Hmmm then I guess I must have missunderstood:
"IMPORTANT CAMPAIGN INFO:
The FreeSpace 2 campaign is the one enabled by default. If you want to start from the very beginning of the FreeSpace 1 campaign (and I see no reason why you wouldn't) then you need to use the "MOD" tab on the launcher and select the original campaign using the instructions below:
Simply click "Select mod", select "fsport-mediavps" folder from the list, and click "OK". Then start the game, create a new pilot, go to the
Campaign Room and select the FS1 main campaign. Voila. When you are done with the original campaign and want to try "Silent Threat: Reborn", follow the instructions in this thread. Note that you should have ST:R already installed so there's no need to download anything. When you're done with both of those and want to play the daddy, FS2, then simply change your current mod folder to "mediavps" from the Launcher, as we've done before."
Taken from the idiots guide in the general discussion....
Could anyone please clarify this?
And thanks for the other answers!
EDIT: Ahh I get it now I think, the FS1 campaign that's only for singleplayer right?