I was watching this video summarizing Elon Musk's recent remarks on the orbital test flight, and they mention specific engines. But unless a named engine shuts down and is shown on the small display in the SpaceX feed replay, I don't know where a specific engine is.


1 Answer 1


If you watch SpaceX's live stream of the Integrated Flight Test, you will notice that they helpfully painted the engine numbers onto the inside of the engine bells of all of the engines:

You can see that the engines are numbered in concentric rings, clockwise, always starting in the same corner:

  • The inner circle of three Raptor Center engines is numbered E1–E3.
  • The middle ring of ten Raptor Center engines is numbered E4–E13.
  • The outer ring of twenty Raptor Boost engines is numbered E14–E33.

Unfortunately, it is not possible to see on that shot what the orientation of the camera is. If I had to guess, engines E1, E4, and E14 are directly on the Z-axis of the vehicle, i.e. perfectly leeward (facing the tower) or perfectly windward (opposite the tower).

Engines E17–E20, which had their shielding blown off at T+20s, are in the top left corner of the frame. Engine E6, which lost communication to the vehicle is also in that same corner.

  • 5
    $\begingroup$ I've been using this image stack from this reddit thread, which also starts with the under-Starship camera angle from the test flight. If you compare it to the tower angle SpaceX released you can see which center engine corresponds to the toward-tower side by scrubbing to around 23s to observe which center engine is out. I believe your E1-E4-E14 guess is correct based on that. $\endgroup$
    – Erin Anne
    May 1, 2023 at 18:30
  • $\begingroup$ Don't you think that E1 feels so proud? They can tell their grandchildren "We were 33 engines, and I was chosen to be no. 1." $\endgroup$ May 2, 2023 at 8:54
  • $\begingroup$ Or, at second thought, E1 can tell it to the bottom dwellers in the Gulf of Mexico ;-). $\endgroup$ May 2, 2023 at 9:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.