SpaceX Super Heavy has two types of Raptor, one of them being Raptor Boost, which has no gimbals and limited throttling but increased thrust.

But I can't find information on Wikipedia on how many there are and where they are. I wanted to know this to understand the consequences of the engine failures on 20/4/23 launch on thrust vectoring capacity of the booster.

  • $\begingroup$ Where did you encounter the term "Raptor Boost"? $\endgroup$ Commented Apr 27, 2023 at 18:57
  • $\begingroup$ @RussellBorogove en.wikipedia.org/wiki/SpaceX_Starship $\endgroup$ Commented Apr 28, 2023 at 1:08
  • $\begingroup$ that article should probably have a warning about it discussing a design that's still being iterated on. $\endgroup$
    – Erin Anne
    Commented Apr 28, 2023 at 1:44

1 Answer 1


My initial search was insufficient and I think I've found a much-more direct answer to the question in this Apr 23 2023 tweet by Rhin0 / @SpaceRhino0 which states

- R25,R28,R29,R34,R41,R44,R46,R47,R51,R53,R61,R63,R68,R70,R82,R84,R85,R97,R100 (RB's) and R26,R72,R75,R79,R83,R88,R95,R99,R102,R104,R105 (RC's) Destroyed on B7

- R55,R78 (RC's) and R115 (RVAC) Destroyed on S24

- R143, R145 and R183 spotted on B9

For B7, 19 RBs and 11 RCs are listed, so that's not quite all the engines accounted for, but I think it holds that the RBs constitute the outer ring on B7, as you'd expect from the layout of gimbaling and non-gimbaling engines given by e.g. the Everyday Astronaut page on Starship/SuperHeavy's orbital test.

I've yet to find SpaceX sources using the terms "Raptor Boost" and "Raptor Center" but, taken with the appropriate grains of salt, the community/communities watching Starbase are providing good open-source intelligence (OSINT) and I'm willing to treat them as reliable. I think I'll have an answer to your other question about the differences (as far as the community knows / is classifying them) soon from the NASASpaceflight.com forums.

  • $\begingroup$ Feel like I should note a timeline issue I don't understand here: the Artzius tweet with the LabPadre photo, which would seem to contain SN73 (i.e. numbers in line with the engines ID'd on B7 in 2022), is from before the BocaChicaGal tweet showing RB-33. $\endgroup$
    – Erin Anne
    Commented Apr 27, 2023 at 19:30
  • $\begingroup$ I read recently that not only are RBs still distinguished from RC, but they are planning to make the "middle ten" RBs to and have only the center 3 gimbal once they get more confident in the gimbaling ability $\endgroup$ Commented Apr 27, 2023 at 19:48
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    $\begingroup$ @Speedphoenix that article doesn't make the RB/RC distinction at all, and on a skim I don't see any mention of a distinction between the gimbaling and non-gimbaling engines other than that they're gimbaled. $\endgroup$
    – Erin Anne
    Commented Apr 27, 2023 at 20:06
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    $\begingroup$ I have a vague memory that one of the differences between Raptor 1/1.5 and Raptor 2 is that the gimbal hardware moved from the engine to the attachment point, which would indeed mean there is no difference between a gimbaling and non-gimbaling engine. The idea of making the booster engines non-throttlable in order to squeeze out even more thrust is something that was thrown around, but there is no indication that SpaceX has acted on it. Which makes sense: they obviously still haven't figured out how to make the base type work, and there is no point in optimizing something that doesn't work. $\endgroup$ Commented Apr 27, 2023 at 21:24
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    $\begingroup$ @JörgWMittag Wow, considering the demonstrated performance of the Raptor so far, it's really gonna be something to see when they figure out how to make it work. $\endgroup$ Commented Apr 28, 2023 at 1:13

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