The British Business Bank and the government’s defence venture capital fund have backed a $100 million fundraising by the world’s largest space technology investor, capitalising on the buzz around the sector created by the “SpaceX effect”.

The fund is the third to be closed by Seraphim Space since the London-based investment firm started a decade ago.

The private fund has invested in 17 early-stage European and American space tech companies since its initial close in 2024, including Privateer Space, an American space company co-founded by Steve Wozniak, one of the founders of Apple.

It has more than $550 million in assets in its private and public funds, which include Seraphim Space Investment Trust. Shares in the £345 million trust have more than doubled over the past 12 months, making it one of the rare funds to trade at a premium to its net assets.

The National Security Strategic Investment Fund and the British Business Bank have joined investors including Eutelsat, the Paris-based satellite communications provider, and SKY Perfect JSAT, Asia’s largest satellite and pay-TV provider.

A potential blockbuster IPO of SpaceX, Elon Musk’s space exploration company, this year at a potential $1.5 trillion valuation has ignited interest in the space sector among investors.

This month SpaceX said that it had acquired xAI, his artificial intelligence startup, combining the rocket-and-satellite company with the maker of the Grok chatbot in a move aimed at unifying Musk’s AI and space ambitions.

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The merger illustrated the billionaire magnate’s efforts to fuse his fast-growing AI efforts with his aerospace and satellite-internet empire, betting that shared computing, data and engineering talent can accelerate both AI development and potentially support longer-term ambitions for space-based data centres.

Mark Boggett, chief executive of Seraphim Space, said the recent SpaceX–xAI merger was “a clear validation of Seraphim’s long-held view: space tech is fast becoming the foundational enabler for artificial intelligence and digital systems that will power the global economy”.

An increase in defence spending by European governments has also turned the spotlight on sovereign space technology, an area where the continent has lagged behind American and Chinese rivals.

The company has backed 147 early-stage companies, nine of which have achieved unicorn status, including AST SpaceMobile, the Texas-based satellite manufacturer that has formed a joint venture with Vodafone to start a direct-to-device satellite phone service in the UK this year.

Christine Hockley, co-head of funds at the British Business Bank, which committed $20 million in funding, said that in making a cornerstone investment it was “expanding the pool of capital available for the UK’s space entrepreneurs and helping a specialist UK fund manager to thrive”.

The shares rose 5½p, or 3.8 per cent, to close at 151p.