VM
The now offline website Sub TV had a whole page about the ITV satellite tests. The short story: they started tests on 26th October 2001, with the proper launch on 21st November. ITV2 appeared the next day.
Worth reading through the whole page though:
http://web.archive.org/web/20060213220636/http://www.sub-tv.co.uk:80/dsat/itvtests.asp
Worth reading through the whole page though:
http://web.archive.org/web/20060213220636/http://www.sub-tv.co.uk:80/dsat/itvtests.asp