America Invested 1.2 Billion Dollars In Two Prototypes Of The XB-70 Valkyrie, Built To Experiment With A 3,000 MPH Machine Which Was Designed As A Predecessor To America's SST. A Disastrous Collision With A Chase Plane Destroyed One Of The Two Valkyries Over California With The Loss Of Two Of America's Top Test Pilots. The Second, Now Retired, Rests On The Tarmac Of The Air Force Museum In Ohio.
