Wait a few days and De-Legro might be able to say "yes".
I think the only way to assault one is to have some padding on your fleet, so whatever your force is you have an equal or more amount of scouts. That way there is a chance that the scouts are hit instead of your fighting force.
I've seen Jahoren or whatever his name is take several defended planets, but no idea what fleet he used to do it. I've been advised to build a fleet with a few powerful ships and then tons of cannon fodder, no idea if that will work.
