Relativity Space on Instagram: "In thrust we trust! August marked the completion of thrust structure build and the start of thrust structure testing on our newly activated structural test stand, alongside other exciting program milestones, including: - First stage tank welding underway, with initial circumferential friction stir weld joining 2 fuel barrels - First flight Aeon R engine shipped to NASA Stennis for acceptance testing - Hot fire testing of the Aeon V second stage development engine