Ever since the sound barrier was broken, people have been asking: "Why can’t we break the light speed barrier too, what’s the big difference?" It is too soon to tell if the light barrier can be broken, but one thing is certain -- it’s a wholly different problem than breaking the sound barrier. The sound barrier was broken by an object that was made of matter, not sound. The atoms and molecules that make up matter are connected by electromagnetic fields, the same stuff that light is made of. In the case of the light speed barrier, the thing that’s trying to break the barrier is made up of the same stuff as the barrier itself. How can an object travel faster than that which links its atoms? Like we said, it’s a wholly different problem than breaking the sound barrier.
Read this excellent article along with the links embedded in it from the following location:
NASA - Status of "Warp Drive"