Falcon HTV-2: The Mach-20 Collide Vehicle General Leave a Comment on Falcon HTV-2: The Mach-20 Collide Vehicle The untold story of DARPA’s HTV-2: a Mach 20 hypersonic experiment that failed spectacularly, reshaped modern weapons, and proved why speed—not stealth—is the future of warfare on Earth today revealed. (Visited 2 times, 1 visits today)