From Napkin Sketch to Mars: A New Bimodal Nuclear Rocket Design
- Space nuclear propulsion experts at NASA and General Atomics are proposing a synchronal bimodal nuclear engine that could halve the transit time for human missions to Mars.
- Long transit times present a severe hazard for crewed interplanetary spaceflight due to intense cosmic radiation and microgravity.
- While the concept offers significant advantages over conventional chemical systems, the proposed rocket engine remains in the early paper-planning stage.
Space nuclear propulsion experts at NASA and General Atomics are proposing a synchronal bimodal nuclear engine that could halve the transit time for human missions to Mars. According to IEEE Spectrum, the conceptual rocket design merges mature electric propulsion with nuclear thermal propulsion to reduce the health risks associated with long-duration interplanetary travel.
Merging Mature Technologies for Faster Interplanetary Transit
Long transit times present a severe hazard for crewed interplanetary spaceflight due to intense cosmic radiation and microgravity. According to IEEE Spectrum’s Special Projects Editor Stephen Cass, once you get outside the Van Allen belts, there’s so much natural radioactivity—that’s the real killer.
Traditional chemical rockets require lengthy cruise phases, keeping human crews exposed to these hostile environments for extended periods.
To address this hazard, Kurt Polzin, chief engineer of the space nuclear propulsion project at NASA’s Marshall Space Flight Center, collaborated with Robert Schleicher of General Atomics Electromagnetic Systems. The two engineers met at a conference last year and did the classic let’s-sketch-out-an-idea-on-a-napkin,
Cass notes. Their resulting bimodal nuclear engine design is intended to simultaneously provide power and propulsion, cutting the travel time to Mars in half.
Engineering Challenges on the Drawing Board
While the concept offers significant advantages over conventional chemical systems, the proposed rocket engine remains in the early paper-planning stage. Cass points out that this rocket engine is still at the paper-planning stage, which, to be fair, is where most of NASA’s humans-to-Mars planning has been for the last 60 years.
The design relies on combining existing aerospace components rather than inventing entirely new physics. According to Cass, they’re pulling together a lot of fairly mature technology.
Electric propulsion systems are already well understood and mature, whereas nuclear thermal propulsion requires further development. The new part is merging them together, and that of course throws up its own challenges,
Cass explains.
Moving From Napkin Sketches to Public Discussion
The preliminary design has now moved from its initial sketch phase into public view in IEEE Spectrum’s recent issue, accompanied by illustrations from John MacNeill. The publication invites engineers, researchers, and space enthusiasts to review the proposal and contribute feedback. The whole point of the article is to say, ‘Here’s our napkin. Noodle on this with us and tell us what you think,’
Cass says. Readers can submit their responses through the journal’s online comment section or via mail.
