United Launch Alliance’s Delta IV Heavy rocket will make its first launch in over 19 months Thursday, carrying out a clandestine mission to deploy a surveillance satellite for the National Reconnaissance Office. Liftoff is expected between 02:12 and 06:16 Eastern Daylight Time (06:12-10:12 UTC), from the Cape Canaveral Air Force Station in Florida. Thursday’s mission, designated NRO Launch 44 (NROL-44), marks the first Delta IV mission since the Medium+ variant of the rocket was retired in August 2019 and the first Delta IV Heavy since January 2019. Although ULA is phasing out the Delta IV in favour of its Vulcan...