That would be the punchline for a kids joke. As a dad joke, it subverts the expected punchline with something even cheesier.
Signal reception
reception is a play on words, in an actual wedding it would mean the that the attendees had a good reaction. In the sense that the newly weds are satellites, the reception can also refer to radio signal reception.
Did you hear about the two satellites that got married?
The wedding wasn't much, but the reception was incredible.
Should the punchline be "out of this world"?