🥶 #VulcanRocket's liquid oxygen ground- and airborne-chilldown is complete, allowing the launch team to proceed with filling the booster stage. This is the third of four steps in fueling the rocket for its #Cert1 mission. https://t.co/xFQoT0042V pic.twitter.com/huA4WFSuTT

— ULA (@ulalaunch) January 8, 2024