it's called the x-51a waverider.he air force research laboratory, it's a do-or-die flight. the x-51 had flown three times before. >> we have a booster burnout. >> with one partial success and two duds. >> it was always scheduled to go into the ocean, but not after just 30 seconds. >> everybody knows this has to be perfect. >> on their fourth try, the team get exactly what they're hoping for -- the longest flight ever with a new engine that can fly one mile in one second. big ben and the big apple would be only an hour apart at that speed. >> we have the technology in hand to be able to design and build an engine that can fly in that extreme environment for however long we can carry fuel. if we had more fuel, we could have flown further. >> today's jet engines have trouble going faster than two or three times the speed of sound because their rotating parts would get too hot. but the engine that powered waverider had virtually no moving parts. it's called a scram jet engine. here's how it works. air from outside the ai