A Titan 4B rocket is set to launch into space Wednesday, marking the final flight of a Titan 4 rocket. Set to launch a classified payload for the U.S. National Reconnaisance Office (NRO), the Titan 4B booster is set to liftoff from California's Vandenberg Air Force Base sometime between 12:00 p.m. and 4:00 p.m. EDT (1600-2000 GMT) on Oct. 19. The Titan 4 rocket family, built by Lockheed Martin, debuted in 1989. This week's flight, set to lift off from Space Launch Complex 4E, has been delayed since 2003. ============================================ Still America's most powerful unmanned booster -- at least for...