Project Blue Sky was a weapon research initiative that was sponsored by Starfleet in the 24th century. The aim of the project was the development of a way of killing the Jem'Hadar, the footsoldiers of the Dominion during the devastating Dominion War. In 2374, Starfleet officer Jadzia Dax along with Romulan Subcommander T'Rul were assigned to Project Blue Sky. (DS9 short story: "The Devil You Know")