This assumes you're jamming very close to the dish. The trouble with jamming is you have to deal with the inverse square law so you really can't deny very much area. If they have a fleet of hundreds of high power modern directional jammers they could degrade this or other networks, but they're just not going to have that kind of sophistication.

Oh, I was thinking of jamming the receivers of the satellites. Should have written it explicitly, it is indeed not clear.