Project Blue Sky was a weapon research initiative sponsored by Starfleet in the 24th century. The project's aim was to develop a method to kill the Jem'Hadar, the footsoldiers of the Dominion during the devastating Dominion War. In 2374, Starfleet officer Jadzia Dax and Romulan Subcommander T'Rul were assigned to Project Blue Sky. (DS9 - Prophecy and Change short story: "The Devil You Know")