I haven't been able to do this. I can build an Orbital "Launchpad?" but cannot send units to the moon! (I use a Earth and Moon map) How do i accomplish this?
Build an Astreus, which can pick up one unit at a time (a builder, usually) to cart to the desired planet. Load the unit, and with the Astreus selected, go to the other planet's view and use "S-Move" to go there, then unload.
It also works by rightclicking on target planet surface (you must zoom in for this). But you can only carry fabricators and commanders for now. That's why orbital is still kind of broken since its extremely hard to attack a fortified planets, specially if there are no moons to smash.
The Orbital Launcher isn't what sends units to other planets. You must build the Astreus, as has been mentioned. It's a unit that sends commanders or fabricators to other planets.
I have built the Astreus, I just haven't been able to switch to the other planet's view. And how would I go about "smashing planets"?
"," and "." to switch planet views smashing planets = build some halleys. In the system view you can see a list of planets and how many halleys are required to smash.
You can also use the scroll whelk to switch between planets. And here's a planet smashing tutorial. http://pamatches.com/2013/how-to-destroy-planets-with-the-halley/