SpaceX's mishap investigation is officially closed but that doesn't mean it can fly its Starship rocket just yet

• SpaceX is 'ready to launch' its Starship mega-rocket again, pending FAA approval, Elon Musk said on Wednesday. 
• On Friday, the FAA announced it had closed its mishap investigation on Starship's Super Heavy booster.
• The final report cites 63 corrective actions SpaceX needs to address before it can relaunch Starship.

SpaceX's Starship rocket is fully stacked and ready to launch again, its CEO, Elon Musk, said on Wednesday, adding that he was just waiting for the Federal Aviation Administration to approve the company's launch license.

That approval hinges on a mishap investigation the FAA has been reviewing for several weeks regarding the explosion that happened during Starship's previous launch in April.

The FAA announced on Friday the mishap investigation is now closed. However, it doesn't mean Starship has the green light to launch, just yet, the FAA said in a statement.

"The final report cites multiple root causes of the April 20, 2023, mishap and 63 corrective actions SpaceX must take to prevent mishap reoccurrence," the FAA said in the statement.

What happened to Starship on April 20

The Starship spacecraft and its Super Heavy booster were launched together for the first time on April 20. But nearly three minutes after launch, miles above Earth, Starship failed to separate from the booster — a critical step to reaching orbital heights.

Weighed down with its booster, Starship began to tumble back to Earth. Video footage showed the rocket self-destructed mid-flight for safety reasons and never reached space.

It was later determined that Starship had also blasted a crater into its launchpad, spraying dirt, chunks of concrete, and other debris onto neighboring areas.

Some of the debris reached Port Isabel, a town five miles away from SpaceX's launchpad in Boca Chica, Texas, Insider previously reported. 

After the April launch attempt blew up, the FAA required SpaceX to file a mishap investigation report, a common procedure after a flight has gone awry.

But even though the FAA has now closed the mishap investigation, it doesn't mean Starship is ready to fly just yet, the FAA said.

"The FAA will not authorize another Starship launch until SpaceX implements the corrective actions identified during the mishap investigation," the FAA told Insider in an email, adding that SpaceX would also have to comply with all other regulatory requirements for modifying its launch license.

Therefore, when SpaceX is ready to fly its mega-rocket, again, remains to be determined. 

Elon Musk has big plans for SpaceX's Starship mega-rocket

Starship is SpaceX's next flagship rocket, standing taller and more powerful than any previous launch system. The Starship vehicle, stacked atop its Super Heavy booster, stands nearly 400 feet tall.

Musk aims to use this launch system as a workhorse to send humans and cargo to Mars, realizing his dream of building the first settlement there.

The FAA required SpaceX to investigate Starship's mid-flight error

Since the last launch, SpaceX has made more than 1,000 modifications to improve its rocket design ahead of its next test flight, Musk told the journalist Ashlee Vance in a discussion on X, formerly Twitter, Space.com reported.

One of these changes can be seen in the newly released picture of the rocket: a vent and a heat shield have been placed between the rocket and the booster.

Following the rocket's inability to separate from its booster in April, SpaceX has moved to a process called "hot staging," whereby the engines of the Starship rocket are ignited to push the ship away from its Super Heavy booster before the booster's shutdown, Space.com reported.

Musk told Vance, "We're adding an extension to the booster that is almost all vents, essentially," Space.com reported. "So that allows the upper-stage engine plume to go through the sort of vented extension of the booster and not just blow itself up."

The vent and shield aim to protect the booster since SpaceX wants to reuse both the Starship and its booster after each flight. That's the key to the revolutionary potential of Starship: a fully reusable, Mars-grade, human-ready rocket.

Musk told Vance the company also added a water-deluge system to the launchpad, which essentially floods the area with water to keep it from heating up too much, Space.com said.

That system uses a steel plate that's "basically like a gigantic upside-down shower head," Musk said.

Space.com reported SpaceX had also been repairing the launchpad and reinforcing it so that the concrete can withstand Starship's power next time.

This post has been updated to include new information.