Fusion propulsion has been proposed for decades as a highly efficient way to move spacecraft faster across the solar system without the need for massive amounts of fuel. Making that concept a reality has, however, proved difficult, especially when it comes to controlling plasma and directing it into usable thrust.
At Amazon’s MARS Conference in California, Pulsar Fusion demonstrated “first plasma” in its Sunbird exhaust test system, with the experiment conducted in Bletchley, UK, and streamed live to the stage.
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The test showed plasma being confined and guided through the exhaust architecture, offering a first look at how a fusion-powered propulsion system might work outside of theory and simulation.
A reusable space tug in orbit
Chemical rockets provide strong bursts of thrust but burn through large amounts of propellant, while electric systems stretch fuel efficiency but accelerate slowly over long periods.
Fusion propulsion is attractive because it offers the possibility of combining high thrust with extremely high exhaust velocity, something current propulsion systems cannot deliver at the same time.
Pulsar’s Sunbird concept takes aim at that trade-off by acting as a reusable space tug operating in orbit.
Instead of launching spacecraft with large amounts of chemical propellant, a lighter vehicle could dock with the tug and receive the push needed to reach destinations such as the Moon.
Internal modelling suggests that approach could reduce in-space propellant requirements by more than 90% for missions similar to Artemis II.
The recent plasma milestone is still an early-stage result, but it provides a clearer view of how fusion propulsion hardware could evolve from laboratory experiments into practical spacecraft systems.
I wanted to find out more, so spoke with Pulsar Fusion CEO Richard Dinan about the technical hurdles ahead, the economics of fusion propulsion, and how systems like Sunbird could reshape future missions.
- What breakthroughs has Pulsar Fusion achieved in order to deliver this first successful demonstration of plasma control?
The breakthrough here was not a single moment, but the successful integration of several difficult elements into one working system.
We were able to generate plasma within the exhaust structure and demonstrate that it could be guided and shaped using electromagnetic fields in a propulsion-relevant architecture.
That matters because controlling plasma is fundamental. Before you can talk seriously about higher-energy systems, you first have to show that you can create the flow, contain it, and direct it in a stable and measurable way.
This demonstration was an early but important step in proving that the architecture behaves as intended.
That matters enormously in space, because every kilogram of propellant launched from Earth is expensive. A high-Specific Impulse propulsion system can dramatically reduce the amount of fuel that must be carried for deep-space maneuvers.
- Specific Impulse will be a new concept for our audience. Can you describe why this metric is so important and how an Artemis mission based on plasma technology would differ in terms of fuel carried, risks, and CAPEX/OPEX?
In an Artemis-type architecture, that could mean a very different mission design. Instead of relying entirely on chemical propulsion launched from Earth in one go, you could imagine lighter spacecraft being delivered to orbit and then transferred onward by highly efficient in-space propulsion systems.
That changes the fuel equation, reduces dependence on brute force launch mass, and opens the door to reusable orbital infrastructure.
This ultimately means lighter launch craft, and therefore less fuel and less weight, resulting in faster, cheaper, more efficient missions.
- You argue that a shift away from single-launch delivery mechanisms to a reusable (and therefore cheaper) model lies in our common future. Can you tell us more about your vision and what sort of price point you predict, given that Orbital predicts $10/kg?
Our view is that the future of space will look less like single-use expeditionary missions and more like a transport network.
Today, most missions still depend on launching everything needed for the mission in one stack, from one gravity well, at one moment in time. That is expensive and inherently inefficient.
We think the long-term future is an orbital economy built around reusable infrastructure: vehicles that move cargo, fuel, and eventually strategic assets between orbits and beyond, without being discarded after one mission.
That does not just reduce cost, it changes what becomes commercially possible. Once mobility in space becomes reusable, you can start treating propulsion as an operational service rather than a disposable hardware event.
- One of the facts you mentioned surprised me. Sunbird delivers megawatt-scale onboard power. How does that happen? What sort of energy ranges (in MWh) are we looking at, and what use cases does it unlock?
It's an important point that a fusion-based propulsion architecture is not only interesting because of thrust. It is also interesting because, in principle, it is tied to very large energy flows. That means a mature system could potentially support both propulsion and substantial onboard power availability.
At this stage, however, we would be careful to distinguish between long-term system potential and what is being demonstrated today.
The present work is about validating elements of plasma control and exhaust architecture, not delivering a flight-ready power platform.
In the long run, if such systems mature as hoped, megawatt-class onboard power could unlock a very different category of spacecraft capability, including deep-space operations, power-hungry payloads, and entirely new classes of orbital and interplanetary missions.
- How did Pulsar Fusion achieve what looks like a major breakthrough in propulsion while titans (SpaceX, NASA) haven't yet cracked it? What is the secret sauce, and how do you plan to keep abreast of the competition?
I would be careful with the framing. We are not claiming to have solved fusion propulsion in its entirety, and there is still a great deal of work ahead.
What we have done is move quickly and show early progress in a specific architecture that we believe has long-term promise.
Large organizations often have different incentives. They may be focused on near-term operational systems, legacy architectures, or broader institutional priorities. Smaller companies can sometimes move faster in frontier areas because they are willing to concentrate their effort on a narrower technical pathway.
- You mentioned nuclear fusion space propulsion in your March 2026 press release. How is that different from the "holy grail" represented by the tokamak?
A tokamak is designed first and foremost as a terrestrial fusion power machine. Its job is to confine plasma for long enough, at sufficient temperature and pressure, to produce useful net energy in a stationary power-generation context.
A space propulsion system has a very different objective. It is not simply trying to replicate a grid-scale fusion plant in orbit. It is trying to create a system in which high-energy plasma can ultimately be used for propulsion in a mass-constrained, mission-driven environment.
So while both involve plasma physics and fusion-related principles, the design logic is very different.
One is optimized for stable power production on Earth; the other is being pursued as a propulsion architecture for space, where efficiency, mass, controllability, and exhaust behavior are central.
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