How do I blockade?.

[Strategia_In_Ultima]

Just use cloaking devices. While cloaked, park your fleet above the enemy planet, then decloak. Without a fight, you'll have a blockade. Or, you could use a SYS with no weapons at all and move it to a defenseless planet, then build a single sat or something else that's done in 1 turn, move the SYS away and voila, a blockade.

[Slick]

I'm pretty sure that units like satellites and fighters can't blockade a planet. Have you tested this method?

[Frederick_d_Ohlmann]

Mine can't, I'm sure. For the other unit I think they can, but I may be wrong