Fifty billion between Constellation/SLS/Orion and not launching a single human into space is pretty sickening.

@@farmingganja5277 Constellation is not part of SLS, except from the 5 segment SRBs. Combined SLS+Orion development costs, if you include Orion constellation costs, are almost 40 billion, up to the first all up launch. By contrast, that's less than the Saturn V's development cost (49 billion) or the Space Shuttle's development cost (48 billion). With proper context it's not anywhere near as bad as many people try to potray it. Not great, not awful either. Flat development budgets definetly didn't help.

@@brokensoap1717 How many SLS missions will have to fly before the development cost per mission comes down out of the stratosphere. The Saturns flew what, nine or ten times? They built 4 Shuttles and flew over 132 times. How many SLS missions do you think will fly, dumping something like a billion dollars worth of RS-25's to the bottom of the ocean at every shot? IMHO it's a boondoggle of epic proportions and if it flies even twice, before being replaced by some other commercial option I'll be shocked.

Ferengi Rule of Acquisition #3, "Never spend more for an acquisition than you have to" 🤣

NOPE. The tools to make an F1 don't exist.

I loved it, too, but "dry and chunky" are only terms to be used by people who don't like getting into the weeds. Instead, I'll call it "fascinating."

Thanks, I appreciate that. I try to have the level of detail that I would want and still make it approachable to people who are less of a space enthusiast than I am.

rac-3 aka ksp players lmao

That just sounds crazy... I love it

@@randomstuff-cu4of Very Kerbal

Thanks, I always like more information, especially from those close to the programs... I'm not confident that the Saturn V based version would have flown earlier as it looks like it has more development work than SLS does.

@@EagerSpace I remember he indicated that updated manufacturing techniques, computer updates and the F1B rocket motors would be all it would need. He thought the design was rock solid and could be built in far less time than SLS....He was a pleasure to talk to...not many opportunities to talk to an engineer that worked the Saturn project.

@@EL-sp5zi I'm skeptical. SLS block 1 uses 5-segment SRBs already developed for Ares I/V, RS-25 engines directly from shuttle, a second stage from delta IV. The only big new thing is the core stage. If you ended up with the same set of contractors for the Saturn V version, I think you'd end up with the same slow progress.

Yeah...Boeing can hold a candle to the North American/,Rocketdyne cooperative effort years ago.

I thought that another reason why was that many of the engineering changes were made quickly and either not annotated on the blue prints or were just scribbled on the blue prints and impossible to read.

then the engineers that actually bult the F1 dies, and those papers frequently get burned.

Agree with all of this... IIRC, NASA's original estimate for the two-stage flyback design was about $9 billion, and I think that may have been before the payload increase to make the Air Force happy. Given that they spent $5-6 billion on a less-reusable shuttle, the two-stage flyback probably would have been well over $10 billion, and simply would not have happened. It's interesting to think about what might have happened if shuttle didn't go forward - would NASA be in a better or worse place right now?

@@EagerSpace I have actually wondered this myself many times. Maybe the shuttle concept was too ambitious and the technology wasn't quite there, but they pushed against the grain and made it anyways. Would it have just been better to not do this and continue down a path of Apollo derivatives?

@@elijahhmarshall You might want to go watch my video: "the shuttle: what went wrong?" The real goals behind the shuttle program were to keep the NASA centers open, the Apollo contractors still in business, and the congresspeople in the states that had either of those in office. And the shuttle program succeeded admirably at that. It established NASA as an ongoing concern in the government rather than something created just for Apollo. Apollo derivatives were not going to happen. The point of Apollo was political - to beat the soviets - and once that was done, the majority of people lost interest. Without shuttle, it's possible that NASA would have been chopped way down and there wouldn't have been any human flight after that.

What? The shuttle never flew more than 9 flights in a year (1985). Average was six. There is no indication the infrastructure and workforce could have ever handled 24 flights in a year.

It's unlikely we would try to build an old-style F-1, the proposal would be for an F-1B, likely uprated a bit. The F-1 is decent for a gas-generator kerolox engine; with sea level/vacuum ISP of 263/304. A fair bit away from the 311/338 of the RD-180, but somewhat close to Merlin 1D's 282/311. I don't think building the F-1B would be a particularly challenging undertaking; it would be somewhere between SpaceX's original Merlin development and the development of Raptor and BE-4. And the F-1B design has already been at least thought about.

15 tons of liquid oxygen and kerosine per second

It’s amazing how quickly we lose knowledge. Some people who built those engines will still be alive. Their knowledge and experience should be recorded before it is lost. It’s like Concorde: from the same era and so ahead of it’s time that even today nothing comes close to it. And so much of that knowledge is being lost too.

Propellant*

Absolutely right. Here are the numbers: The Shuttle's promoters originally envisioned costs at $260 per kilogram to low earth orbit, but by 2011, the incremental cost per flight of the Space Shuttle was estimated at $18,000 per kilogram, nearly 70 times that amount, and more than 3x more expensive compared to the non reusable Proton launch vehicle's estimated cost of $5,000 per kilogram. en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle_program Looking at the total program cost of 209 Billion 2010 dollars, compared to the costs of Apollo, we get the following: Shuttle program cost: 209 Billion (2010 dollars) $245 Billion (2019 Dollars) ($ 1.8 Billion per launch!) vs 134 Saturn 1b launches (shuttle cargo only) 45 Billion (2019 Dollars) ($ 336 million per launch) 100 Saturn V Launches (Moon Missions) 123 Billion (2019 Dollars) ($ 1.23 Billion per launch) Total Apollo alternative history cost 168 Billion (2019 Dollars) Net Savings Apollo vs Space Shuttle $ 77 Billion (2019 Dollars) and 14 lives. Hindsight is always 20/20, but at the time NASA knew how much it cost to develop the Saturn, and should have known that it would have cost at least as much, or more, to develop the shuttle, and that the price of the shuttle included scraping the entire $ 26 Billion investment in the Apollo program, in order to "save money". As it turned out, however, the existing Saturn 1b could have launched everything the shuttle launched for about 1/6 of the shuttle's cost, and for even less than the Proton rocket noted above. More than enough left over to go to the moon 100 times, (2x each year for the last 50 years)! and still have plenty of money left over for a space station, moon base, and maybe even mannned fly-by's of Mars and/or Venus - all in the 70's. We might even have made a manned landing on Mars - in the 80's. This is what we gave up to "save money" with the Space Shuttle. Note: this is only the money spent on the shuttle, and does not include the SLS ($20 billion) Orion ($21 billion) and Artemis, (35 billion) etc. This is what it costs to re-invent the wheel.

The Falcon 9 is the first sensible crew-to-LEO rocket the US has had since the Gemini program, the Saturn IB and the Space Shuttle were both complete overkill for that purpose. If Apollo had continued, you’d want a smaller rocket to launch the capsules and maybe a smaller version of the service module as well.

@@ewan.cartwright The Gemini-Titan launch system was incredibly dangerous and limited. The ejection seats installed on the Gemini spacecraft would have likely killed the astronauts if used at any point in the flight, and the rocket itself was an early ICBM repurposed for spaceflight. It certainly would never meet current human spaceflight standards. I like the Falcon 9, but that is 21st Century tech. It is the application of lessons learned over the past century of spaceflight efforts which makes it so valuable.

I thought about that as well; from a size perspective the RD-170 is about the size of the F-1. I think it may have been them being comfortable with both the quality and the availability of the RD-180 because of the history with the Atlas V. And the RD-170 would have been 10% lower in thrust than the F1-A/B and 20% lower then the 2Mlbf version if they built that.

@@EagerSpace According to online sources the RD-170 was actually more powerful than the F1-A, and of course was much more efficient than any version of the F-1 engine.

@@sycodeathman The sources I've look at put the F-1A just over 8 MN at sea level, and the RD-170 either at 7.2 MN or 7.5 MN at sea level.

@@EagerSpace Ah my mistake, I was reading the numbers for the improved F-1 engines used on Apollo 15 and 17. That being said, RD-170 sits in between thrust performance of the F-1 and the F-1A, but does still stand as the most powerful liquid fueled engine ever flown.

Because the chief advantage of the RD 180 was an existing engine-Production that just had to be purchased. Willst the RD 170 last flew in 1988 with production long Schutt down. So if you have to use restated Production from scratch you might as well bid F-1 B ore a new ORC.

Since they are talking about a first stage engine I'm sure it's sea-level thrust.

Thanks for pushing me towards that bit of history... The air force paid to build the E-1 engine a possible replacement for the Titan missile, but it was small, only 1,700 kN. The AF paid for initial development of the F-1 but halted because they didn't have a need for such a large engine, and then NASA paid for it from then on.

As SpaceX has proven with the Merlin engine. Completely reusable first stage. That sums it up. Next comes Raptor, a LOX/LCH4 engine. Where was NASA who completely missed the point about the future of space launches?

@@stuarthirsch Yeh, NASA is no longer the organisation that put men on the moon in less than a decade starting from scratch. Little more than a bloated bureaucracy these days. Even the Shuttle was a design by committee mess that was both dangerous and expensive.

Interesting question. Methalox is a good first stage fuel but it's really not better than kerolox unless you are concerned about reusability, and the Saturn V-like design was inherently not aimed for reuse. I think they likely would have explored it but of course it would not have changed the outcome.

@@EagerSpace the issue with RS-25 engine is its cost around 100 million dollars per piece, both BE-4 and raptor are much cheaper and would be available in large numbers, I understand that NASA currently make another evaluation of SLS but swapping the hidrolox engines with one that work with methane probably isn't a option without a major re-design.

There was a third option that I didn't talk about that looked at commercial launchers, and one of those options used ORSC engine that looked similar to the RD-170/RD-180.

Why? The SSME is the best and most reliable rocket engine ever made. It is also extremely smooth and efficient. Why not use what works?

@@ultrametric9317 Firstly SSME is not the most reliable rocket engine ever made, plenty of engines have flown more with a better track record, like RD-107a and Merlin. And it's hardly the best engine ever made either. That title belongs to the Raptor or the RD-270. Secondly the SSME is a hydrolox engine, it's simply too weak to be used as a booster engine. That's why both the space shuttle and SLS have to use massive inefficiant solid rocket boosters to compensate for that. Engines like the RD-170 uses kerolox and have far better thrust, which you want out of booster engines. The most idle rocket in terms lf performance would be to have boosters using RD-170s while having a core stage using the SSME.

@@VG_164 And the SSME is also notoriously expensive compared to most other engines & motors!

Certainly a fair point and one that NASA listed as one of the disadvantages of RAC-2. For the first/core stage, I'm not convinced a new core stage plus the F-1B would have been more expensive and taken longer given how price and cost of the core stage and RS-25, and the current design engine cost for the core stage is just ridiculous at $400 million per launch. I understand the second stage point, and I think unfortunately there is no great engine option for RAC-2 other than the J-2X. From a cost perspective, the problem with shuttle derived is that the costs ended up fixed at the expensive shuttle prices plus a premium for fewer units. Once again, that's a point NASA made when discussion the shuttle derived option, and they were certainly right on that. The problem with the current design is that it is just barely affordable and leaves precious little money to do anything else.

Thanks for your comment. I can see your point related to DIRECT, which had a goal to get back flying very quickly and use shuttle components with as little modification as possible. I think it's different for SLS; if you accept that the defined goal - 130 tons to LEO - is meaningful, then I don't think it makes sense to spend any time on ICPS as it doesn't get you where you want; the only thing you get is (perhaps) an earlier launch of a vehicle that doesn't do what you want it to do. It's also had other impacts; NASA has already spent $693 million on the launch tower for block 1 which will be abandoned when they move to block 1B.

@@EagerSpace Oh, the launch tower(s).... (Insert Marlon Brando "The Horror" video clip here)

Both the understanding of POGO and the analysis methods that could be applied to it in 2010 are a bit more advanced than the state of the art in the mid 1960s. There are equivalent issues with large solid rocket motors due to thrust oscillation. Ares I had very significant vibration loads from this, and one of the reasons Europa Clipper was moved off SLS was because the vibration environment was much worse than expected. WRT the overall choice, I think it's pretty clear what the JSC panel thought about the technical desirability of the various choices.

@@EagerSpace That is a myth. Each Saturn V was a separate case. They all showed significant pogo, but in some cases it - particularly Apollo 13 - it came near to destroying the rocket. Putting in accumulators was a black art. Yes computational fluid dynamics has come a long way but such problems are endemic to heavy staged rockets. Even the Titan nearly didn't make it to man rating because of pogo. On the other hand, the characteristics of the SSME are by this time completely known.

Dynetics and PWR had an improved F-1 called the F-1B that they pitched for SLS in 2013. I would have been much easier to manufacture. arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/

SLS is exactly what Eisenhower was talking about when he coined the term "military industrial complex", though it's aerospace rather than military.

Ssturn V was designed so quickly because of an ethnic homogen workforce. Look at any video from the design phase and its all white, middleage men. Todays diversity leads to design by focus groups and it does not work. That is the reason why all innovations are from small startup firms with homogen workgroups since all large western companies play the diversity game.

@@EagerSpace well then it's not the same really. Certainly not "exactly". Further to this the problem that you have highlighted in your video was one in which NASA are just following direct orders from congress. No flexibility in the instruction manual.

I know I'm late to the party but I agree. Nixon and congress gave NASA 2 options and they picked the wrong one.

@@12pentaborane I was told much the same thing by a NASA engineer.

Two references: www.cbo.gov/sites/default/files/109th-congress-2005-2006/reports/10-09-spacelaunch.pdf and books.google.com/books?id=Zn4gAQAAIAAJ&q=%22Apollo+Saturn+V+launch+vehicle+had%22&dq=%22Apollo+Saturn+V+launch+vehicle+had%22&hl=en&sa=X&ved=0CB8Q6AEwAGoVChMI44uQwcHyxgIVDxaSCh1rLQk_#v=snippet&q=%22Apollo%20Saturn%20V%20launch%20vehicle%20had%22&f=false

140 tons refers to the injected mass of the SIVB and the Apollo stack in LEO on an Apollo mission including the dry mass of the upper stage which isn't useful payload or propellant mass In reality the payload capacity was ~125 tons

Part of it is simply that SpaceX is vertically integrated; it's in their best interest to build as Raptors as cheaply as possible because that makes Starship cheaper and makes them more money. AR is in the business of making engines, and it's in their best interest to sell engines for as much as possible, and they have a fully captive customer; there is no other hydrolox engine out there that works for SLS. And part is certainly the number of engines planned; AR is only building 18 of them, where SpaceX will use more than that on a single SuperHeavy booster. And part is the design; the RS-25 is just ridiculously complex. This is pretty much by design for SLS; it was clear at the beginning that the RS-25 would be the only engine choice and NASA would just have to suck it up and pay for it.

Elon's estimates, aside of usuall brag and lack of idependently verified bookeeping, might largely depend on economy of scale ( building large number of engines continously ). On the other hand, RS-25 isn't really worse than raptor and is already PROVEN. Total 46 has been EVER built ( divide cost of industrial base and R&D among them), which is about 150% what is going to be required for for _single_ Starship/Superheavy.

​@@piotrd.4850 There's no 'might' about it. Economy of scale is very much how SpaceX have achieved low cost for Merlin, and intend to for Raptor. Even so, there's no denying that RS-25 is uniquely expensive. The RD-180 is similarly complex, double the thrust, human rated, and still a tenth the price. And not particularly mass produced, apparently about 6 per year, which is what NASA would need for 1-2 SLS launches per year.

I've seen estimates that $250 million per RS25 is more realistic.

Well, we accomplished atleast 2 of those things! Diameter and and Orion is reusable

8.4 meter core with 4 instead of 2 F-1s sounds like Jarvis on steroids, would be an interesting sight to see, though not sure if you could even fit the plumbing.

@@_mikolaj_ F-1B based design is nice!

LOL. What Starship?

I haven’t yet viewed the entire video, but the problem started in the 1970’s, specifically the Nixon Administration. NASA had been forced to cancel the last three Lunar Missions, and NASA had several goals in mind for post Apollo, but they were all shut down except for the Shuttle. So, NASA was adrift, as it had no real goal. The last president who had given NASA a goal was Kennedy. Second, the Shuttle system as built was NOT what NASA had in mind, but under Nixon, NASA was forced to build a massive payload bay, in order to accommodate the needs of the military and intel agencies. Ironically, those entities opted not to use the Shuttle, and launched their own satellites. But NASA was stuck with a huge vehicle, and an extremely unsafe vehicle. Also, the appeal of the Shuttle was that by reusing most of it, it would be much cheaper, and be like running an airline. Well, airplane’s don’t have to endure the punishing stresses of getting to and from orbit. The Shuttle turned out to be MUCH more expensive than the expendable Apollo/Saturn, and the launch rate never came close to what NASA expected. I think NASA originally envisaged a much smaller “Shuttle” (without the massive cargo bay) which could have been placed above the booster (probably the Saturn), and used a simpler heat shield than those tiles, and would have the capability to pull the spacecraft from atop the stack in the event of a catastrophic failure with the booster. The savings would come from its ability to land like a plane (water recoveries are expensive). Also, because of its design, it couldn’t go farther than low earth orbit. The orbiter could not survive the high velocity re-entry that Apollo could. The Soviets figured this out very quickly, and abandoned its own version of the Shuttle. It just isn’t reliable enough for a human crew, and we were fortunate that there weren’t more catastrophic failures. And the Shuttle system just couldn’t match the sheer lifting power of the Saturn V. Our first space station was much larger than the various parts of the ISS, and was a converted third stage of the Saturn V. Unfortunately, because of long delays with the Shuttle, we weren’t able to save Skylab, as it’s orbit decayed. The Saturn was not only the most powerful booster, it was extremely reliable, with no catastrophic failures, and could even survive a lightning strike (which occurred with Apollo 12. Had we kept the Saturn, its electronics could easily have been upgraded over time, (same with Apollo - which is the real spacecraft; Saturn was the booster), just as had been done with the Shuttle. The other safety issue is the use of Solid Rocket Boosters, which were chosen for financial reasons. The problem is that unlike a liquid fueled booster, once you ignite the SRB(s), there’s no shutting them down, and the orbiter had no launch escape system. The two systems were really only developed a decade apart, Apollo Saturn in the 1960’s, and the Shuttle in the 1970’s. And quite frankly, Apollo/Saturn was superior to the Shuttle System, in terms of reliability, cost, and safety. Had we stayed with Apollo/Saturn, we would have probably achieved more because of the savings. The fact that we are returning to the capsule configuration is a testament to the success of Apollo/Saturn.

@@johncronin9540, yes, largely agree. You might be overdoing the Shuttle’s 2 losses of mission and crew in 135 total flights, but otherwise yes, largely agree.

I mostly agree. The reason Shuttle was called "Shuttle" is by analogy with an airport shuttle; it's a small vehicle to take people from one place to another efficiently. That's also why NASA always referred to is as "STS" - the shuttle name wasn't really accurate. I disagree that NASA was forced to build the larger shuttle. NASA had a vehicle in mind and simply didn't have enough support to build it because it wasn't broadly useful enough - the smaller shuttle was mostly designed as a way to get to station - as part of NASA's "shuttle and station" program - but there was no station planned, which made their design not very exciting. In shopping around for support, DoD agreed that they might find shuttle useful if it could carry much larger payloads and had much more crossrange, and NASA agreed to make those changes because they really wanted some sort of program. And that was enough to just *barely* fund shuttle. So it was really NASA's choice to go with the big shuttle; they simply had no way of getting the smaller one funded. This ended up backfiring on DoD; we ended up with a rule (not sure where it came from) that government payloads could only fly on shuttle, and that complicated DoD's life tremendously as they had missions that didn't work well with shuttle and they couldn't use their existing launchers. It also pretty much killed the US commercial launch industry. That rule stuck around until Challenger and then DoD spun up the EELV program which has persisted to this day (now NSSL). At some point I'm going to do a video on early shuttle history and why they chose the design they did.

The dimension of exhaust velocity is meters per second, but the normalization to isp using acceleration gives the somewhat nonsensical "seconds" as the units.

There was no way the Saturn V was going to stick around; the NASA budget was just too huge at the time and Vietnam was burning a bunch of money. The real question was whether NASA would exist or it would go back to it's pre apollo state. I'm not a big fan of shuttle as a program, but probably kept NASA around.

At this specific point, NASA had a mandate for a rocket of a specific size. It didn't have a mandated mission though the moon is an obvious one. Sea Dragon as designed does not work because you can't build rocket engines that big; the F-1 for the Saturn V initially had unstable combustion and it took a lot of time and money to make it work. Our simulation tools are far better now, but it's not clear you can build a successful engine twice the size of the F-1, and the sea dragon one is giant. And the single big & cheap engine was part of the allure. NASA doesn't build engines and it's not clear that aerojet rocketdyne knows how to build new ones any more, so they constrained themselves to engines that had already been developed for this exercise. They also wanted to go fast and engine development is generally the slowest part of the process.

It's certainly true that the old approaches are no longer used. But that's because there are better approaches. In 2013, Pratt & Whitney rocketdyne proposed an SLS booster that would use an updated F-1 known as the F-1B. In addition, an updated version of the J-2 known as the J-2X was built and hot-fired during constellation, though it was not finished.

Sea falcon

Yep. The initial SLS study was predicated on the congressional requirements, where were only to get to LEO. The problem being that congress specified a requirement rather than how it was going to be used.

They looked at the RS-68. The radiative nozzle was apparently a non-starter for a cluster of engines next to SRBs, so it would be a new regenerative nozzle and something to fix the "sets itself on fire" feature. It would have a lower ISP though 3 RS-68 engines would produce more thrust than 4 RS-25 engines, and that would have reduced gravity losses a bit. There was an RS-68B planned for Ares V, which had some of the fixes but wasn't human-rated. But 3 engines at around $25 million each would have been a lot cheaper than 4 engines at $146 million each, though the price for the re-used shuttle engines is obviously much lower. My guess is that AR was much more interested in the contract to set up a new production line for RS-25 engines rather than repurpose the existing RS-68 one.

NASA doesn't make choices like this - it's congress who decides what NASA does...

@@EagerSpace Was it not NASA that proposed the STS concept to president Nixon ?

I mostly agree with that. The RS-25 was a pricey engine even in shuttle because of the amount of rework it took after each flight, but it's a really bad choice for an expendable rocket, plus AR is doing their best to maximize their profits because there are no good alternatives and they therefore can just dictate prices to NASA. The proposed F-1B was supposed to be much cheaper to build than the F-1, but I'm a bit skeptical about that with the cost of the "cheaper" RS-25E... I'm not sure you can build a full-flow kerolox engine because I don't think it works with non-gaseous fuels..

I imagine NASA isn’t going to design and build a new rocket for a very long time (if ever again) after SLS

@@robyn051 19 October 2022, and SLS still has not flown. It is intentional that my comment posted three weeks ago does not specify the constructor. Moreover, since the original design is excellent, there is no point making something completely new.

I thought sea level was sufficient for the point that I wanted to make.

@@EagerSpace Well the RS 25 has Vacum ISP of 453 s And the the RD180 around 341

@@EagerSpace And there was Plan for using the AR1 ( like the RD180 but Build in the USA )

@@tobias1396 My recollection is that the RAC-3 team only looked at simple variants based on commercial launchers, and that a re-engine would be beyond that. If they had gotten to serious consideration the foreign source for the RD-180 might be an issues, and that point the AR1 might have shown up.

Congress did dictate how SLS would be built, and NASA listened to them because they are required to by law - congress decides what programs NASA pursues and how much money they have to spend on it. If you want the details, there's a fairly boring video on it here: kzfaq.info/get/bejne/d5qbhtqr1NK7las.html But the choice was just congress - for the constellation program that preceded SLS, the NASA administrator decided that it would be shuttle-based and congress agreed.

The problem with Apollo was that it was unsustainable with the budgets that NASA was going to get. Which means that NASA was in an existential crisis; it wasn't clear that Congress wasn't going to just cut them back to the funding they got when they were NACA. Shuttle did admirably well at doing what NASA management wanted; they wanted to keep the centers from Apollo open and they wanted to have long successful careers. It also did what industry wanted, and what congresspeople with NASA/contractor jobs in their districts wanted. Brilliant, really; they kept doing a single thing for 30 years. Of course, as you point out, the initial estimates were totally unrealistic, but nobody really cared. Nor did they really care when NASA killed the first 7 astronauts. If you want my longer opinion on shuttle, you can find it here: kzfaq.info/get/bejne/q5OhiNWHm7XIoqs.html

Block requires the EUS upper stage - which NASA through would take a long time to build - and more advanced boosters (in original plans, that would be liquid-fueled boosters and in current plans it's the "BOLE" booster, which has a composite casing instead of the current steel casing). Congress said they wanted to see block 1 flying by 2016 and then later agreed with NASA that 2017 was a good target, and that's what led to the phased approach.

As part of the Advanced Booster Competition for SLS held in 2013, Dynetics/Pratt Whitney Rocketdyne proposed a booster powered by an updated version of the F-1 known as the F-1B. So they clearly thought it was possible. Article here: arstechnica.com/science/2013/04/new-f-1b-rocket-engine-upgrades-apollo-era-deisgn-with-1-8m-lbs-of-thrust/2/

@@EagerSpace Proposed, and never built. because it woukd take lots of trial and error to do now with modern manufscturing, what they did then with an oxy torch. Economy of effort.

@@randomotaku4037 Your argument is extremely poor and you clearly did not do your research into the F-1b

@@BeKindToBirds 1. That is not the F1. That is a different engine, the F1b. which 2. is exactly what I implied would be needed, a redesign of the original engine to work with modern manufactiring, engineering and 3d printing. 3. Has anyone actually built an F1B or is it still sitting on paper while Neon Tusk saves our species?

@@randomotaku4037 You are being obsessively obtuse.

The NK-33 / AJ-26 was briefly used in Antares but abandoned because of quality issues. It's certainly true that Atlas V flies the RD-180, but AFAIK there's no close relationship between the RD-180 and the NK-33. There was already an updated F-1 planned for SLS - the F-1B - that would have been much easier and - perhaps - easier to build. That's the engine this proposal was based on.

@@EagerSpace New Glenn, if they ever get its engines certified could be called a child of Saturn, perhaps. But the main thing wasted by Constellation and SLS is not money, but time. Its 60 year old tech to get to the moon, and the US cannot rely on the rest of the world to not take up the torch we dropped forever.

It's certainly true that you can't find RP-1 elsewhere. Technically you could synthesize kerosene if you had water and carbon dioxide - on Mars, for example - but if you are doing that methane is probably a better choice. But I don't think there was any consideration about that during the decision around SLS.

Scaling up would be possible, to maybe 3-4x it's current size. You probably couldn't do much for it's efficiency though, it's already near the practical limits.

Not cynical enough. The appropriation are run mostly by the congresspeople who have NASA centers, NASA contractors, or both in their state. They're helped by all the other congresspeople, as NASA and their contractors are very good at spreading the money across all 50 states: www.planetary.org/space-images/sls-contractor-map Big players in the senate were Richard Shelby of Alabama (Marshall space flight center has a $2 billion yearly budget) and current NASA administrator, Bill Nelson of Florida (Kennedy space center, also about $2 billion a year).

Exactly. I worked in aerospace for most of my career and just when I thought we were looking at big layoffs Congress came through. There is a darker side to it too. Why did Webb take so long with poor management and cost overruns? You know it got cancelled in 2011, but then Congress because of a media push reinstated it and they decided maybe we better build this thing. No one was ever removed from management, they didn't even seem disappointed about getting cut. We used to call it milking the taxpayers.

@@MountainFisher I think Webb is an example of when things get big enough for there to be significant money for old space we see much less efficiency. But at least JWST works and it is doing something that is arguably very groundbreaking scientifically.

The short answer is that SLS was designed to keep shuttle contractors and NASA centers busy rather than be efficient, and if you are building from shuttle components reuse is very difficult.

@@EagerSpace This deserves a dedicated video! You could go into detail on how each shuttle component was inefficient. For instance, I know the tiles were all unique and needed extensive inspections after each flight. But what other options were looked at during their development that might have made them more reliable, interchangeable, and increase turnaround time? Same for the engines.

@@EagerSpace Another video idea: how much maintenance and repair was required on the shuttle “stage zero” infrastructure after each flight? And same question for SLS. It’s apparent that the SLS ground equipment isn’t robust in a few areas. Was the shuttle’s much better? How much of that was/is make work for a jobs program?

Definitely true. The RS-25 uses 4 turbopumps and the high-pressure LH2 one is just a monster in terms of how much power it takes.

Kerolox is dirtier than hydrolox yes, but it's *much* cleaner than the solid rocket boosters that are needed to help launch hydrogen rockets. If you look at the modern SLS for example, more than half of it's fuel is in the SRBs, not the hydrolox tanks. So kerolox actually ends up being cleaner overall. Of course, methane would be even cleaner, but noone was taking it seriously back then.

Is your caps lock key stuck

Thanks.

@@EagerSpace Most welcome. I don't know if it's just me, but whenever I see an unfamiliar acronym, I am distracted from the rest of the presentation until I determine its expansion. (That may be silly as with many acronyms it doesn't really matter what they stand for, but that's just the way I am.)

@@QuasiRandomViewer I agree with you.

Not the exact Saturn v, but an updated vehicle using the same concept.

Because the Saturn V worked. It was just about the least efficient way to get to the moon, but it’s still the only vehicle to ever actually get people to the moon.

@@oberonpanopticon Yes, it worked, but so did Roman chariots. We are in a different time now, better tech, and better rockets.

There are who claim that is the reason, but in fact 40 year old plans are of little use; the materials and techniques aren't widely in use so having the plans isn't terribly useful. But we actually have manufacturers for engines that know how to use the old techniques because they are building engines from that era. And there are designs for updated engines from that era.

Every rocket other than the falcon 9: