This is the second flight engine to come off the new RS-25 production line and the second of four engines that will power the Artemis V SLS
https://www.reddit.com/gallery/1osykwf
![Artemis V RS-25 engine at Stennis Space Center for qualification testing [credit: L3Harris]](https://www.byteseu.com/wp-content/uploads/2025/11/9u4nmtvhib0g1-1024x1024.jpg "Artemis V RS-25 engine at Stennis Space Center for qualification testing [credit: L3Harris]")
This is the second flight engine to come off the new RS-25 production line and the second of four engines that will power the Artemis V SLS
https://www.reddit.com/gallery/1osykwf
9 Comments
Are we supposed to be impressed by this $100 million engine?
Production engines go through acceptance testing, not qualification testing
Compare this $100 million engine to the Raptor 3 that out performs it in every metric, and costs $1 million… And is reusable.
Sure, why not
Beautiful engine – back in its day. There’s a limit to how it can be updated in the present day to be cost effective. Of course, the price also depends on how much the company is willing to gouge the government for it. The answer so far is – for every possible dollar, with the collusion of part of the government.
Regardless of cost, age etc it’s still an impressive piece of engineering. I was fortunate enough to witness the test firing of a single shuttle engine at SSC. Waaaay back in the day. That was quite an experience. 🚀
All the tubing and lines everywhere makes it look like a first gen raptor engine haha.
Everyone here talking shit on RS-25 as if it hasn’t historically been the most efficient and advanced engines in the world for 40 years.
“Raptor 3 is better and lighter and cheaper” I would hope so, Raptor 3 is brand goddamn new.
What gets me is how these units are built to handle raw, explosive power. The power is on a mind boggling scale. They can and do take a pounding.
Yet they are handled delicately.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
|Fewer Letters|More Letters|
|——-|———|—|
|[Isp](/r/Space/comments/1osykwf/stub/no3mfpo “Last usage”)|Specific impulse (as explained by [Scott Manley](https://www.youtube.com/watch?v=nnisTeYLLgs) on YouTube)|
| |Internet Service Provider|
|[LH2](/r/Space/comments/1osykwf/stub/no24v5n “Last usage”)|Liquid Hydrogen|
|[LOX](/r/Space/comments/1osykwf/stub/no24v5n “Last usage”)|Liquid Oxygen|
|[RD-180](/r/Space/comments/1osykwf/stub/no3dtmc “Last usage”)|[RD-series Russian-built rocket engine](https://en.wikipedia.org/wiki/RD-180), used in the Atlas V first stage|
|[SLS](/r/Space/comments/1osykwf/stub/no4eepa “Last usage”)|Space Launch System heavy-lift|
|[SSC](/r/Space/comments/1osykwf/stub/no1p7id “Last usage”)|Stennis Space Center, Mississippi|
|[SSME](/r/Space/comments/1osykwf/stub/no4eepa “Last usage”)|[Space Shuttle Main Engine](https://en.wikipedia.org/wiki/Space_Shuttle_main_engine)|
|Jargon|Definition|
|——-|———|—|
|[Raptor](/r/Space/comments/1osykwf/stub/no4eepa “Last usage”)|[Methane-fueled rocket engine](https://en.wikipedia.org/wiki/Raptor_(rocket_engine_family)) under development by SpaceX|
|[cryogenic](/r/Space/comments/1osykwf/stub/no3ois9 “Last usage”)|Very low temperature fluid; materials that would be gaseous at room temperature/pressure|
| |(In re: rocket fuel) Often synonymous with hydrolox|
|hydrolox|Portmanteau: liquid hydrogen fuel, liquid oxygen oxidizer|
Decronym is now also available on Lemmy! Requests for support and new installations should be directed to the Contact address below.
—————-
^([Thread #11854 for this sub, first seen 10th Nov 2025, 06:16])
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