ZDC Controller reported a session in which Florida traffic had to go over 180 miles off shore due to traffic volume and a rocket launch.

Narrative

I got a position relief briefing for DIW-R side. Before getting the briefing I was informed that Jacksonville Sectors Summer and Georgetown were not accepting any south Florida traffic (MIA; FLL; and PBI). If the aircraft were able to go over 180 miles off shore they could be routed through Metta and Knemo Jacksonville sectors; this requirement due to a planned Rocket Launch as well as thunderstorms to the south. However; not all aircraft were able make it down the AR's with that requirement. When I got the sector; aircraft going to south Florida were on northeast headings to hold in an area away from the rest of the traffic. The EDST (En-Route Decision Support Tool) was at a full page. The previous R-side worked the D-side. In order to get control of the sector I called Georgetown and told them I was unable to take northbound traffic. I gave them the option of routing though another sector. The previous Controller told [Center Sector] they could not hold any more south Florida traffic. W122 was active so we had less airspace to work with. Once I got control of the sector; I figured out which aircraft could take the over water routing and started routing those planes that direction. Then I told [Center] they could move some of their holding south Florida traffic to the south. I also called Georgetown and told them they could run traffic northbound again. Numerous aircraft ended up diverting for fuel reasons. Jacksonville was overwhelmed with volume. The traffic management initiatives in place were not working for the volume with the weather and rocket launch. Aircraft should have been kept on the ground to avoid getting Jacksonville to a breaking point. It was an unsafe situation for my sector and all the sectors around me to be put into a no notice hold. It was a huge logistical nightmare for the users and we were providing them no service by letting them get airborne. I saw many aircraft took off; were holding near their origin just to divert back to the same airport. A review of the decisions made as well as the process in which to make these decisions need to be addressed.