British startup Pulsar Fusion is teaming up with the Plasma Physics Lab in Princeton University, USA to develop nuclear-fusion rocket engines. Their Sunbird Project, could halve the current standard travel time to Mars, enabling deep space exploration to be a manifest reality within the next decade. Pulsar Fusion is gearing up fast with financial endowments by the UK Space Agency and private equity firms to work towards slashing the standard seven month journey to a measly three.
The Promise of Fusion for Space Travel
Pulsar Fusion's nuclear fusion plasma engines could dramatically reduce travel times to Mars by achieving much higher speeds than conventional rockets. To put into perspective, the most innovative and efficient chemical engines of today - namely the Raptor 3 engines from Elon Musk's SpaceX utilize cryogenic liquid methane and liquid oxygen, a combination known as Methalox, along with rocket-grade kerosene (RP-1) as propellant. China's space efforts have in contrast made significant strides in developing this technology further.
The key lies in fusion's power - instead of burning methalox, Pulsar's reactors heat mere grams of hydrogen or helium isotopes to over 100 million °C to trigger fusion. That energy is then expelled through supercooled exhausts, generating thrust far beyond what contemporary chemical rockets can deliver.
"It's very unnatural to do fusion on Earth," says Richard Dinan, founder and CEO of Pulsar. "Fusion doesn't want to work in an atmosphere. Space is a more logical, sensible place to do fusion, because that's where it wants to happen anyway", he continued.
Dinan - the former British reality TV sensation, believes this fusion drive could cut the Mars transfer from seven months to just three and a half, as reported by the Houston Chronicle. That shorter journey matters, as Mars resides at a cool 225 million kilometer range from our Earth, with its apogee accounted for. It also dramatically reduces astronauts' radiation exposure during the trip's most perilous phase.
Hybrid Tech on the Way
Sunbird is still in early development. Static ground tests are scheduled for 2025, with an ambitious aim to demonstrate the drive in orbit by 2027. Meanwhile, it has a hefty endowment backed by the UK Space Agency and private investors, plus recent partnerships (like classified U.S. strategic offices in Austin and a MoU with Thales Alenia) to accelerate progress.
Pulsar Fusion's most recent significant strides are in developing Hall Effect Thrusters or HETs, part of their electric propulsion systems. They've successfully developed UK's largest HETs, the 10kW "MarsRanger" and a 25 kW variant on the way - to power satellites. Plasma based engines are highly efficient, using magnetic fields to ionize argon or krypton and eject plasma as thrust. HETs offer high specific impulse, boosting cost efficiency for small crafts, aiding in attitude control, precision manoeuvres, and enhancing satellite orbital lifetimes.
A Renaissance in Advanced Propulsion
Pulsar is part of a broader resurgence in nuclear propulsion interest, albeit operational fusion rockets remain years away from realisation. NASA and DARPA are collaboratively exploring nuclear-thermal propulsion. Rosatom, and the EU remain steadfast with their bleeding edge research in plasma-electric systems. As Dinan puts it: "The space industry is experiencing a renaissance", and sophisticated propulsion will drive the next era of exploration. The British government has recognized the potential of this renaissance, instilling the startup with a grant worth £500,000 in early January of 2025.
Nuclear fusion propulsion may become the foundation of a revived space race, providing a major boost to lunar infrastructure efforts. The Moon harbors an estimated 1 million tons of Helium-3, a rare fusion fuel deposited by the solar wind, making it far richer in 3He than Earth.
Lunar 3He could be a game changer, with its fusion reactions promising clean, efficient energy in powering reactors of the future. Dr. Bhuvana Srinivasan, aerospace engineering professor at the University of Washington (though not affiliated with the Sunbird project), believes this fusion driven propulsion would outperform the existing systems, for both crewed and uncrewed missions in the coming years.
