United Launch Alliance Successfully Launches NROL-47 Mission for the National Reconnaissance Office
Article Excerpt: "... A single RL10B-2 liquid hydrogen/liquid oxygen engine powered the second stage. The booster and upper stage engines are both built by Aerojet Rocketdyne. ULA constructed the Delta IV Medium+ (5,2) launch vehicle in Decatur, Ala. This is ULA's first launch in 2018 and the 124th successful launch since the company was formed in December 2006 ..."
Reference: www.prnewswire.com