The SLS core to be used for the Artemis 1 flight will use four RS-25 engines. These reusable engines were used on the Space Shuttle Orbiter previously.

Is there a listing of which SSMEs are planned for each Artemis flight, and which STS missions they had previously flown? We are specifically interested in this first Artemis flight.

Four SSMEs on bottom or SLS rocket.


1 Answer 1


Building on the information found in my answer to this question (which answers part of the question above "Is there a listing of which SSMEs are planned for each Artemis flight" and gives this image)

Where are the lost RS-25D Block 2 engines?

enter image description here

the history of the 4 engines on the first SLS booster is

Engine / Shuttle Missions

  • 2060: 127, 131, 135
  • 2058: 116, 120, 124, 119, 129, 133
  • 2045: 89, 95, 92, 102, 105, 110, 113, 121, 118, 127, 131, 135
  • 20561: 78, 81, 85, 90, 88, 104, 109, 114, 121

1 First 5 missions flown as engine 2041

Source: Space Shuttle Almanac (paywalled)

  • $\begingroup$ Do they want to get rid of all the engines since the stage is not reusable and everything will burn in the atmosphere? Isnt it a waste of money? $\endgroup$
    – Kozuch
    Commented Jan 18, 2021 at 13:52
  • 2
    $\begingroup$ @Kozuch pretty much everything about the SLS is a waste of money. $\endgroup$ Commented Jan 18, 2021 at 14:57
  • $\begingroup$ @Kozuch Depends on how you define waste. The engines would otherwise be museum pieces, in fact I've got a beautiful photo of my daughters with an RS-25 in a museum. And the money that was spent refurbishing the engines, especially the avionics (yes, these engines have their own avionics) went to congressional districts that were promised a slice of the pie in the 1960's in exchange for supporting the Apollo program. $\endgroup$
    – dotancohen
    Commented Jan 18, 2021 at 15:25
  • $\begingroup$ @OrganicMarble Do you mean only SLS is waste or the whole Artemis mission? Should they have gone with commercial contracts instead of SLS - would that be doable? $\endgroup$
    – Kozuch
    Commented Jan 18, 2021 at 15:28
  • 1
    $\begingroup$ @OrganicMarble I was referring to the allocation of resources, and the amount of resources allocated. Of course the timelines have changed. SLS has been late on every target, with only a single notable exception. $\endgroup$
    – dotancohen
    Commented Jan 18, 2021 at 15:54

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