FAA to ground the SpaceX Starship Super Heavy launch program pending a "mishap investigation."

[VMA131Marine]

5. On the one hand ...

having 33 engines means you can afford to have two or three shut down during the launch because each one only represents 3% of the total thrust of the rocket. The Saturn V first and second stages both had five engines so losing one meant losing 20% of the total thrust. That said, the Saturn V Rocketdyne F-1 first stage engines never had an inflight shutdown. The Soviet N1 moon rocket, in contrast, had 30 engines in its first stage, almost as many as Starship, and never had a successful launch. Indeed engine failures played a role in all four N1 launch failures. With that many engines, there’s just more likelihood of something going wrong and then a failure can cascade from one engine to the others.

Based on what we know so far, my guess is that the engines that shutdown on Starship were damaged by debris gouged out of the ground under the launch pad. It’s not obvious why this then prevented stage separation and second stage ignition except maybe the conditions for this to happen were never met until after the rocket had started tumbling. At that point there wasn’t enough authority in the thrust vectoring system to bring the rocket back under control.

I’m not sold on using so many engines, but developing a large engine equivalent to the F-1 was probably cost prohibitive and small engines would likely be needed anyway for the boost-back burn, descent, and landing.