Hermeus, a startup focused on defense aviation, has recently raised $350 million to further its mission of building unmanned hypersonic fighter jets. This funding comes on the heels of two successful flight demonstrations, which showcased the company's innovative technology. With this financial boost, Hermeus plans to take a significant step forward in its next flight, aiming to achieve supersonic speeds—meaning they want to fly faster than the speed of sound.

The development of hypersonic figh...