24 launchers 120 per minute (more with sprayed rockets) with return loop for unused rockets
24 launchers (8x3) for 120 rockets/min. This design takes advantage of the launcher pass-thru feature to provide a return path back to the tower for storage.
When framework construction is complete, shut off the tower rocket feeds to the launchers, set the tower to supply, and bump up the maximum. All unused rockets will return to the tower. No clean up. Combined with a proper rocket retrieval system on your rocket producing planet, all rockets will return to their point of origin automatically (with tower set to remote supply), except for the very last load. (If your rocket retrieval system has a minimum load of 100 on its vessels for example, the last 99 would never be picked up. Take those home, yourself.) I leave my retrieval tower min load all the way down, and they all get picked up.