Hypersonic startup Hermeus has confirmed the successful completion of the first flight of its Quarterhorse Mk 1 demonstrator.
Although the feat was not publicly announced until May 27, 2025, the flight took place a few days earlier at Edwards Air Force Base, California
The Quarterhorse Mk 1 is a clean-sheet unmanned aircraft which will serve as the basis to develop a family of high-speed and even hypersonic aircraft, capable of flying at speeds in excess of Mach 3, or faster than three times the speed of sound.
In a social media post, Skyler Shuford, the founder and President of Hermeus, highlighted that the Quarterhorse Mk 1 has taken just 19 months to get from the drawing board to its first flight. According to the aerospace entrepreneur, this is the fastest development time for a jet aircraft in the last eight decades.
We are now an airplane company.
At ~19 months from clean sheet to first flight, including 5 months of sitting in the hangar waiting on paperwork, this makes @hermeuscorp:
The fastest clean sheet development of a jet in the last 79 years (MiG-9), and 4th overall (P-59, P-80,… https://t.co/WN1NWnrbPE
— Skyler (@skyshuford) May 27, 2025
Hermeus takes pride in the agility of its development process, which involves a fast iteration from one prototype to the next. A new model called Quarterhorse Mk 2, capable of reaching high supersonic speeds, is already in the works and is expected to fly before the end of 2025.
Larger and faster hypersonic designs have already been sketched for development over the longer term for both military and civilian applications. In particular, the US startup is working on a multi-mission unmanned aerial system (UAS) concept called “Darkhorse” and an airliner called “Halcyon”, both of which are capable of reaching hypersonic speeds.
As of May 2025, Hermeus, which is based in Atlanta, Georgia, has raised more than $100 million, including investments from defense conglomerate Raytheon Technologies and well-known technology investors Sam Altman, CEO of OpenAI, and Khosla Ventures, co-founder of Sun Microsystems, among others. Hermeus has also received funding from the US Department of Defense through research and development programs run by its Defense Innovation Unit (DIU).
