United Launch Alliance’s Vulcan rocket is scheduled to lift off Tuesday, Aug. 12, during a 7:59–8:59 p.m. Eastern window from Space Launch Complex-41 at Cape Canaveral Space Force Station. Launch Weather Officer Jimmy Taeger forecasts a 75 percent probability of acceptable conditions. Designated USSF-106, the flight is Vulcan’s first national-security mission under the U.S. Space Force’s National Security Space Launch program. The payload includes the experimental Navigation Technology Satellite-3 (NTS-3), which will test reprogrammable positioning, navigation and timing signals, alongside an additional classified spacecraft. The expendable VC4S variant of Vulcan will fly with four GEM 63XL solid rocket boosters and a high-performance Centaur V upper stage capable of inserting 11,693 kilograms directly into geosynchronous orbit. Success would mark the vehicle’s third flight overall and clear a path for Vulcan to replace the retiring Atlas V and Delta IV fleets on future Pentagon launches.