Florian Neukart, an Assistant Professor at the Leiden Institute, has proposed the Magnetic Fusion Plasma Drive (MFPD) as a novel space propulsion method. This concept combines fusion propulsion, ionic propulsion, and more, promising high energy density and fuel efficiency.
Florian Neukart introduces the Magnetic Fusion Plasma Drive, a revolutionary propulsion method combining fusion and ionic techniques. Offering immense energy density and numerous advantages, it could redefine space exploration, although challenges in sustaining fusion reactions in space remain.
Missions to the Moon, missions to
What will it take before human beings can travel to the nearest star system within their own lifetimes? Credit: Shigemi Numazawa/ Project Daedalus
Florian Neukart is an Assistant Professor with the Leiden Institute of Advanced Computer Science (LIACS) at Leiden University and a Board Member of the Swiss quantum technology developer Terra Quantum AG. The preprint of his paper recently appeared online and is being reviewed for publication in Elsevier.
Why the Need for Advanced Propulsion?
According to Neukart, technologies that can surmount conventional chemical propulsion (CCP) are paramount in the present era of space exploration. In particular, these technologies must offer greater energy efficiency, thrust, and capability for long-duration missions.
This is especially true for missions to Mars and other locations beyond the Earth-Moon system, which pose serious risks to astronaut health, safety, and well-being. Even when Earth and Mars are at their closest every 26 months (a Mars Opposition), it can take up to 9 months to make a one-way transit to the planet. Combined with surface operations that could last up to a year and the nine-month return trip, missions to Mars could last up to 900 days! During this time, astronauts will be exposed to elevated levels of cosmic and solar radiation, not to mention the toll of long periods spent in microgravity will have on their bodies.
Hence,
Artist's depiction of the IKAROS spaceprobe ( the first spacecraft to successfully demonstrate solar sail technology in interplanetary space) in flight. Credit: Andrzej Mirecki Solar Sails are another option, which can generate continuous acceleration while requiring no propellant (thereby saving on mass). However, missions equipped with this technology are limited in terms of thrust and must operate closer to the Sun. A twist on the idea is to employ Gigawatt-energy (GWe) laser arrays to accelerate spacecraft equipped with sails to relativistic speeds (a fraction of the speed of light). However, this concept requires expensive infrastructure and tremendous amounts of power in order to be feasible. Another popular concept is nuclear thermal propulsion (NTP), which NASA and
A spacecraft powered by a positron reactor would resemble this artist's concept of the Mars Reference Mission spacecraft. Credit: NASA There are also propulsion concepts that harness fusion reactions, like Deuterium-Tritium (D-T) and Deuterium-Helium three (D-He3) reactions, something that theoretical scientists have been working with for decades. These methods offer the potential for high thrust and extremely high specific impulse but also present technical challenges, not the least of which are related to handling the necessary fuel and achieving sustained and controlled fusion reactions. There are also more exotic concepts, like antimatter propulsion and the Alcubierre Warp Drive, but none of these will be available in the foreseeable future. And there's Neukart's proposal, which combines elements of fusion propulsion, ionic propulsion, and other concepts. As he explained to Universe Today via email: “The MFPD is a propulsion system for space exploration, utilizing controlled nuclear fusion reactions as a primary energy source for both thrust and potential electric power generation. The system is predicated on harnessing the immense energy output from fusion reactions, typically involving isotopes of hydrogen or helium, to produce a high-velocity exhaust of particles, thereby generating thrust according to Newton's third law. “The
Artist's concept of a Bimodal Nuclear Thermal Rocket in Low Earth Orbit. Credit: NASA To develop this concept, Nuekart began with deuterium-tritium (D-T) fusion reactions since it is one of the most researched and understood reactions and offers a clear and familiar basis for elaborating the core principles and mechanics of MFPD. Furthermore, Neukart added, D-T reactions have relatively low ignition temperatures and a higher cross-section than other concepts, making it a good “starting point.” Therefore, they provide a useful benchmark for measuring and comparing the performance of this theoretical propulsion system. However, the ultimate goal of MFPD is to harness aneutronic fusion (p-B11), where very little of the energy released by the reactions is carried by neutrons. Aneutronic reactions, in contrast, release energy in the form of charged particles (typically protons or alpha particles), thereby significantly reducing the level of neutron radiation produced. The advantages of this system are immediately apparent, combining high specific impulse and immense energy density and providing both thrust and power from a single energy source. Other benefits, said Neukert, include the following: As to the implications this system could have for space exploration, Nuekart emphasized the ability to traverse vast cosmic distances in reduced timeframes, expanding mission profiles (fast transits to other planets in the Solar System and interstellar missions), mitigating the risks of long-duration space missions (exposure to radiation and microgravity), revolutionizing spacecraft design by providing propulsion and electrical power simultaneously, and enhancing human exploration capabilities. Beyond that, he also foresees the potential for technological spin-offs in materials science, plasma physics, and energy production that could have applications here on Earth. The development of this system could also foster international collaborations, bringing experts and resources from multiple fields together to realize common exploratory objectives. Of course, no next-generation technology proposal would be complete without some caveats and addendums. For instance, said Nuekart, the main challenge for MFPD propulsion lies in achieving and maintaining stable fusion relations in space. On Earth, researchers have made considerable progress with magnetic confinement (MCF) and inertial confinement fusion (ICF). The former involves Tokamok reactors using magnetic fields to confine fusion in the form of plasma, while the latter relies on lasers to compress and heat tablets of D-T fuel. However, similar experiments have not been conducted in space, leading to questions about how the system will handle heat caused by reactions, the resulting radiation, and the structural implications for spacecraft. Nevertheless, the ball is already rolling on nuclear tests in space (the aforementioned DRACO demonstrator). Given the benefits of fusion propulsion, it's not likely to remain on the drawing board for long. Ultimately, says Nuekart, the research into MFPD aims to establish a pathway that will lead to interplanetary and (someday) Interstellar exploration: “While the journey to realize the MFPD concept will undeniably be layered with challenges and scientific hurdles, the potential payoff is monumental. Achieving reliable, effective, and efficient fusion propulsion could redefine the boundaries of achievable goals, propelling humanity into a new era of exploration, discovery, and understanding of the cosmos. The hope is that the research seeds curiosity, innovation, and determination among scientists, engineers, and explorers across the globe, charting the course toward our future among the stars.” Adapted from an article originally published on Universe Today. Reference: “Magnetic Fusion Plasma Drive” by Florian Neukart, 20 September 2023, Physics > General Physics.
Nuclear and Fusion Propulsion
Neukart's Revolutionary Concept
Advantages of MFPD
Implications and Challenges
arXiv:2309.11524
