(written from a Production point of view)
Sky2 (formerly Sky Two) is a television channel, one of the UK broadcasters of Star Trek. The channel name has been used for two different services, both of which have shown the various Star Trek series.
The first, named Sky 2, was launched in 1996, as a "cult" channel, broadcasting the premieres of shows like Xena and William Shatner's TekWar. The channel also showed first-run episodes of Star Trek: Deep Space Nine and Star Trek: Voyager. However, the station was closed down in 1997 due to poor ratings, and first-run airings moved to Sky One, where they had originally been shown.
The channel name was resurrected in 2005, as a rebranding for Sky One's "timeshuffle" channel Sky One Mix. The channel shows programs previously broadcast on Sky One, and, as of 2007, shows episodes of Star Trek: The Next Generation on a regular basis.