More meditations on the series
There's a lavish article on the background of Space: 1999 by Michael Richardson.
For further analyzing approach on the series, I suggest you to read the essay written by Alistair McGown;
also commentary on the series, by David M. Welle. Furthermore, there is Petter Ogland's Space: 1999 - a postmodern look at popular television of the 1970s. There are also some essays by Martin Willey. Also, a bit more light-hearted approach at Allscifi Space 1999 Spotlight.
retrofuture.com is an interesting site on past's future fantasies.