The Delta IV Heavy is part of a family of rockets that have long served the Department of Defense and NASA.Delta IV Heavy is on the launch pad now at the Cape Canaveral Space Force Station and is ready for its last launch ever. The heavy lift mission will be carrying a payload for the National Reconnaissance Office with launch partners the U.S. Space Force and United Launch Alliance.The swan song for the Delta IV Heavy rocket comes after a decades-long role in mostly secretive surveillance payloads, just like this final mission.Related: Delta IV Heavy: Powerful rocket to take final flight from Cape Canaveral Space Force StationIt’s always a spectacular launch to watch, thanks to 2.1 million pounds of thrust and an interesting quirk that makes it look like the rocket is on fire just before liftoff.“This is one last chance to put up some national security, critical payload for the Space Force, the NRO. So, we are really looking forward to it. Like you say, bittersweet departure of a legacy. But we have Vulcan coming down the road, so we have a big future ahead,” said Ron Fortson, ULA’s director of launch operations.ULA leadership says that the Delta program has played a large role in the creation of its next-generation rocket, Vulcan.And after a successful inaugural launch in January, ULA says the transition from legacy rockets to next-gen will be done seamlessly.Ahead of Thursday’s 1:40 p.m. launch, teams are keeping a very close eye on clouds and ground-level winds.Top headlines: Arrest made after local mother found shot to death, baby found deceased in hot car over 2 years ago Settlement reached in lawsuit between Florida Gov. Ron DeSantis and Disney Delta IV Heavy: Powerful rocket to take final flight from Cape Canaveral Space Force Station