In a wide-ranging talk on Saturday night, SpaceX founder Elon Musk reviewed the debut launch of the Starship rocket on April 20. The bottom line, he said, is that the vehicle's flight slightly exceeded his expectations and that damage to the launch site was not all that extensive. He expects Starship to fly again in as few as two or three months.

"Basically the outcome was roughly sort of what I expected and maybe slightly exceeded my expectations," he said. "And I'm glad to report that the pad damage is actually quite small, and it looks like it can be repaired quite quickly. It was actually just good to get this vehicle off the ground because we've made so many improvements in Booster 9 and beyond."

Musk spoke for about an hour during a Twitter spaces event, responding to questions from several journalists and spaceflight enthusiasts. For those unable to listen, what follows is a summary of what Musk said.

On the flight

When the rocket lifted off, there were three engines whose ignition was terminated because the flight software did not deem them "healthy enough" to bring to full thrust. That left 30 of the Super Heavy first stage's 33 engines in good condition, which is the minimum allowable number for liftoff. Musk said he did not believe these three engines were damaged by the gravel and concrete kicked up by the immense thrust created by the rocket as it slowly lifted off from the pad.

"Weirdly, we did not see evidence of the rock tornado actually damaging engines or heat shields in a material way," he said. "It may have been, but we have not yet seen evidence of that."

At 27 seconds into the flight, engine 19 lost communications concurrent with some kind of “energetic event,” Musk said. This also liberated the outer heat shield from four nearby engines. SpaceX engineers are still assessing exactly what this energetic event was.

“So something bad happened at T-plus 27 seconds because the engine 19 lost all communications, and some kind of explosion happened to knock out the heat shields of engines 17, 18, 19, and 20," Musk said. "There were visible fires seen from the aft end of the vehicle for the remainder of the flight, but the rocket kept going. At T-plus 62 seconds, we see additional aft heat shield damage near engine 30; however, the engine continues to run. And then T-plus 85 seconds is where things really hit the fan."

At that point, the rocket started to lose its thrust vector control, or the ability to steer itself. This led to the initiation of the flight termination system.

Flight termination system

Just before a minute and a half into its mission, the rocket's flight termination system was initiated to break up the vehicle before it veered too far off course. Essentially, the ordnance on board the rocket detonates to rupture its fuel tanks, leading to a breakup. However, in this case, there was about a 40-second delay in the initiation of the system and the rocket breaking apart.

This time lag posed no safety issues with the rocket safely offshore, but it is an unacceptable lag for a system that is supposed to terminate flight almost immediately.

Musk said the problem could be solved with a "longer detonation cord" to make sure the propellant tanks are fully unzipped rapidly. However, he acknowledged that working through this issue with the Federal Aviation Administration may take some time.

"The longest lead item is probably requalification of the flight termination system," Musk said. "That's obviously something that we want to make sure of before proceeding with the next flight."