Key Points and Summary – The SR-71 Blackbird delivered unmatched Mach-3 recon, but its costs proved fatal. -Each flight hour ran $200,000–$300,000, driven by extreme maintenance, heat-damaged coatings ...

Lockheed Martin’s SR-72 “Darkstar” aims to fly at Mach 6, pairing hypersonic reconnaissance with strike options such as the High-Speed Strike Weapon. -But a 2025 prototype flight, as reported in the ...