This is a vision straight out of Star Trek.
A UK startup called Pulsar Fusion has unveiled plans for a spacecraft engine that would use nuclear fusion as its core propulsion system, which could dramatically accelerate interplanetary travel.
Unlike nuclear fission used in some older spacecraft, which splits atoms to generate energy, fusion mimics the high-energy reactions inside stars, combining light atoms like hydrogen to form heavier ones, releasing immense power in the process.
“Fusion doesn’t want to work in an atmosphere,” said Richard Dinan, Pulsar’s founder and chief executive, told CNN.
“Space is a far more logical, sensible place to do fusion, because that’s where it wants to happen anyway.”
NASA has long estimated that a crewed journey to Mars would be a roughly three-year round trip.
The global race to Mars is led by SpaceX and NASA, with Elon Musk’s private enterprise aiming for uncrewed Starship launches as early as 2026, likely followed by manned missions as early as 2029. The government-backed NASA targets crewed missions in the 2030s.
Among the five core hazards outlined by NASA’s Human Research Program, distance from Earth poses challenges that affect every facet of a Mars mission.
These include communication delays of up to 20 minutes each way, prolonged exposure to space radiation, limited access to medical intervention, and no chance of quick return in the event of an emergency, as stated on NASA’s website.
A propulsion breakthrough like Pulsar Fusion’s, if realised, could help mitigate these risks by easing the distance factor.
How the science works
On Earth, creating fusion energy requires enormous temperatures —hotter than the surface of the Sun— and powerful magnetic fields to contain the resulting plasma, a soup of charged particles.
Decades of research have yet to produce a net-positive energy yield. But Pulsar believes that space itself, with its vacuum and extreme conditions, may offer a more natural setting for such reactions.
The idea is to build a rocket which emits a “nuclear exhaust,” expelling charged particles at extraordinary speeds to propel the spacecraft forward.
Dubbed “Sunbird,” this rocket would be powered by helium-3, a rare and costly isotope thought to be plentiful on the Moon but scarce on Earth.
Dinan envisions orbital “charging stations” where fusion-powered craft could dock and refuel, akin to interplanetary gas stations.
“You turn off your inefficient combustion engines, and use nuclear fusion for the greater part of your journey,” he tells CNN. One hub might orbit Earth, another near Mars, with Sunbird rockets ferrying between them.
Each Sunbird would measure around 100 feet and be wrapped in armor-like plating to shield against cosmic radiation and micrometeorite impacts, according to Live Science.
With an estimated cost of $90 million apiece —due largely to the helium-3 fuel— these would be no ordinary spacecraft.
The timeline is ambitious. The company hopes to conduct a small-scale fusion test in orbit by 2027, using what it calls a “linear fusion experiment” to validate key systems.
A fully operational prototype, the company suggests, could follow within five years, assuming funding remains intact.
Global race
First theorised in the 1920s and demonstrated in laboratories by the 1930s, nuclear fusion has long captivated scientists as the force that powers the Sun.
For nearly a century, it has been pursued as a near-limitless source of energy —cleaner, safer, and more sustainable than nuclear fission, yet vastly more difficult to control.
In recent years, however, fusion research has entered a new phase —one defined by intensifying global competition.
In 2024, the US government allocated approximately $790 million for fusion science programs, as noted during a Fusion Industry Association (FIA) conference.
China, meanwhile, invested an estimated $1.5 billion annually in fusion research —nearly double the US government's commitment that year.
In January 2025, China’s Experimental Advanced Superconducting Tokamak, or EAST, often dubbed the “artificial sun”, set a world record by sustaining plasma temperatures exceeding 100 million degrees Celsius for over 1,000 seconds.
If successful, the British startup's Sunbird rocket could position the UK as a serious contender in the fusion race, marking a turning point in space exploration.
