Nuclear-electric propulsion technology could accelerate missions to Mars

The round trip to Mars is not for the faint of heart. We are not talking about days, weeks or months. But there are technologies that could help transport a crew on that round trip in a relatively quick two years.

One option being explored by NASA is nuclear power propulsionwho employs a nuclear reactor to produce electricity that ionizes, or positively charges, and electrically accelerates gaseous thrusters to provide thrust to a spacecraft.

Researchers at NASA’s Langley Research Center in Hampton, Virginia, are working on a system that could help bring nuclear electric propulsion a big, game-changing step closer to reality.

Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles, or MARVL, aim to take a critical part of nuclear electric propulsion, its heat dissipation system, and break it down into smaller components that can be assembled robotically and autonomously in space.

“By doing this, we eliminate the attempt to integrate the entire system into a single rocket fairing,” said Amanda Stark, a heat transfer engineer at NASA Langley and principal investigator of MARVL. “In turn, that allows us to relax the design a little bit and really optimize it.”

Making the design more flexible is essential because, as Stark mentioned, previous ideas called for installing the entire nuclear electric heater system under a rocket fairing, or nose cone, that covers and protects a payload . Fully deployed, the array of heat-dissipating radiators would be about the size of a football field. You can imagine the challenge engineers would face to carefully fold such a massive system inside the tip of a rocket.

MARVL technology opens up a world of possibilities. Rather than cramming the entire system into an existing rocket, this would give researchers the flexibility to send pieces of the system into space in the most logical way and then assemble it all off-planet.

Once in space, the robots would connect the radiator panels of the nuclear electric propulsion system, through which a metallic coolant, such as a sodium-potassium alloy, would flow.

While still a technical challenge, it’s exactly the kind of technical challenge that space assembly experts at NASA Langley have been working on for decades. MARVL technology could mark an important first step. Rather than being a complement to existing technology, the in-space assembly component will benefit and influence the design of the spacecraft it will serve.

“Existing vehicles haven’t yet considered assembly in space during the design process, so here we have an opportunity to say, ‘We’re going to build this vehicle in space.’ “And what does the vehicle look like if we do that? I think it’s going to expand what we’re thinking about in terms of nuclear propulsion,” said Julia Cline, the project’s mentor in the research directorate. of NASA at Langley, who led the center’s involvement in the development of technological maturation plan for nuclear electric propulsion as a precursor. at MARVL. This technology maturation plan was executed as part of the agency’s Space Nuclear Propulsion project at the Marshall Space Flight Center in Huntsville, Alabama.

NASA’s Space Technology Mission Directorate awarded the MARVL project under the Early Career Initiative, giving the team two years to advance the concept. Stark and his teammates are working with an external partner, Boyd Lancaster, Inc., to develop the thermal management system. The team also includes radiator design engineers from NASA’s Glenn Research Center in Cleveland and fluid engineers from NASA’s Kennedy Space Center in Florida. After two years, the team hopes to move the MARVL design toward a small-scale ground demonstration.

The idea of ​​robotically building a nuclear propulsion system in space sparks the imagination.

“One of our mentors remarked, ‘This is why I wanted to work at NASA, for projects like this,'” Stark said, “which is great because I’m so happy to be there be involved and I feel the same way. “

Additional support for MARVL comes from the agency’s Space Nuclear Propulsion project. The project’s ongoing efforts aim to advance technologies for operations around the Moon and near-Earth exploration, deep space science missions and human exploration using nuclear electric propulsion and nuclear thermal propulsion.