Following an aborted launch attempt last week in which several engines failed to ignite at liftoff, SpaceX’s Starship megarocket is back on the launchpad in Starbase, Texas. A 90-minute launch window opens at 6:45 p.

SpaceX will again attempt a major test of its massive Starship rocket on Thursday after abandoning takeoff last week, exposing investors to the risks of the company’s rocky development cycle and heightening the stakes for the critical milestone.

SpaceX shares were down 0.3% in after-hours trading shortly after the launch. This is breaking news. Check back for updates. Read a preview of the launch below. Forget Starship test flight number 13.

SpaceX is launching its 13th flight test of the Starship rocket and its Super Heavy booster on Thursday evening, marking the next step for Elon Musk’s efforts to take astronauts back to the Moon and land humans on Mars.