On Tuesday, April 14, 2015, SpaceX’s Falcon 9 rocket and Dragon spacecraft lifted off from Launch Complex 40 at Cape Canaveral Air Force Station in Florida, beginning SpaceX’s sixth official mission to resupply the space station for NASA. The launch occurred at 4:10pm EDT and while weather had remained a concern during the countdown, Falcon 9 executed a picture-perfect liftoff into a nearly cloudless sky.
According to Elon, after the first stage broke off the throttle valves were sticking, which caused the computer to control out of phase. Essentially a hardware issue was causing the physical side of the controls to lag. Ultimately this caused the failed landing attempt and subsequent explosion.