CAPE CANAVERAL, Fla. (AP) — The Federal Aviation Administration says SpaceX must take a series of steps before it can launch its mega rocket again.

The FAA said Friday it has closed its investigation into SpaceX’s failed debut of Starship, the world’s biggest rocket.

The agency says SpaceX needs to take 63 corrective actions and apply for a modified license before it can launch again.

FAA officials say multiple problems led to the April launch explosion and wrecked pad in South Texas. SpaceX founder Elon Musk says he’s improved the rocket and strengthened the pad after the test flight.