Why did the Falcon 9 go from a 3x3 configuration to a ring of 8 around a central engine? Was there some sort of aerodynamical advantage to be found or something?


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  • $\begingroup$ I thought I remembered reading about some improvement for single and double engine-out events, remaining thrust would be closer to the center, but I can't find anything about that nor argue it geometrically. $\endgroup$
    – uhoh
    Commented Jun 16, 2023 at 0:19

1 Answer 1


the main reason is simplicity. in a grid, you have 4 way symmetry. with the ring, you have 8 way symmetry. this makes it so all your engine mounting parts are the same, while before your corners and edges needed different parts.

  • 4
    $\begingroup$ Do you have any evidence stating that is why SpaceX made the change? $\endgroup$ Commented Jun 14, 2023 at 11:35
  • 2
    $\begingroup$ blogs.nasa.gov/spacex/2014/04/18/meet-the-octaweb says reduces weight and streamlines manufacturing $\endgroup$ Commented Jun 14, 2023 at 16:09
  • 9
    $\begingroup$ Consider editing that in to your answer. $\endgroup$ Commented Jun 14, 2023 at 16:12

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