User blog comment:Braveangel/About planetary defenses/@comment-217683-20100429192115

Indeed. Just because the Ascension was the most formidable dreadnought in Citadel space doesn't mean it could stand up to an assault (however brief) by a massive group of smaller ships.

Now that the plot hole/not plot hole thing is resolved, I may have to go back and re-watch some BSG. I don't recall seeing any armed platform above Caprica. The only Colonial orbital facility I recall seeing was the Scorpia shipyards. And given that it was an embedded virus (or whatever) in a new navigation program (specifically the Command Navigation Program), I don't see how any orbital facilities would be affected. Finally, like I said, I could be wrong, and I need to go back and re-watch it to find out for sure, but I found some pretty decent images on the Battlestar wiki (such as http://en.battlestarwiki.org/wiki/File:Bsyashuman.jpg which shows Battlestars over Caprica surrounded by Vipers), and don't reall see anything that could be an orbital defense station, nor does the Battlestar wiki note the existence of any such facilities.