autrob, you will be able to research UFOs and produce antimatter-fueled interceptors and the like, once you capture one intact UFO. The UFO appear landed as a mission, and you go there, defeat the aliens and take home the captured UFO if you have a suitable UFO hangar. If this happens, you will have the option in the report screen once you win the battle, of destroying or retrieving the captured UFO.
EDIT: the seq_xvi_sentence doubt (also mine) is resolved in another thread.