NASA is investigating nuclear electric propulsion as a potential solution to reduce travel time for future missions to Mars. A round trip to the Red Planet currently takes up to two years, raising concerns about astronauts’ prolonged exposure to space radiation and its potential impact on neural and behavioral health. By harnessing nuclear power, NASA aims to shorten this timeframe and improve mission safety.

Modular Design for Space Assembly

Researchers at NASA’s Langley Research Center are leading the Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles (MARVL) project. This initiative focuses on a critical aspect of nuclear electric propulsion: the heat dissipation system. The MARVL concept divides the system into smaller, modular components that can be autonomously assembled by robots in space.

“By doing that, we eliminate trying to fit the whole system into one rocket fairing,” explained Amanda Stark, the principal investigator for MARVL. “In turn, that allows us to loosen up the design a little bit and really optimize it.”

Traditional designs required the entire radiator system—comparable in size to a football field—to fit under a rocket nose cone, a near-impossible task. MARVL’s modular approach enables pieces to be sent into orbit separately, where robots would assemble the radiator panels. These panels circulate a liquid metal coolant, such as a sodium-potassium alloy, to manage the heat generated by the nuclear propulsion system.

Redefining Spacecraft Design

The MARVL project also reimagines the spacecraft assembly process. “Existing vehicles have not previously considered in-space assembly during the design process,” said Julia Cline, a project mentor. “We now have the opportunity to design a vehicle specifically for assembly in space, which could transform how we think about nuclear propulsion.”

Broader Applications of Nuclear Propulsion

The MARVL initiative is supported by NASA’s Space Nuclear Propulsion project, which is advancing technologies for Moon exploration, near-Earth missions, deep space science, and human exploration. This includes both nuclear electric propulsion, which generates thrust by ionizing and accelerating gaseous propellants, and nuclear thermal propulsion, which heats propellants directly for thrust.

These developments aim to revolutionize space travel, paving the way for more efficient and safer missions to Mars and beyond.