Santa Helena is a planet on the Federation-Cardassian border. The Maquis nicknamed it "Destiny".
In 2374, Mexh Brixhta was to meet Tomas Roeder on Santa Helena's third moon, although Luther Sloan and Enderby of Section 31 met Brixhta there instead, as Brixhta had information on Section 31's morphogenic virus that Roeder had planned to take to the Dominion. (DS9 novel: Hollow Men)
In 2376, Rugal Pa'Dar was interned with other Cardassians on Destiny. (DS9 novel: The Never-Ending Sacrifice)