SpaceX conducts a launch rehearsal with its first Starship V3 megarocket at its Starbase site in South Texas on May 11, 2026. (Image credit: SpaceX) SpaceX has fueled up the new variant of its Starship megarocket for the first time ever, preparing for a crucial test flight that could launch as soon as this week. The company assembled a Starship Version 3 (V3) vehicle for the first time over the weekend , stacking a Ship upper stage atop a Super Heavy first-stage booster at its Starbase site in South Texas. That set a new record for the world's tallest rocket at about 408 feet (124.4 meters), besting Starship V2 by 4 feet (1.2 m). Aerial view of the launch rehearsal. (Image credit: SpaceX) "Launch rehearsal complete. During a flight-like countdown, more than 5,000 metric tonnes (11+ million pounds) of propellant were loaded on the fully stacked Starship and Super Heavy V3 vehicles for the first time," SpaceX wrote Monday in a post on X that featured four photos of the rehearsal.…