SpaceX cleared to launch Super Heavy-Starship rocket on third test flight today

SpaceX's huge Super Heavy-Starship rocket, by far the most powerful ever built, was primed for launch on its third test flight Thursday, an attempt to boost the unpiloted upper stage into space for a sub-orbital hop to a controlled re-entry and splashdown in the Indian Ocean.

Liftoff from SpaceX's Boca Chica, Texas, flight test facility on the Gulf Coast was planned for 8 a.m. EDT, kicking off an eight-and-a-half-minute climb to space.

The flight follows formal clearance from the Federal Aviation Administration, issued late Wednesday, that concluded "SpaceX met all safety, environmental, policy and financial responsibility requirements."