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.…