Hypersonic aircraft developer Hermeus continues to attract major investors, this time through a partnership with Raytheon Technologies Venture Capital Group. Raytheon’s recently established RTX Ventures is making a “strategic investment” to help Hermeus complete its first hypersonic aircraft, Quarterhorse, which is a remotely-piloted small vehicle. The support also will help expedite development of Darkhorse, which will be used to mature technologies for its planned 14-seat business aircraft, Halycon.

Hermeus has begun flying Quarterhorse in simulation with in-house avionics hardware and flight software, it reported. This simulation, using what it called “hardware-in-the-loop,” will help de-risk avionics for Quarterhorse, testing software throughout the flight profile up to Mach 5, Hermeus said. The testing will simulate Quarterhorse flight conditions in real-time, calculating vehicle state in all degrees of freedom. In addition to testing nominal flight conditions, the company is also stressing the system with anomalies and varying model parameters to build confidence in the software.

Powered by Hermeus’s turbine-based combined cycle engines, based on the GE J85, Quarterhorse is anticipated to fly in 2023, testing speeds of between Mach 3 and Mach 5.

“Speed is our lifeblood at Hermeus, and I’ve been impressed with the ability of the team at RTX Ventures to embody that virtue. We look forward to expanding collaboration and continued acceleration of our vision for a faster future,” said Hermeus CEO AJ Piplica.

The RTX Ventures investment, the amount of which was not specified, joins a $100 million Series B financing round Hermeus announced in March that was led by entrepreneur Sam Altman and brought in new investors Founder's Fund and In-Q-Tel (a strategic investor to U.S. Intelligence agencies).

Raytheon founded RTX Ventures to invest in early-stage companies and accelerate “transformational” technologies. “Hypersonic technologies are of critical importance to national security, which is why we made our first investment in a company with such a bold plan and vision in this space,” said Daniel Ateya, managing director of RTX Ventures. “Hermeus’s technical approach and business plan balances near-term defense applications with long-term commercial aspirations and will help our customers reimagine the possibilities of hypersonic technologies.”