NASA announces plan for space nuclear propulsion by 2028

Yesterday NASA announced a series of initiatives, including plans to launch a nuclear electric propulsion spacecraft to Mars in December 2028 and a three-phase plan to establish a lunar base incorporating nuclear-driven heat and power.

These announcements follow a December 2025 executive order with a range of space-related mandates, including the return of Americans to the moon by 2028, the establishment of lunar outpost elements by 2030, an increased launch cadence, and growth of the commercial space economy.

After a full day of announcements, NASA Administrator Jared Isaacman said at a news conference, "Everything really we discussed today was in response to President Trump's executive order on American space superiority."

First nuclear-powered rocket: NASA's announced plans include launching Space Reactor-1 Freedom, a nuclear electric propulsion rocket, to Mars in December 2028.

The high efficiency and energy density of nuclear propulsion-both thermal and electric- has made its deployment a long-standing goal for space travel. In a presentation streamed yesterday, Steve Sinacore, fission surface power program executive at NASA, said that over 60 years, NASA has spent more than $20 billion on more than a dozen attempted flight programs. SNAP-10A, NASA's only flight reactor to have made it to space, stopped working after 43 days due to a nonnuclear component failure.

Sinacore said that SR-1 Freedom differs from previous attempts by limiting its scope to using existing technology, where the reactor is the primary new system. This approach prioritizes hitting the 2028 Mars launch window.

"The scope must bend around this deadline," he said. "This will be the first mission in a sustained cadence, not a one-off. . . . It is a pathfinder, not the blueprint."

Isaacman described SR-1 Freedom as a "70 percent solution to prove that it works."

Sinacore added that the team has not decided if SR-1 Freedom will fly by or enter Mars orbit.

"The team is still looking at exploring the opportunities. Once we drop off Skyfall what do we do with SR-1 Freedom?" he said. (Skyfall is one piece of the mission, consisting of delivering three helicopters for Mars exploration.)

SR-1 Freedom specs: Sinacore said that the SR-1 Freedom reactor will turn on within 48 hours after launch and will take approximately one year to reach Mars.

Key specs include:

Approximately 20-kWe reactor with HALEU uranium oxide fuel, thermal transfer through heat pipes, and boron carbide radiation shield.

Advanced closed Brayton cycle power conversion system to convert reactor heat into electricity.

Heat rejection system featuring high-performance, lightweight composite and titanium radiators.

Spacecraft thrusters with an advanced electric propulsion system of up to 48 kW. This element will be repurposed to provide the spacecraft bus, which will include the communication systems, power management and distribution, and a potential payload.

Mission details: This mission aims to perform Mars-relevant science and transmit footage to Earth, which is where the Skyfall triad of helicopters comes in.

Nicola Fox, associate administrator for the NASA science mission directorate, said the helicopters will be "very, very similar in capability to Ingenuity," the helicopters that demonstrated the first powered flight on Mars in 2021 and completed 72 flights there over nearly three years.

"Think those kinds of distances they can travel," Fox said. "They will have some capabilities. They will have cameras on them to be able to take images, but they're not going to be full-up heavy science birds."

Sinacore said, "The Skyfall helicopters will carry cameras and ground-penetrating radar to scout a future landing site to understand the slopes and hazards for human-scale landers. They will also map and characterize the subsurface water ice to find out where the water ice deposits are, along with the size, depth, and other important characteristics."

Sinacore laid out an ambitious timeline, planning for significant design to be complete and hardware development to begin in June 2026, all spacecraft assembly and testing to occur between January and October 2028, and SR-1 Freedom to be launched in December 2028.

To the moon: Sinacore explained that Lunar Reactor-1, which is planned for 2030, will be informed by SR-1 Freedom data and lessons learned.

"In the 2030s we will scale up and move into production" of further reactors, Sinacore said. "We're talking hundreds of kilowatts to megawatt-class reactors for all nuclear applications. Higher-powered missions to the moon, human missions to Mars, with commercial participation and repeatable production."

Meanwhile, NASA is pausing its Gateway Program, which sought to establish a space station in lunar orbit, in favor of focusing on the development of a permanent moon base.

"Every asset, every kilogram, all the lunar exploration resources that we have are going to be focused on one thing, and that is to build the moon base," said Carlos Garcia-Galan, deputy manager for the Gateway Program, who also spoke during the NASA livestream.

Garcia-Galan's new role is program executive for the moon base project. He said a key goal is exploring the lunar south pole, including interest in the bottom of the Shackleton crater and other areas that are nearly or completely permanently shadowed-so while solar power is part of the plan, nuclear power is an essential component for surviving the lunar night.

"Anything we can do to not rely necessarily on solar power and allow the assets to get heating and maybe some power is going to be golden for our ability to take that forward," said Garcia-Galan.

Moon base timeline: The agency has laid out a stepwise plan to accomplish the lunar base in three phases.

Phase one (2026-2028) includes about two dozen launches that will deliver around 4,000 kg of payload to the lunar surface, according to Garcia-Galan. This phase will also include a crewed mission to the moon through what he describes as a drastically expanded version of the Commercial Lunar Payload Services (CLPS) initiative. He describes phase one as a "very challenging timeline."

Garcia-Galan said there will be a $10 billion investment in phase one, which will test a range of systems including the VIPER rover, lunar terrain vehicles, drones, navigation systems, orbital communications relays, and radioisotope heater units.

Phase two (2029-2032) will begin establishing lunar infrastructure, delivering around 60,000 kg of payload over 27 launches and two crewed missions per year, with another $10 billion investment. Garcia-Galan said this phase will include building out hundreds of watts of nuclear surface power capability using radioisotope thermal generators.

Phase three (2033-2036) will deliver around 150,000 kg of payload to the lunar surface across 29 launches, supported by a more than $10 billion investment. The plan is to establish habitable volumes across multiple sites to enable a continuous human presence and have systems in place to support a four-crew, 28-day lunar mission.

Garcia-Galan said, "The fission surface power program is scheduled to deliver something on phase three for more capacity, and maybe more than one thing, for the capacity that we expect we'll need for the moon base."

When asked if programs would need to be cut to pay for the moon base, Isaacman said they will be drawing on a lot of resources from Gateway, including repurposing technology.

"You're basically looking across the various mission directorates and making sure that if you have a component and resources that they contribute towards one of the major objectives in the president's national space policy, like the moon base," he said.

Dragonfly ongoing: According to NASA, Dragonfly, a car-sized, nuclear-powered rotorcraft, is still on track to launch in 2028. It will traverse Saturn's moon Titan for over three years collecting and analyzing samples and exploring various geological sites with the goal of understanding the chemical origins of life and investigating the moon's habitability.

Dragonfly passed its critical design review in April 2025, and on March 10 of this year, NASA announced that integration and testing were underway for the rotorcraft.

"It will be the first science vehicle to explore multiple locations on another world, performing vertical takeoffs and landings in search of evidence of prebiotic chemical processes and other signs of habitability," said Fox. "Because it can fly through Titan's dense atmosphere, Dragonfly will be able to travel much farther in a much shorter time than even our most capable vehicles on Mars."