Why a Mach 5 passenger plane is a crazy idea that might just work

Atlanta-based startup Hermeus hopes to develop a passenger airplane capable of reaching Mach 5, or 3,000 miles per hour, but is the prospect of building a hypersonic successor to Concorde merely a flight of fancy?
Read more: https://www.cnn.com/travel/article/hypersonic-airplane-hermeus/index.html?source=Snapzu