Delta 4

Delta 4-Heavy rocket deploys spysat on final planned mission from ‘Slick Six’

United Launch Alliance sent a triple-core Delta 4-Heavy with a top secret U.S. government spy satellite into orbit Saturday from California’s Central Coast, closing out a chapter in the tangled history of a launch pad originally built to support military astronaut missions on Titan rockets and space shuttles. Two more Delta 4-Heavy rockets are left in ULA’s inventory for launches in 2023 and 2024 from Cape Canaveral.