ULA Completes Dual Engine Centaur PDR for CCiCap
United Launch Alliance Completes Dual Engine Centaur Preliminary Design Review and Development Testing in Support of Commercial Crew Program, ULA
“United Launch Alliance (ULA) successfully completed the Preliminary Design Review (PDR) and initial round of development testing for the Dual Engine Centaur in support of NASA’s Commercial Crew Program.
Under Independent Research and Development (IRAD) funding, ULA is re-establishing the Dual Engine Centaur (DEC) configuration for performance and human space flight safety. Atlas V is capable of flying both a single and dual engine on the Centaur second stage, but most satellite missions require only a single engine due to the powerful capability of the Atlas V booster to loft the payload into orbit.”
2 Centaurs will be expensive. I have read they might use 4 Centaurs on SLS.
There is a version of Atlas V with 7 solids and a 16′ core. It would lift 70 tons. That ought to lift Orion ok and cost a lot less.