The second flight of ULA’s Vulcan rocket aims to validate its reliability for launching critical US military satellites. ULA CEO Tory Bruno is confident in the rocket’s success, following a near-flawless debut in January. The Vulcan, replacing Atlas V and Delta IV, is crucial for future military satellite launches. The Space Force requires two successful test flights before committing its satellites. If successful, ULA could launch operational missions by year-end. The Vulcan uses Blue Origin’s BE-4 engines and Northrop Grumman boosters, with minor modifications for improved performance.