The Air Force and the United Launch Alliance estimate it would cost $1 billion to build an alternate to the Russian-built, first-stage engine used to power the Atlas V rocket booster. The Russian-made RD-180 has been closely scrutinized by members of Congress and Defense Department officials due to growing strains in the U.S. relationship with Russia. On March 3, Pentagon Press Secretary Rear Adm. John Kirby announced the Defense Department's suspension of all military-to-military activities with Russia, and the White...