RTX Ventures, a capital investment group recently set up by Raytheon Technologies [RTX], on Thursday said it made a strategic investment in the start-up company Hermeus Corp., which is developing hypersonic aircraft for commercial and defense applications.

The value of the investment wasn’t disclosed but is part of a $100 million Series B financing round announced in March that is led by investor Sam Altman and includes Founder’s Fund, In-Q-Tel, Khosla Ventures, Canaan Partners, Bling Capital, and the seed fund Revolution’s Rise of the Rest.

Hermeus said the funding round will allow it to finish development of its first aircraft, Quarterhorse—a remotely piloted aircraft scheduled to fly in 2023—begin flight services operations, and accelerate development of Darkhorse, an uncrewed aircraft that can sustain hypersonic flight. Work on Darkhorse will help the inform development of Halcyon, the company’s commercial passenger aircraft.

“Hypersonic technologies are of critical national 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,” Daniel Ateya, managing director of RTX Ventures, said in a statement. “Hermeus’ 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.”

In addition to the funding, the RTX Ventures investment gives Hermeus access to Raytheon Technologies’ thousands of engineers, development centers, mentors and business leaders.

RTX Ventures aligns its investments with Raytheon Technologies technology focus areas, with an emphasis on secure and connected ecosystems, autonomy and artificial intelligence, power and propulsion systems, and precision sensing and effects.