Limited edition T-Shirt available now, support the channel and get this remix of the NRO's infamous spy satellite patch: www.bonfire.com/hullo-39/

"I never thought I'd die firing side by side with a fourth RS-25 engine" "What about dying side by side with a friend?" "Aye, I could do that"

Cue Indiana Jones: “that engine belongs in a museum!”

During my 15 years at Marshall, I witnessed a lot of test stand firings of the SSMEs abd was amazed that few employees turned up to watch. It was typically a small group and the occasional museum bus tour. Of course launches were impressive as well. When Peter Diamandis, Byron Lichtenberg and I founded Zero-G and began the x-prize one of the drivers was a simple, economics one: if govt contractors are building as many expensive rockets as they can, what incentive was there to build more affordable engines? I’ve never commented on a video, but the reality of the first reusable engines being tossed off on expendable missions is a poetic tragedy. Thanks for covering this and I hope that some technology spins off that will have them die for a better cause. Absolutely fantastic video! I wish some of my German rocket engineer mentors were alive to see this! We used to debate about the future and I’m so happy that commercial space is slowly but surely surging ahead. Thanks Scott for your channel!

NASA: Reusing old hardware that was stored in warehouse for years Jebediah Kerman's Junkyard: First time?

Those RS-25s deserve to fire up again, just not for the last time.

I have had the rare privilege of working on these Artemis 1 Engines briefly and extensive retrofit tasks on on the Artemis 2 Engines currently. It is sad all the manhours and effort is being thrown into the ocean but still a great privilege and insight into some incredible technology. These engines are built like tanks. Most of the bolts used currently are still in the 80s original packaging by Rockwell.

I've seen many RS-25 startups, but never seen (until super slow motion) how much the engine bell flexes (4:00). Amazing...

These engines should be put into the museums that lost the bid for the shuttles.

The engines are the prettiest part of that franken-rocket.

I had the privilege of working under Dr. Dara Childs who solved the instability problems of the space shuttle main engines. I told him about how they are using his engines again for the SLS which he really liked to hear.

It was amazing to see the flexing of the nozzle on these RS engines during ignition 3:59.

It's better to burn out than rust away - RS25 2019

Government: We have the reusable engines, let's throw them away!

and they gonna use this fantastic engines 1 time and throw them away? what a shame...

Thank you. I certified the SSME testers of the main engine controllers used on the Shuttle program. I had the opportunity to provide a proof of concept to reuse the shuttles SSMEC testers to test the SLS RS-25 controller power supplies. Alas, they opted for manual testing to avoid the cost of software certification. However, I am proud to have been a part of the human space flight expedition and reuse of the RS-25 engine. I am looking forward to the Artemus 1 flight.

after reentry when will the core's landing burn begi... nevermind.

4:00 Whoa! Look at that center engine bell resonate with the combustion instability.

Anybody fancy a fishing trip to recover an engine from the sea?

I know that re-usability is looking to be where it's at in rocketry. And I also know all the cool kids say that's the only thing one can be excited about. But I'm personally excited about SLS. I'm glad it's not the only game in town, but I'm glad it's among them.

Interesting and kind of sad for me. Back in 1997-2007 I machined two parts of these engines on a intermittent cycle. I understood them to be a mixing or preheating ring manifold and a cone shaped part that welded up below the mixer. It was funny to see the NASA engineers when they came in to visit one time because they had not realized we were machining these on a antique 1898 vertical 60" lathe that once was overhead belt driven. So yes a lathe that was built before the Wright brother's even flew were indeed machining space shuttle main engines. I thought it was quit ironic myself. But yes sad to know what you enjoyed making will be discarded as junk into the ocean and I had never really seen them all put together. Thanks for your videos as they are very interesting normally and this one helped put the different engine series in place for me.

Here's how the conversation went down: NASA Tech Guy: Hey, we have four of these RS-25 engines just sitting around gathering dust, what should we do with them? Other NASA guy: Put them in a muse- Boeing Guy: Put them on a rocket! NASA Tech Guy: Awesome

I really hope that somehow at least 1 of the engines gets saved for memoriam purposes. It would be a damn shame to lose them all like that-

I know it's en vogue to mock the STS - but even as a huge SpaceX fan, I gotta say the STS (Space Shuttle) was such a source of national pride for decades, generations even. Especially here in Florida it was an incredible system. All of that being said, as someone who's seen Falcon Heavy launch in person... NOTHING compares to the feeling of watching an STS launch. Maybe the Saturn V did, but that was before my time and was all liquid-fueled. The solids + the RS-25's were just monumental... 12 miles away you could feel every cell of your spleen when that thing launched. For night launches you'd see it light up the Earth like the Sun was at noon... A lot of people will never see the majesty of the Space Shuttle launches and it makes me really sad. I'm only made to feel better by the excitement of the BFR / Starship progress. Even with 31 (plus?) Raptors, I don't think anyone living today will feel the power of solid rocket motors unless - God forbid - we fire ICBMs.

We’re getting the band back together! It’s Space Cowboys with spare parts!

Great reporting! We need to start a campaign to save at least one of the block 2 rs25's. "It belongs in a museum!" We nearly lost th F1's due to poor conservation efforts... and a tremendous amount of care was put into maintaining the capability of rebooting the production line... Losing the rs25 would be another tragedy and failure to learn from past mistakes!

Scott, are you telling me, after a trillion dollars, they managed to cut the engines from the orbiter and welded them onto the external tank? Kudos to them for adding an extra one!!!!

Just put one in a museum please!! Space shuttle is possibly the most iconic spacecraft ever, it's such a shame to throw away all of the engines.

USA: So we decided to resurrect some ancient rocket technology... Russia: First time?

And now I'm rooting for the SLS to never fly, or at worst fly once only. Throwing away these magnificent engines is a disgrace, it's a $2bn rocket anyway, I think they could afford some new engines and preserve history.

Bleeding edge 1980s technology!

Am I the only one that's really happy that we are talking about space travel without talking about the flat earth? And ... now I've ruined it. I love that we are going back to the Moon. This is awesome. I really do hope that commercial space travel will allow for space tourism soon. You're awesome.

At least there’s a real functioning RS-25 engine on display at Kennedy space center

Hey I liked that quick simple intro with the shuttle!! I'm kinda liking the new variety of intros you've been surprising us with!

I remember when the shuttle was being developed. These engines were a marvel of technology, so small, so powerful. Its too bad these engines never made it to museums where they can be seen and remembered, but instead they will die for the sake of an over budget, obsolete, to be short lived SLS.

Once again Scott great video I enjoy everyone you make keep up the good work Mr. Manley

So much re-use of old material, and still it'll cost 2B each ?!! ?

"Kind of" sad? Very sad.

My dad was in Crew Systems until his retirement from NASA in 1975. He was a natural Engineer. Fascinating that I saw events such as Apollo 13 close up. He went back to work on Wensday and came home Friday. They radioed up to the Crew of Apollo 13 telling them how to make an CO2 scrubber of O2 adapter only having 1 hour of breathable air left.

Man, its sooo beautiful to see this engines ignite at 3:41. It gives me goose bumps, i never realised it like this. So beautiful.

This only adds to the mind-boggling differences in speed and cost-effectiveness between Nasa and SpaceX.

Huh, I had no idea about the RS-25 generations thing. They get called just the RS-25 so often I thought they were all more or less the same and didnt know about the planned E and F generations

Good to see you have an SR-71 in your collection behind you! Yes I've seen your videos on it! Great job Manley!!!

When I watched shuttle launches as a kid...I had no idea how much power the shuttle engines had. I always thought the SRBs were the powerhouse that got it to space. Now, after watching your videos, and (forgive the namedrop) Tim Dodd's engine videos....Holy crap on a cracker....the RS-25 is a monster!!! And now I know that's why they (the SRBs) are "just" boosters! Totally amazing!

I don’t know, I’m torn. I guess it’s good that these engines are going to be flown again at all, but just like everyone else has said, really is such a waste to use engines like this on expendable rockets. The SSMEs do deserve better.

10 years in dev, scavenged parts. Is this s dystopian future rocket

These are incredible engines!!! The RS-25 has been tested and refined in the A-1 and A-2 test complex at the Stennis Space Center for over 30 years! They are so well designed & built by the incredible technicians and engineers at SSC that they will start and run every time! They are the most reliable rocket engine ever developed. Even with three ruptured cooling tubes (STS-93, KZfaq search Scott Manley's "How a Gold Bullet Almost Destroyed a Space Shuttle"), these engines still made it to orbit. You could put these engines in their cases, store them in the warehouse, bring them out in 30 more years, change out O-rings and a few gaskets, and they would run again, and again, and again! Watching a RS-25 run on the A-2 stand NEVER gets old!!! Just ask the guys and gals at Aerojet that build them!

Thanks Scott

I agree this should be museum pieces since they are storic

Sounds like a job for the people that found the Saturn first stages at the bottom of the ocean.

It will be so awesome to see SLS finally complete the full test launch and see that core stage return and land safe and sound to be reused again..... oh, wait

These are the most advanced engines ever made, they are iconic and MADE to be reusable. They are now being thrown into the Atlantic ocean.

It's a good thing the SLS uses so much shuttle technology making it cheap to make....oh wait

It would be neat to know which of the engines has travelled the furthest across all missions.

These unsung heros will join the other craft and the people we've lost among the stars in our continuing effort to push the boundaries of science and exploration.

It's going to be FLIPPIN AMAZING.

"We will do it together, one more time!"

9:35, might want to check the landing gear on simulated XS-1 after that late flare. 😁

even on the space shuttle, the reusable engines required rebuilding each time

I think it's much cooler for the engines to keep flying than sitting in a museum.

Dad joke: What do Scott Manley and Rockets have in Common? Both go baldly where no one went before!

Reasons why the SLS has become redundant: - The market has evolved and the need for an ultra heavy lift rocket will be met by multiple companies within 5-15 years - A truly universal exploration vehicle requires in-space re-usability and refuelling. Neither the SLS nor it's modules is built to include such capabilities due to it's heavy use of recycled parts - In order to ensure a tightly packed and reliable launch schedule, again only useful if you re-use your spaceships, you need redundancy. Expendable rockets can offer this, but only with a big cost overhead - If you wanted to ignore all these issues there were better ultra heavy lift designs on paper back when the SLS and it's parts were put into production or even prior. As an example look at Sea Dragon Reasons to keep the SLS around: - Job security I guess What NASA should do to replace the SLS now: Buy rockets from SpaceX and ditch the Starship, if you want to, in favour of whatever you want to put on top instead. Alternatively do the same thing but with two contractors to keep the politicians happy and/or pretend like anything really competitive is in production.

I liked this video alot. It answered a number of questions I had about the RS-25's and it's variation history. What I liked about the shuttle is that it was completely reusable except for the main tank. Everything else came back to earth and reconditioned and flown again. I, too, wish the RS-25s could be flown again, but the way I see it for powering the SLS's sake, it is a nice send off to the engines powering our continued future into space. Great informational video about them.

This is interesting . When I was 20 I worked at Pratt and Whitney in WPB FLA. My paperwork said I was a janitor. However I did not do any of the tasks that would be expected. My job was to clean the very large milling machines, and prep them for new paint. This was about 80 or 81 One of the things I saw then were very large nozzles like the ones in the video. kind of cool.

The RS-25 was meant to be reusable rocket engines...now they're gong to throw them away after 1 use...Really?!?!

4:40 Phase 1 and 2, 104% 109%...you got those muddled up in commentary.

God damn. I didn't know Pratt made the shuttle engines. Much prouder of my company now

Ok, I'll grant you genuine nerd points for going through the specific engines.

But let's not lose the big picture: Complete and functional RS-25's sitting in museums forever and no Artemis program, or a successful and historic Artemis program, and no complete and functional RS-25's in museums. I vote for going back to the moon as opposed to mothballing useful hardware, because any 21st century artifacts left on the moon (as opposed to museums) will also include the historic value of the first woman on the moon. It will be another historic US space race win for the world to remember for thousands of years. This is a history in the making, that should trump hardware on display that frankly, few of you will ever visit.

so what you're saying Scott is Boeing took all these years to make a couple of tanks and some avionics? and were throwing away these tanks along w reusable engines at end of each flight? We're going backwards instead of forwards, thank god we have Elon and Jeff. Don't get me wrong I can't wait to see this fly but when you think about all of this coupled w no vehicle to get our astronauts to and from space its kinda sad

Scavenging is good. Scavenging saves money. Magellan was a super-successful program, and most of the spacecraft was spare parts from other programs. I worked on Magellan, and at one point, I realized I was holding a cable which had been made for, erm, Voyager, I think. Humbling.

Hi Scott-- Very good job. Just for the record, I worked for Rocketdyne for almost 20 years in that program, and never heard the 'RS-25' designation once.

Dont they have a RS-25 sitting by itself in the shuttle building at KSC? EDIT: I misunderstood what Scott was saying at the beginning

Yippee. NASA finally pulled the stick from its butt. Its taken longer to build a single SLS than the length of the entire Apollo program. I'm so proud of the of the dead weights running this thing.

Hi Scott, thank you for the lovely images from the Space Shuttle.

Howdy from Arizona Scott, love your channel I am a space nut not nerd because of my lack of knowledge. But I learn from you! Thanks you Scott!

I’m working on a part of the RS-25 restart and the hardware I’m using to develop my software (in preparation for the new hardware) is indeed much older than myself

I'm sure Bezos can go out there and recover a few of them to put in museums.

Excellent video and the best part is you know exactly what you're talkin about, and that's a thumbs-up in my book

Sounds like this reunion's gonna be a blast.

I like how when Scott says "moon" it sounds like he's saying "Mun"

Imagine some Nerd in the future telling stories of every single ~1000+ SpaceX Merlin engines in existence.

HELLO from the 🇬🇧 May the FORCE be with you ALL BEST WISHES .nice 1 scotty

So, since the shuttles in museums have no engines, it's pretty much guaranteed that someone is going to make a movie where a plot point is the main characters breaking into a museum to steal a shuttle to get into space.

Gonna be very sad knowing these will be on the ocean floor minutes after launch never to be seen again

It would be neat to get the core of the SLS to flip around and hit the ocean top down and some one grab these engines from the ocean and put them on display ?

In the sequence from 3:40 you can see how much the engine bells deform when the fuel ignites. Quite impressive. Also the exhaust shape and translucent color with the small white cones inside of them look IMHO very cool

This was a little over my head, yet very well presented !

Is the Green Run basically just a static fire?

A challenge for Elon musk. Rescue 1 of these engines before it sinks(I know it may be in smashed on impact but history's worth a try)

Super cool, my uncle worked on the Shuttle program 🚀

My grandfather was an engineer at an aerospace company way back in the day and designed some part of the fuel system on the RS-25. I never got the full story from him but he was there designing rocket and missile and helicopter parts for many years. Mom said he worked on the ICBM's back during the cold war too. Interesting man to say the least..

These veteran reusable engines being expended and none going to museums is the ultimate punchline to the joke that is SLS.

Didn’t back in the 1980s they proposed a cheaper dumb down version of the RS 25

Really excited to see the SLS explosion on launch pad footage, going to really give the N1 explosion a test!

Great and very informative video. Thanks Scott!!!

So you're telling me, after all these years, the rocket ain't gonna be reusable?

Someone needs to sponsor the smithsonian or Scott or bezos to fish them out of the Atlantic Post launch. These girls dereve a more fitting burial than the depths of the ocean.

I’m going to Florida to see this launch 🚀 I’m excited 😊

I don't share Scott's expectation that none of these RS-25's will end up in a museum. That's based on the idea that we're going to get 4 SLS launches instead of it going the way of Ares I and getting one launch before being cancelled.