Project Phoenix

Project Phoenix was a Starfleet operation orchestrated by Fleet Admiral Jean-Luc Picard to create a timeship known as the USS Phoenix which would travel back in time to destroy Bajor before the threat of the Bajoran Ascendancy resulted in the destruction of the universe by the merger of the Blue Wormhole and the Red Wormhole.

(DS9 novel: Millennium The War of the Prophets)