Currently, humans are limited by transportation problems in their quest to become an interplanetary species. The advance in green technologies that seek to replace polluting energy sources, such as burning fossil fuels, is also making a dent in the field of astronautics. Nuclear fusion is presented as the unequivocal answer to our energy problems, being the cleanest sustainable energy source of all. In addition to decarbonizing the atmosphere and saving the environmental balance, fusion power could take us to new worlds. So a British company is developing a nuclear fusion–based propulsion engine that promises to reduce interstellar travel time to a matter of decades.

Why nuclear-fusion thrusters?

Current propulsion methods present three main problems: One, they are effective in propelling takeoff but not the rest of the aircraft’s trajectory; two, the fuel takes up a lot of space and is heavy; and three, it is polluting the Earth’s atmosphere.

A nuclear fusion booster, like the British company, Pulsar Fusion, is developing, could allow interplanetary and interstellar travel in a fraction of the time compared to our current technology. For example, according to its engineers, nuclear propulsion could take us to Mars in weeks.

Inside a nuclear reactor like the one used by ITER and other entities that investigate this type of energy, the superheated plasma is isolated using an electromagnetic field and subjected to extreme pressure and temperature conditions to preserve its state. As a result, the excited atoms in the plasma squeeze against each other, colliding and fusing into larger atoms. When this happens, a residual amount of energy is emitted from the fusion process. That is the energy that could power our civilization in the future, and why not our space rockets?

Traditional methods of propulsion — chemical propellants — are helpful for takeoff. Still, they cannot provide the spacecraft with thrust once it is underway because the fuel is finished once the spacecraft has escaped the Earth’s gravitational influence. As a result, the thrusters are disengaged from the ship to relieve it of unnecessary weight. This means that the ship will have to visit the vicinity of the Moon or intermediary planets to take advantage of its gravitational momentum to reach its destination.

A fusion drive like the one developed by Pulsar Fusion is called Direct Fusion Drive (DFD). It has the particularity of having a significantly smaller volume than current drives and thousand times their propulsion power. As a result, a DFD can propel the ship during its trajectory permanently, shortening recent space travel times considerably.

The most powerful engine in Europe

The fusion engine designed by Pulsar Fusion and its collaborators will be tested in 2025 when the test prototype is ready, according to an email press release from the company. The company’s engineers consider they can build the fusion-based infrastructure and propulsion systems needed to enable nuclear fusion rockets in less than four years.

The Hall Effect Thruster (HET) is a hybrid electric drive motor developed by Pulsar Fusion. Following its successful trials in Switzerland and the UK in 2021, Head of Operations Dr. James Lambert said: “Pulsar has built and tested the most powerful electric propulsion motors in Europe.”

The engine burns oxid of nitrous oxide (N2O), high-density polyethylene (HDPE) fuel, and oxygen. According to a statement by Richard Dinan, co-founder of the company, in Azo Cleantech, their engine exhaust has less than half the carbon footprint and emissions of greenhouse gases compared to conventional engines.

In addition to releasing less toxic gases into the atmosphere, this propulsion could make the ship reach 20 kilometers per second, more than decent for interplanetary travel.

As always, knowledge is sustained and shared in science based on collective construction and collaboration. Perhaps in our effort to save the planet from the looming climate catastrophe, we will find a way to fuel our fascinating space journeys. On the other hand, perhaps our desire to explore the universe will lead us to establish nuclear fusion as an energy source. Thus, it will recover the balance we have taken from the planet. Either way, Pulsar Fusion’s achievements should be celebrated, as they may soon take us to the stars.