We've commented many times that SLS has jokingly been said to refer to the "Shuttles' Leftover Shit" - to point out that many parts of the booster are not just Shuttle designs, but hardware that had actually flown on Shuttle missions - and would have flown again. Prominent examples are the four liquid fueled RS-25 engines on the SLS core, all of which have flown.
A couple of weeks ago, ground teams at NASA's Kennedy Space Center in Florida removed one of the four main engines from the Space Launch System rocket slated to send four astronauts on a voyage around the Moon next year.
The kicker here is they replaced a 10 year old engine with one that last flew 14 years ago and is closer to 17 years old.
NASA officials ordered the removal of one of the massive rocket's RS-25 main engines after discovering a hydraulic leak on the engine's main oxidizer valve actuator, which controls the flow of super-cold liquid oxygen propellant into the engine's main combustion chamber, an agency spokesperson told Ars.
In its place, technicians installed another RS-25 engine from NASA's inventory to the bottom of the rocket's core stage, which is standing vertical on its mobile launch platform inside the cavernous Vehicle Assembly Building at Kennedy.
Because this is only the second SLS launch vehicle to be built and readied for launch, this is the first time NASA has replaced a main engine. The space agency earmarked each RS-25 engine for the first four flights of the Space Launch System rocket a decade ago. This is the first time that list has been changed. Replacing the engine frees the team to work on the engine in parallel to preparing for the launch, and barely affects the amount of time it takes to prepare for this one.
This view shows the Artemis II core stage being worked on in their factory in New Orleans before being shipped to Florida. The bottom right engine is Engine 2063, the one being replaced. Image credit: NASA
The engine removed from the Artemis II rocket—serial number E2063—was built at NASA's Stennis Space Center by Aerojet Rocketdyne, now part of L3Harris, a Florida-based tech company and defense contractor. Technicians finished constructing the engine in 2015. It was the last RS-25 built using leftover parts, such as turbopumps, that flew on the Space Shuttle, but the fully assembled engine has never flown before.
In its place, NASA installed E2061 into the Engine 4 position on the Artemis II core stage. This engine was the final one built for the shuttle. NASA certified the engine for flight in 2008, and it flew twice in 2010 and 2011.
Shuttles' Leftovers? At the end of the Shuttle program, NASA had 14
previously-flown engines and enough leftover parts to build another two. With
four engines per SLS core, the 16 total engines will fly four Artemis
missions. Artemis doesn't recover boosters or other hardware, so they
just get thrown away - dropped into the Atlantic ocean.
This means NASA must purchase more RS-25 engines from L3Harris' Aerojet Rocketdyne at a staggering cost of $100 million per unit, according to a 2023 report from NASA's inspector general. The watchdog projected that each SLS rocket flying with brand-new RS-25 engines will cost $2.5 billion.
This is probably the biggest reason why SLS is most definitely not the future. It can't be. SLS missions are estimated to cost $4.4 billion (without the Exploration Upper Stage to get its biggest payloads; it has never been built); Falcon Heavy launches cost $178 million. SpaceX's Falcon Heavy can only lift about 2/3 of the payload of the SLS so two Falcon Heavy launches at $356 million are required to put as much mass into orbit as one SLS. It's probably still not an easy, cheap way to get rid of the SLS; I bet there's a bunch of little things that need to be modified or fully redesigned if they were to switch to Falcon Heavy, and switching to Starship is less clear to me.
The amount of stupidity and waste associated with SLS is amazing. And costly, very costly.
ReplyDeleteAnd, yes, Falcon Heavy can actually handle all the proposed missions of Artemis. It may require a little LEO rendezvous, but, still, geez, $700 million vs $2.3 billion and most of the first stages of FH are recoverable. I know, let's use SLS!!!
Sunk costs, SiG.
ReplyDeleteTime to give the whole thing the heave-ho and swallow hard and get SpaceX in on the fun in spite of the costs - which will end up being cheaper short- and long-term.
I wonder if we could get the DOGE folks to look into SLS? I guess he's not officially there now, but you know they'll be screaming about it being Elon's company so it's meaningless.
DeleteMaybe this can shed a shred of light here. Was lucky enough to be selected as the welder/fabricator on a bootleg project for the RL-10 Aerojet Rocketdyne hud/lox, engine, designed in 1956. Its pretty much existed unchanged all this time except for very minor tweeks, and a number of option upgrades, like the bootleg, which improved efficiency to the point it was worth 4 billion dollars in satellite time in the 90's dollar sense. It saved that much fuel just by running better with the bootleg, that a geo dat could stay in orbit that much longer. The point I want to make is the RL10, according to the NASA scientist who i worked under who was managing the program, after inquiring if the RL-10 was a suitable candidate for an up-scale version, he talked about how he too was into this and had been trying to get something going in that direction, but to no avail, along with he could not understand why the resistance to such a pragmatic scheme. I mean, u need to see an RL-10 in person, its like a 1966 Chevy C-10, simple, incredibly reliable, crazy light weight even by todays standards, its everything right about a rocket engine, proof in the pudding is its been around all this time, except for the bootleg, which is offered as an option, its pretty much existed in its original form with only minor improvements. Thats a rather serious track record. Going out on a limb here, backing it up with the above record, and having worked as an aerospace welder for many a year, i noticed something during my time, it appears, and you can see this simply by checking b/p dates, fixturing, master part records, with a minor amount of exceptions, you see this dwell period where like no new tech in aerospace was being produced, as if somebody stopped everything for a number of years, of course pre this time period orders continued, another thing happened and this was evident from the crew of expeditors we had, a long slump began, and they too noticed nothing "New" was flowing thru the shop. Not going to name the criminal duo on the seat of power, but you can probably make a guess who. Anyway, this really effected our shop, we where the premier ridged tube assembly house bar none, the place mandrel tube bending was invented. Great shop, truly awesome crew of craft workers, nothing was beyond our capabilities, which got us some rather cool stuff to work on. So that period really sticks out, somebody put a chokehold on the aerospace industry, that i knew from my perspective, it was like this darkness overcame everything, and afterwords it never really went away, to be blunt, something not nice was in overall control. And I think it really had a negative effect for many a year on free roaming free booting R&D and design. Now SpaceX suddenly shows up and they start doing "impossible" things, have "preposterous" ideas and concepts. See what I am getting at here. In simplest terms, when it started to count the most, outside certain aerospace domains, the brakes where applied big time, bit it was rather slick and quietly applied. It's such a different landscape recently. What SpaceX is accomplishing, by rights without certain interference, should have been going in starting the late 80's thru the 90's, and by now there would be certainly at least test bed space industry and off earth occupation of other celestial bodies. U got to be there I think to see it like I tried to portray it. But think about it really, someone put the brakes on big time, they did it very smoothly over a period of years, from the gangbusters time frame of Apollo, and by late 80's it really took effect, quite negatively, it seems something wanted it to be stopped and tightly controlled to the detriment of many things outside that specific domain. Conspiracy theory anyone? Calling Ferris Bueller!
ReplyDeleteSadly, not a conspiracy. It's so much easier to rebrand an existing engine with some different peripherals and doo-dads than to continue to evolve and create. Especially when Uncle Sugar is quite willing to pay 'New' for 'Old and Busted.'
DeleteI, at one time, downloaded a mega-ton of Apollo and post-Apollo/Not The Shuttle plans and design requirements. We were supposed to do what you said about the RL-10. And more. Like the F-1A, a more powerful version of the historic F-1, with about 20% more efficiency, power and cheaper too! Then, of course, there's all the up-variants of Saturn that would have given us a system of rockets (the SLS series is not the first 'core and more' design, by a long shot, of a heavy lift system) that could start at launching a relatively light payload (like an Apollo capsule and service module) up to/well over 500K pounds (think whole space stations like Skylab but better, stronger, faster) in one shot. Plans for reusable side boosters to give the system an extra oomph to put the whole upper stages into LEO for reuse. Reusable capsules. Reusable return vehicles to bring back satellites and and and and.
We had it all. But the Shuttle came and the supposedly reusable shuttle basically got rebuilt after every launch.
And, of course, it's so much easier to pay all the graft and corruption and continue to build the same damn thing over and over again rather than evolve and create and change.
We was robbed. By politicians and bureaucrats who were and are more corrupt and less honest than the Italian mobs.
My favorite story about the Shuttle program is that they were supposed to bring the cost to orbit down to $25/lb. They only missed by a factor of 1000. Yeah, $25,000 per pound.
DeleteI remember reading SpaceX bid to put the TROPICS satellites up with Starship at $36.36/lb, back in 2020. That's here. At the time, I checked the online FedEx rates and it was cheaper than shipping one pound from Florida to Tokyo. Fastest delivery was $115.94.
Think you are both right. Sadly, very much so. We are being ruled by literally a global organized criminal gang which its members have exceeded all historical levels of greed by orders of magnitude. Such that it is difficult to wrap your mind around the expanse of how criminal, they literally infest everything, lastly its membership is in the hundreds of millions counting the lower level minions who do the nasty ground level dirty work, for maintaining their control and revenue streams. After one hundred days, it seems patently obvious all thats happening is a turf war and transfer if control, a newer control clique is organizing and pushing out the previous criminal gang structure.
DeleteA retired Lt Col, Air Force, that I worked with described it as "the Shuttle Mafia", if it wasn't part of the Space Shuttle it didn't get funded. He passed away a few years ago, but he could go on for hours about the projects that got denied in the 90s-2000s.
ReplyDeletePerhaps the “elephant” in the room was(sadly) the RS-68 (LH2/LOX) Yes not as “efficient” in terms of ISP as the RS-25 (SSME) but produced almost 300K LBS more thrust and as of 2022 in production with last units flown in 2023 & 2024. When developed in 1999- 2000 time frame it more or less used the RS-25 as a base then redesigned critical components ( turbo machinery, propellant pumps,etc) to be “ expendable” via less expensive manufacturing technics and as well as an overall more simplified design.
ReplyDeleteMan rated ? No
Could it have been ? Sure.
Less expensive ? Absolutely !
Would a different choice of a first stage main engine make the overall program more efficient and less costly ? ……….I don’t know………………
In college we did a special project with NASA looking at ways to make the space shuttle engines cheaper.
ReplyDeleteThey have always been VERY expensive to make, in my opinion more than they need to be.
Jonathan
Regarding the J2/RS25/SSME, NASA and the manufacturer have known for decades how to produce a cheaper, stronger, more powerful, reliable and reusable version. Doing the exact same damned thing that NASA engineers did to the mighty F1 when they thought about making new F1 engines for use in the early 2000s.
ReplyDeleteSaid engineers 3D scanned every part of F1 engines they could find. Entered all the scans into mighty 3D CAD programs. And reduced the bazillion pieces and welds into about 40 CNC/Additive Printed parts. Cost would have been around $500k per engine. Producing 1.5 million pounds of thrust. Been reusable, restart-in-flight-capable and significantly lighter than the original F1.
We've known how to do this since 3D scanning and CAD and CNC all came online.
But it's so much easier to not progress, especially when the powers-that-be will willingly overpay for expensive stuff.
Anonymous at 8:52 AM:
ReplyDeleteIt was 1) gun control of ICBMs, 2) sealing off the frontier so the serfs can't escape, 3) the usual pork.
With the stories coming out about the insane waste that DOGE is finding, you really don't need anything but #3. NASA and congress want Cost Plus contracts to spread the money around.
Delete