vulnerable to cuts when politicians look to cut spending. But despite decades of false starts, the case for nuclear power remains strong.
The issue of nuclear transformation
Nuclear space propulsion Comes in two flavours: Nuclear thermal rockets and nuclear electric propulsion (NEP). In thermonuclear rockets, a small nuclear reactor heats propellant — often liquid hydrogen — to extreme temperatures of thousands of degrees. Then, just like a traditional chemical rocket, this propellant is converted into a hot gas and expelled from the nozzle, propelling the rocket forward. Nuclear thermonuclear rockets have about twice the fuel efficiency of chemical rockets, and they also have a fair amount of thrust. Not as much as chemical rockets, but more than enough to propel a spacecraft into the solar system once the craft is in space.
NEP, on the other hand, uses a nuclear reactor to electrify the thrusters that provide the motive power. These thrusters produce small amounts of thrust compared to chemical or nuclear thermal missiles, but are up to 20 times more efficient than conventional missiles. This means they can accelerate the spacecraft for much longer periods, trading on slower starts for increased efficiency and range, making transit times comparable to other options. A spacecraft equipped with nuclear electric propulsion could also use its nuclear reactor to power the entire mission. And in space, where collective efficacy is everything, this could be a game-changer. Bhavya Lalprofessor of policy analysis at the RAND School of Public Policy and former NASA associate administrator for technology, policy, and strategy, explained in an article interview With space news.
“The energy density is so high that you could do a mission to Mars with uranium the size of a marble,” she said. “But beyond that, there’s no way to do a lot of science without nuclear power. A few years ago, we went to Pluto on the New Horizons mission. The probes went quickly past Pluto. Why? Because we didn’t have delta V to go into orbit… all we had was basically 24 hours’ worth of data. So we get a lot more value for our money if we have nuclear power.”
Almost all spacecraft sent into deep space — including the Voyager, Juno, Cassini-Huygens, and Galileo probes — must perform gravity-assist maneuvers, slingshotting around planets to gain speed for their expansive journeys. These circuitous approaches significantly extend mission duration and limit launches to narrow windows. Nuclear propulsion could free spacecraft from these constraints.
NASA comprehensive nuclear energy
So why not make nuclear propulsion the main focus at NASA instead of a side project? Before his nomination to lead the space agency was unceremoniously nixed earlier this year as collateral damage of President Donald Trump’s breakup with Elon Musk, Jared Isaacman intended to do just that. Entrepreneur, aviator, and commercial astronaut, who was widely viewed as an excellent choice to lead NASA, Planned To make nuclear electric propulsion one of its defining issues.
“I believe the best way to boost morale and inspire the next generation is to ‘Get Big Things Done!’: return American astronauts to the Moon, create an architecture for routine and affordable missions, and lay out a reliable path to Mars,” Isaacman told Big Think in an email. “NEP has an important role to play in this. It also properly calibrates NASA to focus on the ‘nearly impossible’ — the kind of work that other agencies or companies can’t do or don’t have the business case to warrant.”
in Editorial Published in August at Real Clear ScienceIsaacman teamed up with 2012 presidential candidate and former Speaker of the House Newt Gingrich to argue that NASA should build a fleet of new-powered spaceships, writing that this is “something no other agency, organization, or company can accomplish.”
“If America wants to lead, NASA must once again confront the hard problems and do the nearly impossible. It must urgently deliver the systems it can build—leaving routine operations like Earth-to-orbit delivery to the healthy commercial launch industry,” Isaacman and Gingrich wrote.
To make room in the budget for this bold endeavor, the duo called for cuts to the behind schedule and budget Space Launch System (SLS), an ultra-heavy lift rocket intended to return astronauts to the moon using the Artemis program. After 14 years of development and Nearly $30 billion was spentIsaacman explained that the missile was launched successfully only once in 2022 Big thought NASA should orbit SLS only after achieving initial lunar goals.
“At some point, we will need to move from a disposable $4 billion rocket to something more sustainable for recurring lunar missions.”
In an email interview, Gingrich did not mince words to express his negative view of SLS.
“The Space Launch System is hopeless, but it survives by pig barrel pressure,” he said.
Open the solar system
NASA’s pioneering work in chemical rocketry paved the way for the now thriving private industry in the United States, opening Earth’s orbit to business. A new focus on nuclear propulsion could open up the solar system itself.
“The commercial launch industry is healthy and will continue to reduce the cost of placing large volumes in low Earth orbit,” Isaacman said. “We can then take advantage of NEP to efficiently move mass to the Moon, Mars and beyond. Think of it like a transcontinental railroad — not the fastest way to move a lot of mass, but certainly the most efficient.”
“In the future, NEP could be the enabling technology for keeping cryogenic propellants cool on deep space missions, providing energy in areas where solar energy is less useful, enabling surface propellant fabrication on Mars for return missions, and even supporting commercial applications such as asteroid mining,” he added.
For Gingrich, this nuclear push is not just an aspiration; It is an existential necessity. For more than half a century, it has been taken for granted that the United States and its democracy dominate space. There are an increasing number of experts now warning And that China and authoritarianism could seize that leadership within the next decade.
“We are on the verge of freedom or communist totalitarianism leading the way into space,” Gingrich told Big Think. “It is historically important that freedom leads the way and sets the rules.”
According to another ReportsTrump may be reconsidering his decision to nix Isaacman’s nomination to lead NASA, so a leading advocate of nuclear propulsion may soon take the helm of the world’s leading space agency.
Isaacman told Big Think that he wants to see a change in routine at NASA.
“The status quo at the agency is not working — and that is clear in every Inspector General report. This is not the time for stagnation as China looks to surpass America’s leadership on the high ground in space. We need to challenge the status quo, recalibrate around NASA’s true mission and get back to making history. The country needs NASA and the world needs NASA. And I want to see the agency get back to making discoveries that change the world.”
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