Both AJR and NG provide SRBs for Delta and Atlas. Vulcan will fly NG SRBs. Those will first fly on Atlas. Several of Vulcan’s subsystems and major components will/ are flying on Atlas first: SRBs, PLF, Avionics, Flight Software, Centaur Systems, RL10 engines, etc... https://t.co/PW03KNoGbU

— Tory Bruno (@torybruno) March 4, 2019