Astral Systems Raises £23M to Tackle Medical Isotope Shortages with Desktop Fusion Reactors

Astral Systems, a Bristol-based deep-tech company, has closed a £23m first close of a Series A funding round led by Mercia Ventures, with co-investors including Tees River, Daphni, Blast Club, Speedinvest, and Playfair Capital . The round brings Astral's total funding to over £28m and is one of the larger fusion-related investments in the UK this year .

A Rare Fusion Company That Already Generates Revenue

Unlike many fusion startups that are still years away from commercial deployment, Astral Systems already operates three commercial fusion facilities with reactors at Technology Readiness Level 9 (TRL9) — the highest level indicating real-world operational deployment . The company has earned over £3m from commercial and research contracts, including a £200,000 research contract with the UK Atomic Energy Authority (UKAEA) .

Its current product line includes the Mk0 MSF reactor (DD: 1×10⁸ n/s; DT: 1×10¹⁰ n/s) and the Mk1, which delivers 10× greater neutron output and 10× longer lifetime than current market alternatives . Both are available for order now. The company's revenue model combines neutron-source research contracts with future B2B medical isotope supply .

Multi-State Fusion: From NASA Research to Desktop Reactors

Astral's core technology is Multi-State Fusion (MSF), a novel fusion approach where reactions occur primarily within a solid-state lattice while also occurring in the plasma . This method is derived from NASA's Lattice Confinement Fusion (LCF) research, which was published in Physical Review C in 2020 and patented by Astral in 2024 .

MSF reactors are remarkably compact — the Mk2 model can fit on an average desk . They produce intense neutron beams that can be used to manufacture medical radioisotopes, directly addressing global shortages that impact cancer diagnosis and treatment . The latest Series A funding will scale reactor deployment and support a first commercial launch of medical isotopes by early 2027 .

Berkeley Power Station: Building the World's Highest-Flux Fusion Neutron Source

Astral Systems has finalised agreements to establish a technology centre at the former Berkeley Power Station in Gloucestershire, a nuclear site decommissioned since 1989 . The company aims to run multiple next-generation compact MSF reactors at full capacity at Berkeley by the end of 2026 . The stated goal is to create the world's highest-flux, highest-intensity, continuously operable private fusion volumetric neutron source .

The facility will support fundamental fusion research, tritium breeder blanket testing, reactor component and subsystem testing, neutron radiography services, and medical isotope production . The broader site redevelopment is envisioned as a "nuclear centre of excellence" by the developer, with Quantum Leap Energy also securing a contract to locate there .

Tritium Breeding Breakthrough: First Commercial Company to Breed Fusion Fuel

In March 2025, Astral Systems achieved a landmark breakthrough as the first commercial fusion company to successfully breed tritium using its own fusion reactor . The achievement was accomplished during a 55-hour neutron irradiation campaign in partnership with the University of Bristol and with support from the UK Atomic Energy Authority (UKAEA) .

Tritium is a critical fusion fuel for deuterium-tritium (D-T) reactions, and the ability to breed it in-house addresses one of the biggest challenges in fusion energy development . The company is now inviting other organisations to participate in neutron irradiation experiments using its MSF DD reactors .

Isotope Production Partnerships

Astral is working with McMaster University in Canada on a fusion-based copper-67 production project, funded by Canadian sources . Canada's Nuclear Isotope Council (CNIC) has accepted Astral as a member organisation . The company is also collaborating with Brazil's Institute for Energy and Nuclear Research (IPEN) to produce Actinium-225 and Lead-212 — isotopes increasingly used in targeted cancer therapies .

By late 2025, Astral expected to begin small batch production of Tb-161 and Cu-64/67, ramping up production through 2026 . In April 2026, the company completed seven distinct neutron irradiation experiments for customers, demonstrating that fusion's industrial utility is already a "today" capability .

A Team with Academic Roots

Astral Systems was founded in 2021 and is headquartered in Bristol . The co-founding team consists of Talmon Firestone and Dr. Tom Wallace-Smith, a University of Bristol Research Associate . No recent technical leadership hires beyond the co-founders were announced in the available sources.

Outlook: Fusion Delivering Value Now

Astral Systems is building a model where fusion delivers value in the near term — solving urgent healthcare challenges, creating jobs, and proving commercial traction — rather than chasing only grid-scale power . With the new Series A funding, the company has the runway to move from a company that has already demonstrated revenue and operational fusion facilities to one that could transform the global supply of medical isotopes.

The sources for this article include the University of Bristol, TechCrunch, the BBC, UKTN, the Nuclear Industry Association, the American Nuclear Society, and NASA, among others.