Cambridge Aerospace was just valued at $3.4 billion, less than two years after it was founded — and the two numbers that would let anyone test that valuation, the price of one Skyhammer and the size of its UK contract, have never been published as figures

Cambridge Aerospace announced on August 10 that it had raised $300 million at a valuation of $3.4 billion, led by DFJ Growth with support from Lux, Accel, Lakestar, Never Lift, Ora Global and Elad Gil & Co. The company was formed in 2024. Its Series B closed only four months earlier, at $200 million and a $1.3 billion valuation, which makes this a 2.6-fold markup in four months.

The business behind that number is narrow and specific. Cambridge Aerospace builds Skyhammer, a modular low-cost interceptor with a range of 30km and a maximum speed of 700km/h, designed to shoot down Shahed-style attack drones. A second product, Starhammer, aimed at faster and higher-value missiles, is not due to market until 2027. The company also lists a multistatic radar system called Looking Glass and a solid rocket motor line called Nightstar. Skyhammer is the one with a customer.

That customer is the reason the valuation is arguable rather than absurd. It is also the reason nobody outside the deal can check it.

What the public record actually contains

The Ministry of Defence has published five items that touch this company, and the sequence matters more than any one of them.

On March 18 the department listed Cambridge Aerospace among thirteen UK-based defense companies whose representatives met Gulf ambassadors and defense attachés at a London roundtable on industry support for regional allies.

On April 10, opening the London Defence Conference, then Defence Secretary John Healey said the MoD intends to buy Skyhammer missiles and launchers for the UK Armed Forces and Gulf partners. The release hedged where it mattered: the first tranche was promised “subject to contract,” and the deal was described only as “multi-million pound,” set to include integration, technical support and end user training. Chief executive Steven Barrett said Skyhammer had been designed to bring “affordable mass.”

On May 1 the MoD said that contract had been signed less than two weeks earlier, and that Skyhammer had been tested in Jordan in demanding desert conditions at one of Deep Element’s defense development facilities, with Minister for Defence Readiness and Industry Luke Pollard watching. Multi-million-pound again.

On May 17, in a release mostly about a different weapon, the department referred back to the deal as a signed multi-million-pound contract. Second confirmation of a signature, second time without a number.

On July 13 the MoD awarded £3.16 million to three suppliers, Frankenburg Technologies, Greenjets and Cambridge Aerospace, to develop low-cost interceptors under the Low-Cost Air Defence Effectors programme, the UK’s national slice of a five-nation European effort that also involves Poland, France, Italy and Germany. The release does not say how that money divides between the three.

So the only pound figure the MoD has ever attached to Cambridge Aerospace is £3.16 million, shared with two other companies. The contract that actually matters to the business has been announced, signed, and referred back to, and quantified never.

The public record holds one more document about this company, and it is not about missiles. On May 19 the Independent Adviser on Ministerial Standards, Sir Laurie Magnus, published his correspondence with Sir Grant Shapps, who co-founded Cambridge Aerospace with Barrett and carried the title of chairman from November 2024 until April 30 this year. Shapps was Defence Secretary until July 2024, and his appointment had been cleared on the understanding that the company was civilian, on condition that he “must not work in, or advise on, defence matters.” Magnus concluded that Shapps had “allowed a perception of impropriety to develop,” had neglected to seek fresh advice as the role changed, and had “failed to uphold the standards expected in the Rules.” Shapps says he had no involvement of any kind in the Ministry of Defence contract, that despite the title he was not a company director and held no voting rights, and he has apologized for not seeking updated advice sooner.

His account also names the route the purchase took. Shapps describes being “only abstractly aware that an Urgent Operational Requirement process was nearing completion,” the Ministry’s mechanism for buying at speed. Contracts Finder, the government’s register of award notices, returns nothing for Skyhammer, for the Low-Cost Air Defence Effectors programme, or for any of the three suppliers. The figure is not merely unannounced. It was never entered where award values normally sit.

Why “cheap” is the most valuable word in air defense right now

The market Cambridge Aerospace sells into exists because of an arithmetic problem its customers cannot solve by buying more of what they already own.

The July release put the scale plainly: in March 2026, Russia launched the equivalent of more than 200 drones per day into Ukraine. Meeting that volume with conventional interceptors gets expensive in a way that compounds. A CSIS analysis of Russian long-range strike, published in February 2025, estimated each Shahed at $35,000 per drone, with its authors noting that estimates vary. The same paper put a Patriot PAC-3 interceptor at “over 3 million dollars” and a NASAMS round, an AIM-9X variant, at “slightly over 1 million dollars.”

Firing the second at the first is not a trade any defense ministry wants to make nightly. That gap is the whole commercial thesis, and every investor in the August round is buying a claim about where Skyhammer sits inside it.

Cambridge Aerospace has never published that claim as a figure, though it has pointed at a band. At DSEI in 2025 Barrett put Skyhammer’s cost in the tens of thousands of dollars, and coverage of the April order quoted him placing it on a par with a Shahed drone at £20,000 to £30,000. Barrett has said the interceptors are “not only cost-effective but also highly capable.” The company’s own framing, repeated in trade coverage, is that unit pricing runs at one to two percent of conventional interceptor costs. None of that is a price. Reporting the April order, The Aviationist wrote that no exact cost per unit for Skyhammer is known, and no specific figure appears in any company release, any Ministry of Defence document or any parliamentary answer.

Where this could be wrong

A private valuation is a price two sets of lawyers agreed on, not a measurement. DFJ Growth’s Randy Glein said the firm “surveyed the global landscape and identified Cambridge as having the best team and technology to build the most advanced and modern air defense infrastructure for Europe and its allies,” which is a statement of conviction from someone who has just taken a position in the company. It is evidence about the investor.

The government record is also messier than the timeline implies. The July award release states that Cambridge Aerospace “has only recently been identified to the Ministry of Defence, demonstrating the value of widening access to new market entrants.” The same department had named the company in a press release four months earlier and had a Defence Secretary announcing plans to buy its missiles from a conference stage three months earlier. The likeliest explanation is that a production purchase and a development competition ran through different parts of a large organization and were written up by different hands. It is a wrinkle in the public account rather than a resolved contradiction, and none of the documents settles it.

The CSIS figures deserve their date, too. They were published in February 2025, and the paper itself says the underlying data “was not specific enough for cost-exchange calculations,” which is exactly the calculation a low-cost interceptor pitch depends on. They are good for orders of magnitude and nothing finer.

What is verified is solid enough. The contract is signed, the interceptor was tested in Jordan under ministerial observation, deliveries were scheduled to begin in May, and the company reported more than 250 employees in August, two-thirds of them in technical and engineering roles, across the UK, Germany, Poland, Norway, Ukraine and Australia. The April announcement had said the deal would create over 50 jobs and support 125 existing ones, which is a different measure from total headcount, so the two figures are not a clean before-and-after.

Defence Secretary Wes Streeting called the valuation “a great vote of confidence in Britain” and tied it to a government scheme meant to turn defense startups into billion-pound companies. On his own framing the scheme is working, though Cambridge Aerospace is not among the thirteen firms that actually hold contracts under the unicorn fund. Whether the interceptor is cheap enough to change the exchange rate that made it fundable is a separate question, and the answer sits with the company and its customer, neither of which has published a figure.