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 ...

Boeing has selected mach 5.0 as the top speed for a hypersonic passenger jet because that greatly simplifies the structural materials and the propulsion. Standard titanium alloys used in aircraft and ...

Hermeus said it won the contract after designing, building, and successfully testing a prototype of an engine capable of propelling an airplane to Mach 5, or five times the speed of sound ...