Delta IV Heavy

Company: United Launch Alliance

The Delta IV Heavy uses two additional Common Booster Cores (CBCs) as liquid rocket boosters in place of the GEM-60 solid rocket motors that power the Delta IV Medium variants. The Delta IV Heavy is composed of a central CBC. Only one RS-68 engine is used by each CBC. The Delta IV Medium and Delta IV Heavy rockets share the same Delta Cryogenic Second Stage (DCSS).The rocket is presently being phased out in favor of the Vulcan rocket from United Launch Alliance, which has more affordable cost for the same capacity.The largest member of the Delta IV family and a former expendable heavy-lift launch vehicle is the Delta IV Heavy.