Researchers at NASA are advancing a nuclear-electric propulsion system designed to be delivered in modular components and assembled by robotic systems in space. The concept has been publicly outlined by the space agency as part of ongoing explorations into more efficient deep-space propulsion. By shifting assembly from Earth to space, engineers hope to reduce the mass and complexity of launches while enabling large, high-performance power units to be built in orbit.
Nuclear propulsion relies on a reactor to generate electricity that powers ion engines. Those engines ionize a propellant and accelerate it to produce thrust. The approach offers high propellant efficiency over long-duration missions, making it attractive for journeys beyond the Moon and into the outer reaches of the solar system.
Designs like this require a radiator network to shed heat produced by the reactor and powerplant. For the MARVL concept, the radiator grid is envisioned to be roughly the size of a football field. Fitting such a large structure into current launch fairings and then deploying it reliably in space presents serious engineering hurdles, from stowage to thermal performance and mechanical durability.
MARVL stands for Modular Prefabricated Radiators for Nuclear-Powered Vehicles. The name signals a modular philosophy: large, complex cooling hardware broken into smaller sections engineered to be shipped separately and assembled in space.
The idea is that parts of the system, including the radiator panels and the liquid-metal coolant loops, would be sent in multiple launches and then joined in vacuum. Robotic builders would handle the assembly steps, installing panels, bolting joints, and routing coolant lines to form a fully integrated radiator system in the spacecraft backbone.
NASA envisions that vehicles equipped with MARVL-powered propulsion could undertake missions to Mars and other destinations in the future. The ability to generate substantial electrical power in space could support longer, more capable spacecraft, extended life support, and more resilient communications and scientific instrumentation.
Earlier research has pointed to a core challenge that could limit sustained human activity on the Moon if power and propulsion systems are not robust enough. The MARVL concept addresses part of that challenge by proposing scalable, modular, in-space assembly options that may improve reliability and mission flexibility for deep-space exploration.
While still in the concept phase, MARVL demonstrates how future propulsion architectures might evolve. The modular approach aligns with broader trends in spaceflight that emphasize in-space assembly, robot-assisted construction, and distributed manufacturing. If successful, it could redefine the trade-offs between launch mass, vehicle size, and mission reach.
In the near term, NASA continues to study the physics, materials, and robotics required to make such a system viable. The conversation around nuclear-electric propulsion and modular radiators remains active as engineers weigh heat rejection, radiation shielding, and long-term reliability in the harsh environment of deep space.