As the band Europe once sang, it’s the final countdown, at least for United Launch Alliance’s Delta IV Heavy, which is set to retire following its final flight on Thursday, March 28. The classified mission also marks the end of an era that began more than 60 years ago, with ULA bidding farewell to the Delta series.
https://gizmodo.com/ula-delta-iv-heavy-rocket-final-launch-1851363682