SpaceX is preparing to launch back-to-back Falcon 9 rockets on Sunday from both California and Florida.The Starlink 12-23 mission from Cape Canaveral Space Force Station is set to follow the Starlink 11-9 mission from Vandenberg Space Force Base.Liftoff from Space Launch Complex 40 is targeting 10:58 p.m. EDT (0258 UTC).SpaceX is also planning to launch another Falcon 9 rocket Sunday night on the Starlink 11-9 mission from Vandenberg Space Force Base.