space Propulsion company Fusion pulsar has broken ground on a large nuclear fusion chamber in England, as it races to become the first company to fire a nuclear fusion-powered propulsion system into space.

Nuclear fusion propulsion technology, possibly a space industry cash cow, could cut travel time to Mars in half and reduce travel time to Saturn’s moon Titan to two years in out of 10. Sounds like science fiction, but Pulsar CEO Richard Dinan told TechCrunch in a recent interview that fusion propulsion was “inevitable.”

“You have to wonder, can humanity merge?” he said. “If we can’t, then all of this is irrelevant. If we can, and we can, then fusion propulsion is entirely inevitable. It is irresistible for the human evolution of space. This is happening because the app is irresistible.”

For much of its 11-year history, the Oxfordshire, UK-based company focused primarily on merger research. More recently, Pulsar began developing products that could generate revenue while research continues: a Hall-effect electric thruster for spacecraft and a second-stage hybrid rocket engine. The company has also received funding from the UK Space Agency in 2022 to develop a propulsion system based on nuclear fission, in conjunction with the Nuclear Advanced Manufacturing Research Center and the University of Cambridge.

But for Pulsar, the future of deep space travel lies firmly in fusion propulsion. Fusion for space propulsion is arguably much simpler than fusion for electricity generation here on Earth, in part because the conditions in space (very cold and a near-perfect vacuum) are conducive to fusion reactions. The incredible energy density of those reactions would produce super-fast travel speeds while requiring only a fraction of the fuel compared to existing propulsion systems.

Even if such systems are very expensive, “speed in space is fungible with money,” Dinan said.

“If I can save you X many days in space, I can charge you for that,” he said.

One advantage of this technology, even if it has yet to be demonstrated in a system, is that the underlying physics is well understood: Fusion works in a similar way to our sun, by confining ultra-hot plasma within an electromagnetic field. The difficulty, for scientists, has been stabilizing that plasma for a significant period of time. That’s Pulsar’s next task: building an eight-meter fusion chamber to bring plasma to ultra-hot temperatures and create escape velocities fast enough for interstellar travel.

“The difficulty is learning to retain and confine the super-hot plasma within an electromagnetic field,” Pulsar’s chief financial officer James Lambert explained in a statement. “Plasma behaves like a weather system in terms of being incredibly difficult to predict using conventional techniques.”

The company has already begun construction of that reaction chamber in Bletchley, England. It partnered with New Jersey-based Princeton Satellite Systems to use supercomputer simulations to better understand how plasma will behave under electromagnetic confinement. The pair will also model how plasma would behave as it exits a rocket engine, and that data will help inform Pulsar’s rocket engine design. The next step would be an in-orbit demonstration, where the company would attempt to fire a nuclear fusion-powered propulsion system into space for the first time.

“If we are going to leave our solar system within a human lifetime, there is no other technology that we know of that can do that,” Dinan said.