The history of hypersonics teaches that faith in, and unquestioning acceptance of, a hypersonic future is akin to belief in the Second Coming: one knows and trusts that it will occur, but one can't be certain when. That hypersonics is yet again in a period of renewal echoes a familiar theme in the history of hypersonic research and development. As programs have waxed and waned, the field has progressed through various cycles of growing interest and rising optimism followed by cancellation, pessimism, and slow rebuilding of interest. For example, at the time the first two volumes of The Hypersonic Revolution: Case Studies in the History of Hypersonic Technology were published, it appeared that the field was, at last, on the verge of achieving what had been its most long-sought goal: developing hardware--a genuine transatmospheric vehicle, the X-3O, that could take off from the earth under its own power (using air breathing propulsion) fly through the atmosphere into space, and then return through the atmosphere to land, and possible complementary European and Asian vehicles as well.