Boom Supersonic fully funds first Symphony engine prototype
December 16, 2024
Boom Supersonic’s latest funding round has bolstered the supersonic airliner developer’s balance sheet with an additional $100 million, which will secure the financing of its first in-house engine prototype.
A ‘down round’ – in which a company offers additional shares for sale at a lower price than the previous round’s sale price – provides an opportunity to raise more money, an option of particular importance to some startups who face a high cash burn rate. “By being flexible on valuation… we created a buying opportunity for investors,” explained Scholl on social media. “This led to oversubscription and leaves the company in a stronger financial position”.
Scholl concluded that “while no founder ever wants to do a recap, [he] remains focused on [the company’s mission” – adding: “Humanity needs and deserves supersonic travel. And I continue to believe boom can be one of the most significant companies of the 21st century”. Major investors in what was effectively a new Series A financing include Alexander Gerko, Bessemer Venture Partners Michael Moritz, Reid Hoffman, Sam Altman and Y Combinator.
Boom Supersonic is pursuing an in-house engine design to power its proposed Mach 1.7-capable Overture airliner, with the purpose-built ‘Symphony’ turbofan to provide up to 35,000lbs of thrust. Boom announced it would be leading the charge to develop its own engine in December 2022.
After unveiling Symphony’s engine architecture at the June 2023 Paris Airshow, the team completed the powerplant’s conceptual design review that October; a key engineering milestone that paved the way for it to start building and rig-testing Symphony hardware. In June 2024, Boom stated that it is making “rapid progress” on the engine’s development, with hardware testing underway. In total, Boom expects to conduct more than 30 Symphony rig tests in collaboration with engine design partner Florida Turbine Technologies (FTT). At the time, Scholl explained that the first full-scale engine core would be operational within 18 months.
Meanwhile, Boom continues to progress with the flight campaign of its technology demonstrator; having recently completed its ninth flight test. One more flight is expected before the Christmas break, where the team hope to reach a new peak speed of Mach 0.9.
“Turns out it is far less painful to make our own engine than try to convince a 100 year old company to move at startup speed,” Blake tweeted yesterday. “Overture and its Symphony engine are being developed together, with everything we learned from XB-1. And that’s where the magic is, developing the whole vehicle together as an integrated system”.
