Hmm. Don't know what to tell you -- as others have said, there's no in-game cheat for it, just a mod. It almost sounds like you might have a glitch to me, as I have had my own Sim abducted like 3 times without even trying. My Sim is female, and an astronaut, not a scientist. She has an alien roommate who is a scientist and they do have a satellite antenna but I have not used it to contact the aliens.
Interaction with aliens seems to help. The last abduction came after my Sim went out on a date with a guy who turned out to be an alien. He reached 'Very Flirty' on the date and started glowing, so she 'discovered' him. Shortly after that, she went exploring space, returned, and was abducted as soon as she exited her rocket.
My Sim's house/yard is decorated with all the goodies she's brought back from her space missions, so there are space rocks, alien life forms and so forth on the lot, which I assume may boost the chance of abduction. But it sounds like you have all that too.
ETA: I wonder if the Sim's attitude toward aliens plays into things at all? (No idea, just wondering.) One thing I noticed is that my astronaut Sim is definitely considered 'pro-alien' by the game, I guess. When she discovered her date was an alien, she didn't get angry, she got a positive 'xenophilia' (or something like that) moodlet.