BOCA CHICA, Texas — One day after receiving approval from the Federal Aviation Administration, the second flight test of SpaceX’s Starship on Friday has been postponed to Saturday, according to SpaceX founder and Chief Executive Officer Elon Musk.

He posted Thursday on X that the SpaceX team needs to replace a grid fin actuator, which is used to help guide the rocket back to Earth safely.  

Grid fin actuators control the packaging, deployments and deflections of the grid fins, which is a lattice flight control surface on the rocket.

This means the launch moved from 8 a.m. ET, Friday, to Saturday, with a 20-minute launch opening at 8 a.m. ET (7 a.m. CT), SpaceX confirmed. The Super Heavy rocket and the Starship spacecraft, when stacked are both known as Starship, will take off from Starbase in Boca Chica Beach, Texas.

Postponements are not uncommon with rocket launches and even the first Starship flight test was pushed back before the second attempt resulted in the rocket’s destruction.

SpaceX stopped the first flight test nine minutes before the 9:20 a.m. ET launch was supposed to take place on Monday, April 17.

At the time, Musk stated that a pressurant valve seemed to have frozen during the cryogenic propellant loading of the nearly 400-foot-tall Super Heavy rocket and stacked Starship.

During the second flight attempt on April 20, the Starship blew up due to a series of problems. It took SpaceX nearly seven months to address the FAA checklist before being given approval on Tuesday by the agency to go for another launch.

Learn more about the history of the Starship's failed first flight test and what went wrong.