Vulcan: Wet Dress Rehearsal planned

United Launch Alliance · August 6, 2026 · blog

United Launch Alliance (ULA) rolled out a Vulcan rocket to Space Launch Complex (SLC)-41 at Cape Canaveral Space Force Station to undergo an extensive test countdown prior to the inaugural flight from our new launch processing lane dedicated to Amazon. Known as a Wet Dress Rehearsal (WDR), ULA is preparing to conduct a full day-of-launch test to demonstrate propellant loading and operations with the new LEO-optimized Centaur V upper stage, designed to enhance Vulcan's performance for Amazon, and the functions of the Vulcan Launch Platform (VLP)-A, the second Vulcan platform to serve Amazon Leo missions on our heavy-lift rocket. The WDR also exercises the first stage hardware and pad systems, the software and procedures for running the countdown and the combined launch team -- all to reduce the risk of a delay on launch day. The rehearsal follows the tightly scripted sequence by rolling the Vulcan from the newly commissioned Amazon Vertical Integration Facility (VIF-A) to SLC-41, performing the entire countdown to fuel the rocket and returning the vehicle to the VIF-A afterwards. The first step -- moving VLP-A and rocket 2.7 miles (4.3 km) from VIF-A to the pad -- is complete. The second step -- an initial test day will be spent going through the "chilldown" process to thermally condition Centaur V and launch platform to handle the cryogenic liquid oxygen and liquid oxygen propellants and partially filling only the upper stage -- was also accomplished. The third step is the full WDR day that rehearses the entire countdown process. Vulcan is expected to spend approximately one week at the pad. — United Launch Alliance

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