Astromechanica founder Ian Brooke raises funding to build supersonic hybrid-electric aircraft starting with unmanned DoD platforms

Summary

Ian Brooke is building supersonic hybrid-electric aircraft at Astromechanica, a company that began in a San Francisco machine shop and has now closed a funding round led by a16z with early backing from LowerCarbon Capital, whose partner Shiao wrote the first institutional check when Brooke was still working alone on his first prototype.

Brooke's background shapes the entire thesis. He built his first plane at 17, was doing experimental drones in the early 2000s before the category existed, and came to the hybrid-electric architecture through the private jet world, initially chasing lower operating costs. The unexpected finding was that the architecture also unlocks a path to supersonic flight — specifically a transition into what he calls ramjet mode, which delivers high performance at relatively low system cost. The company is often mistaken for an engine company, but the engine was a prerequisite, not the product. The round now shifts focus to aircraft development.

The roadmap

The flagship civil target is the world's first non-stop transpacific supersonic aircraft — California to Taiwan, under four hours, no refueling. The market Brooke is after is closer to NetJets than to Boom Supersonic's airline ambitions.

The next seven to ten years, however, will be DoD and unmanned. The logic is straightforward: making something fly is not hard; making it safe enough to carry passengers is enormously expensive to prove. By starting with unmanned military platforms, where capability matters before safety certification, Astromechanica can run faster iteration cycles, accumulate flight data, and surface failure modes at lower cost. Brooke develops new engines every four months and explicitly draws the parallel to SpaceX's Starship approach — aggressive hardware cycles, accept losses early, lock in learnings before costs compound. The Waymo analogy also fits: years of operation without passengers before the safety driver comes out.

The unmanned aircraft being developed are not small — Brooke describes them as starting at $20,000-class platforms. The DoD path is also the revenue path that funds the eventual civilian program.

Fuel and efficiency

For civil applications, Brooke plans to move away from jet fuel entirely, adopting liquid natural gas on the model of the rocket industry. Swapping to LNG delivers roughly 30% less CO2 as a direct fuel substitution, and LNG carries more energy per unit weight — 50 megajoules per kilogram versus 42 for jet fuel. Combined with the engine architecture efficiency gains, Brooke estimates around 60% lower CO2 versus conventional supersonic flight. LNG is also approximately a tenth the price of jet fuel, so the economics case comes before the environmental one. Longer term, the same engine architecture is well-suited to synthetic electrofuels if and when those become cost-competitive.

The China-Boeing sidebar

Asked about China's cancellation of Boeing orders and the COMAC C919's prospects, Brooke is skeptical China can replicate Western engine technology in the near term. The C919 still uses American engines, and he draws the analogy to TSMC — the airframe is tractable, the propulsion is not. Commercial aviation reliability is the harder problem: the CFM56, which powers 50 to 60% of narrow-body airliners, can stay on wing for nearly 30,000 hours. That kind of proven durability takes decades to accumulate and is not obvious at entry — even Pratt & Whitney is still working through issues on its geared turbofan years after launch.