The Plumbers' Research Satellite Delta is a training facility for soon-to-be Plumbers.
It first appeared in Above and Beyond when Max Tennyson tricked the Plumbers' Helpers into thinking that he was being attacked by Ben while he was really trying to improve them and work as a team so they could be Plumbers. When Manny Armstrong and Rath were fighting, they broke something that caused the satellite to almost crash into London, England. At the end of the episode Max prevented this from happening and then promoted the Plumbers Helpers to official Plumbers.
Ben 10: Alien Force
- Above and Beyond (first appearance)