BLETCHLEY, U.K. – Pulsar Fusion in Bletchley, England, has demonstrated “first plasma” in the exhaust system of its Sunbird propulsion concept. This marks an early step in the development of a fusion-based rocket architecture for deep-space missions.
The test showed how the system can confine and guide plasma within the exhaust channel using electric and magnetic fields. The company focused on validating the physical layout rather than measuring full performance.
Pulsar Fusion carried out the experiment at its U.K. facility and streamed the results to an audience of researchers, engineers, and industry leaders during a technical session at the MARS Conference in California.
Related: Pulsar Fusion partners with UKAEA on Sunbird fusion propulsion modeling
Initial testing and measurement plans
For the initial series, the team used krypton as a propellant because of its ionization properties and stable behavior at lower flow rates. Future tests will add radio-frequency systems and rotating magnetic fields to increase plasma energy and improve measurement accuracy.
Pulsar Fusion also plans to collect more data in the next phase, including thrust and exhaust velocity. Engineers will use diagnostic tools such as E×B probes and retarding potential analyzers to characterize plasma behavior under different operating conditions.
The company is working with the U.K. Atomic Energy Authority to study how neutron radiation could affect components over time, particularly magnets and structural materials exposed to high-energy particles.
Advancing fusion propulsion concepts
Fusion propulsion remains an experimental area, but it aims to address limitations in current systems. Chemical rockets provide high thrust but limited exhaust velocity, while electric propulsion offers efficiency with lower thrust. A fusion-based approach could combine both characteristics, potentially reducing travel times for missions across the solar system.
