https://www.wired.com/story/the-rocket-motor-of-the-future-breathes-air-like-a-jet-engine/
When Davis founded Mountain Aerospace Research Solutions in 2018, no one had ever made a working air-breathing rocket engine before. NASA and aerospace giants like Rolls-Royce had tried, and all the projects fizzled out due to soaring costs and major technological challenges. But Davis, a former Aviation Ordnance technician in the Marines, had an idea for an air-breathing engine of his own and couldn’t shake the idea.
