Why is NASA Throwing Away Reusable Engines?

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  • Опубликовано: 17 окт 2024
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    The Artemis SLS is the latest and greatest rocket from NASA and more powerful than anything yet flown into space. And yet for all of its modernity for the upcoming moon missions and its competitors like SpaceX and Blue Origin concentrating on reusability, NASA will be throwing away four of possibly the best reusable engines yet made, the RS-25 with each launch just like they did in the 1960s & 70s with the Apollo mission and the one time use F-1 engines. So in this video, we look at how the RS-25 came about and why it's now a disposable item.
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    Written, researched and presented by Paul Shillito
    Images and footage : NASA, Pratt & Whitney, Rocketdyne, Aerojet General
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Комментарии • 1,6 тыс.

  • @tmenzella
    @tmenzella Год назад +646

    Good to see you pushing out content regularly again buddy, hope you’re well on the way to a full recovery. Thanks for your channel. ✊🏻

    • @ShainAndrews
      @ShainAndrews Год назад +4

      Why the emoji?

    • @rolflandale2565
      @rolflandale2565 Год назад +6

      Indeed, the althirthum of YT is horrendous, we haven't heard from Curious Droid, since eternity🙂. Yes there hasn't been much iconic launches since this year. Welcome back🖖.

    • @bastadimasta
      @bastadimasta Год назад +2

      Publishing. Pushing out means something else, something insulting.

    • @dziban303
      @dziban303 Год назад +8

      Techno Varys will *not* be deterred

    • @batman_2004
      @batman_2004 Год назад +2

      Cringe emoji

  • @dion6481
    @dion6481 Год назад +158

    In a documentary I saw about the development of the SLS, is that, the RS-25 were not exactly powerful enough for the job. However, since they were now "disposable", they could be run way over their specifications, because, well, who cares if they are destroyed by the time their fuel is burned. So, from memory, I believe they are used to 115% of their designed thrust, which does give the necessary power needed.

    • @dr4d1s
      @dr4d1s Год назад +4

      I thought that it was 109%

    • @michaelwalker6252
      @michaelwalker6252 Год назад +31

      They were run above their design rating on the shuttles for years. If you listen to one of the shuttle launches you'll hear the throttle up command to 104%, and I think later on it went up to 108%. This increased thrust was due to upgrades made to the engines over the years.

    • @HighlanderNorth1
      @HighlanderNorth1 Год назад +17

      @@dr4d1s
      🤔 Well, it depends. I've managed to boost the power of R25 engines to 116.4%. You see, I bought 11 of them at a govt surplus auction to increase the altitude of my modified Estes model rockets from 800 feet to 800 miles. Unfortunately, I too have been unable to reuse my R25 engines, because the vastly increased altitude they provide has proven to be a double-edged sword. Now I can never seem to locate the rockets after launch. They no longer just float back down into my backyard! 😁

    • @MattH-wg7ou
      @MattH-wg7ou Год назад +1

      What documentary was it? I wanna watch.

    • @donraptor6156
      @donraptor6156 Год назад +2

      If you don't plan on reusing the hardware they can be uprated a Massive amount extra thrust since you can use it all up!

  • @sunspot42
    @sunspot42 Год назад +309

    There’s reusability and then there’s reusability. I think each shuttle launch required about half a billion dollars in refurbishment expenses before the vehicle was ready to fly again, some insane amount like that. A big chunk of it was inspecting and refurbishing those awesome engines. If your launch volumes are sufficient, it isn’t at all clear if this is more efficient than simply using a cheaper disposable engine, one that could be produced for a fraction of the cost.

    • @Jaxck77
      @Jaxck77 Год назад +10

      These do not cost a fraction though.

    • @lordgarion514
      @lordgarion514 Год назад +30

      @@Jaxck77
      I'm convinced that the amount they cost, and the amount of our money Congress is giving their friends for ot, are VASTLY different amounts.

    • @sunspot42
      @sunspot42 Год назад +30

      @@Jaxck77 True, but they were just going to sit around rusting and were already paid for out of the Shuttle budget. So they’re essentially free as far as the new rocket is concerned.
      If you think this program is delayed already, imagine how far behind schedule it would be if they’d tried to make more of the components reusable.

    • @jimurrata6785
      @jimurrata6785 Год назад +41

      Imagine how far ahead NASA would be if they just started from a fresh sheet instead of being shackled to Shelby and his cronies by congressional mandate.
      We're nearly a decade behind and tens of billions over budget with no end in sight if this continues.
      Over $4 billion per launch and $93 billion through 2025

    • @colinjohnson5515
      @colinjohnson5515 Год назад +6

      Wasn’t the amortized of each shuttle mission like $1B? It’s amazing expensive LEO was before SpaceX.
      I wonder how much money NASA could save if they dropped success probability to 99%.

  • @mtnbikeman85
    @mtnbikeman85 Год назад +138

    The flyback booster concept if it had continued would have essentially achieved what starship is trying today but almost 40 years prior.

    • @TheEvilmooseofdoom
      @TheEvilmooseofdoom Год назад +26

      @@MrWolfstar8 Nonsense.

    • @johnmurphy5689
      @johnmurphy5689 Год назад +35

      @@MrWolfstar8 No your wrong, what actually happened instead is that the US Air Force pretty much forced NASA to develop the large Space Shuttle with the expendable External tank because they wanted a LARGE Space Plane that could launch and recover spy satellites over the North Pole, this prevented NASA from using a smaller cheaper Space Shuttle design that would have allowed the budget for a reusable flyback booster to be built.
      If NASA had not suffered from the budget cuts from Congress during the late 1960s and 1970s then they would never have been forced to rely on the USAF to provide funding for the Space Shuttle program.

    • @dr4d1s
      @dr4d1s Год назад +10

      @@MrWolfstar8 If cost is not a concern and large payloads are the measure, we did have the Shuttle Program that flew for 30+ years.

    • @thesteelrodent1796
      @thesteelrodent1796 Год назад +4

      @@MrWolfstar8 if it wasn't for the cost SpaceX wouldn't bother with making reusable boosters. It's not like they do it just as a gimmick

    • @nutsackmania
      @nutsackmania Год назад

      The original comment is correct. I'm sure if you're stupid you'll want to argue that it isn't, but--and I'm just being honest--that impulse is all the proof you need that you're a moron.

  • @uuzd4s
    @uuzd4s Год назад +13

    Good seeing you back into the New Commercial Space Race! I missed those Shirts . . . as well as your well researched space endeavour subject matter! I've worked on the larger P&W turboprop engines for decades and never knew of their Rocket Engine development until just recently. Their reverse flow turboprop's are robust and highly damage tolerant, I would expect the same out of their Rocket Engines. Good Show !

  • @supernanga
    @supernanga Год назад +4

    So good to see new content being pushed out! I hope you're doing well for a full recovery. All the best!

  • @occhamite
    @occhamite Год назад +195

    Actually, new RS-25 doesn't represent "coming full circle, as the F1 was a resueable engine which wasn't reused. Some F1's had accumulated as much as 8,000 seconds total run time, with only minor refurbishments between runs, like replacement of a few minor items like carbon nozzle throats.

    • @battlesheep2552
      @battlesheep2552 Год назад +34

      Damn, that's more than 2 hours. Just imagining an F1 running for that long is unimaginable

    • @marvintpandroid2213
      @marvintpandroid2213 Год назад +14

      You get the gold star for pedant of the day 🌟

    • @jmwoods190
      @jmwoods190 Год назад +13

      And there were proposals for 4 outer F-1 engines to be reused, in the form of the S-1D which would've been a 1.5 stage version of the S-1C(and an upscaled version of the early 5-main engine proposal for the Atlas rocket, which was later reduced to 3 in the final design) in which 4 the outer engines were jettisoned and recovered to be re-used, leaving the center F-1 engine to complete and the rest of of the Single-and-a-Half-Stage-to-Orbit(SHSTO?!) flight!

    • @Ingens_Scherz
      @Ingens_Scherz Год назад +1

      Could they land a first stage? Then no, they were not actually reusable even if they were potentially reusable. How do you feel about that?

    • @lordgarion514
      @lordgarion514 Год назад +25

      @@Ingens_Scherz
      Sorry, but a machine being reusable or not, has nothing to do with whether or not the tech to keep it from crashing exists.
      They are two different things.
      English isn't hard.

  • @SRFriso94
    @SRFriso94 Год назад +95

    This one mystefies me how they can justify it - they even developed a disposable variant of the RS-25 in the RS-68 for the Delta, precisely because the RS-25 was too expensive to be disposable. At least with the SRB's it makes a bit more sense, as the tally after the Shuttle Program ended showed that the recovery and refurbishment of those was pretty much just as expensive as if they had bought new ones every time.

    • @sylvanelite
      @sylvanelite Год назад +20

      AFIK, one of the main problems with the RS-68 is cooling. One of the reasons the RS-68 is cheaper than the SSME is the lack of regen cooling in the nozzle. If you packed them close together on one core, like in the SLS, they won’t be able to dissipate heat effectively. The RS-25 on the other hand has an actively cooled nozzle so they can be packed close together.

    • @derrekvanee4567
      @derrekvanee4567 Год назад +1

      Jusify? Only need to justify how the 1% can get extra tax payer dollers, and be able to throw away the product at the end of its ffirst test, and 12 more after that.

    • @maxkovalchick9529
      @maxkovalchick9529 Год назад +9

      From what I've heard the main issue isn't proximity to each other, but that the RS-68's ablative nozzle being designed for the delta 4 series of rockets with shorter burn times actually doesn't have the durability for the longer burns of SLS, especially if one of the engines were to go out early.
      I still agree though, the RS-25 really is an engineering triumph, it's sad to see them be one and done on the pad.

    • @sunspot42
      @sunspot42 Год назад +7

      @@maxkovalchick9529 better than seeing them just rusting away in storage.

    • @rocketman1104
      @rocketman1104 Год назад +4

      the RS-68 is not a variant of the RS-25, you are thinking of the constellation program, where they were trying to work out issues between using RS-25 and RS-68, they wanted the RS-68 because it provided more thrust, but required a new variant, the RS-68B, which had a regenerative cooled nozzle, it also needed to be man rated, this is incredibly expensive, and is fairly close to redesigning the entire engine since you need new plumbing and control on the engine to use a regeneratively cooled nozzle, versus ablative on the RS-68 and RS-68A. The RS-25 is already crew rated, and regeneratively cooled, so less development would bee required, however they would need more engines per core to provide the amount of thrust they wanted.

  • @MrRioting
    @MrRioting Год назад +18

    Thank you for this very in-depth discussion. I enjoyed all of it. I have been following the space project since childhood and watched Neil Armstrong land on the moon, etc. Been keeping up with the technology and made the trip finally a few years ago to Canaveral. Got lucky in that it was between the Shuttle, which had been retired, and the new Artemis project, relatively unknown at that time amongst the masses, including us. We got to tour the VAB, which had not been possible in the past during the space race, and the shuttle lifetime due to it being used constantly, so that was real treat. Inside, there was a mockup of the Orion. We got to touch it! We learned then that they would be re-using Apollo and shuttle technology including the Apollo Command Module design, the solid boosters and the same engines and fuel tank designs of the shuttle system, and this was the common answer: "Why? Because it works!" We heard that a lot. They were also in the process of refurbishing the crawlers to carry the SLS out to 39 A and B, and of course, we got to tour 39A, which was quite a treat as well. Pictures do NOT do it justice! You have to stand where behemoth rockets blasted off from! I encourage everybody interested in our missions to space to make the trip. Do the tours! Go see the best use of tax dollars ever! The quest for universal knowledge. Put it in your bucket list and just do it! Go on their website and read the schedule of events and try to time it when you can actually tour the launch facilities. Maybe even take in a launch. Space Ex and others are doing it a LOT. Tickets are very affordable as is the whole Cape Canaveral experience. Over there in Orlando is the Fantasy theme parks, but over there at Cape Canaveral is REALITY! They even have a full sized Saturn 5 right there!

  • @throwback19841
    @throwback19841 Год назад +40

    The other thing which the rd-25 stood out for is the very large gimbal range it needed to keep the monstrosity that is the shuttle pointing skywards with flamey end down.

    • @LambdaJack
      @LambdaJack Год назад +1

      Yes! that was quite a fetish!!

    • @SeanCMonahan
      @SeanCMonahan Год назад +1

      ​@@LambdaJack quite a _fetish_, you say? Different strokes for different folks, I guess 😂

    • @loschwahn723
      @loschwahn723 Год назад

      most common problem by such kind of engines ?
      temperatures - even if they can be reused
      ...you should better not

  • @rjm7168
    @rjm7168 Год назад +51

    I worked at Rocketdyne for 12 years in Advanced Programs and am very familiar with the SSME, J2, J2 Aeorospike, and other rocket engines. They are all amazing pieces of machinery. To quote a friend of mine (another Rocketdyne Engineer) the SSME main fuel pump packaged 50,000 HP in the size of an office trash can. Anyway, there really is no such thing as a reusable rocket engine as most would think of. It isn't like parking a car and hopping in the next morning to drive it again. The SSME were removed from the Space Shuttle after every mission, partially disassembled, inspected, refurbished as needed, and reassembled before being used again. I believe the turbopumps were also partially disassembled during this inspection and refurbishment process. I suspect the Space X and other current reusable rocket engine systems are subject to a similar inspection and refurbishment process. So, throwing away reusable engines may not be that much more expensive than reusing them when you look at total cost, including recovery.

    • @raymondzhao9557
      @raymondzhao9557 Год назад +1

      COOOOL

    • @christianrogers5674
      @christianrogers5674 Год назад +5

      Thanks for your perspective! I thought too was that if the engine is simplified and the cost per unit reduced, it may over time be cheaper to throw it away than to land it and refurbish it.

    • @wrightmf
      @wrightmf Год назад +2

      >SSME main fuel pump packaged 50,000 HP in the size of an office trash can.
      for some reason my brain can't fathom a pump of the size of a trash can that has 50K horsepower.

    • @JosephHarner
      @JosephHarner Год назад +3

      That it needed such a high level of inspection and refurbishment seems like a failure of engineering, then. Either the project goals were set wrong to allow for a design that needed so much refurbishment between flights, or the product failed to deliver. I can cut the Space shuttle program some slack for the challenges they encountered that were previously unknown. Far less so the SLS, which responded to the challenges of reusability by throwing in the towel, going for a far less ambitious design, and yet still taking 20 years to deliver the world's most expensive way to put 100t into low earth orbit.

    • @secondsein7749
      @secondsein7749 Год назад +11

      @@JosephHarner it's likely more for precaution's sake than anything else. Even if they managed to reduce the inspection and refurbishment to near zero, protoco/law would mandate high level inspection/refurbishment anyways.
      Like the OP says, space vehicles aren't like any other vehicles. Space vehicles that failed would garner public negative attention and space exploration PR tend to be on thin ice. You don't want your rocket to explode and later have to explain to the public that you put too much confidence in your engineering skills instead of life saving procedures.
      The same principle applies to jet fighters. They require extensive maintenance after each flight. Can the jets skip the maintenance after a flight? Sure but considering the cost of the plane and pilot, the military doesn't want to risk it.
      Better safe than sorry after all.

  • @zandvoort8616
    @zandvoort8616 Год назад +50

    It’s a great shame they didn’t used some kind of tech like what they plan for the Vulcan rocket to allow the engine section to return to Earth via an inflatable heat shield.

    • @pyropulseIXXI
      @pyropulseIXXI Год назад +4

      Why is that a shame? Sounds like overhyped nonsense. Reusability of rockets really doesn't save that much and is super niche

    • @michaelwalker6252
      @michaelwalker6252 Год назад +5

      These engines were designed in the 70s. They have been reused over and over for years. SLS IS WHAT THEY ARE BEING USED FOR INSTEAD OF THROWING AWAY AFTER THE END OF THE SHUTTLE PROGRAM. Recovery systems are expensive so why spend the money to recover them?? This is them going out with a bang instead of being trashed. "Disposable" is not an accurate description.

    • @CommyPlayz
      @CommyPlayz Год назад +5

      @@michaelwalker6252 This is true i mean, if you use the shuttle’s engines for SLS instead of it being placed in the Air & Space Museum it is the retiremnt flight of those engines. It did what it was meant to do for the past 30 years. I think it is fair to put these glorious pieces of the space race to an end (shuttle was from the 70’s post Apollo 17)

    • @zandvoort8616
      @zandvoort8616 Год назад

      Maybe somebody can recover them from the sea and bring these historic engines back to a museum. I thought SLS would be an ideal proving ground for the ULA/inflatable heat shield recovery system.

    • @tma2001
      @tma2001 Год назад

      @@pyropulseIXXI yeah its not like SpaceX have launched more payload to orbit than the rest of the world combined this year ... hmm I wonder how they managed that.

  • @tomtierney792
    @tomtierney792 Год назад +8

    Thank you for this info.
    It seems that everyone is focused on the main engines.
    Of course, these give a great show at lift-off and NASA has to have something dramatic to show the public for all the money spent.
    I think that the Orbital Maneuvering Engine (AJ10-190) is another good engine being thrown away, ah, I mean disposed.
    It certainly isn't as sexy as the SSME but it was the one shuttle engine that met all the original specs.
    I find it difficult to find much info on this engine and would like you to do a video on it if you could.

  • @josephpiskac2781
    @josephpiskac2781 Год назад +5

    I read one examination of the Shuttle that presented the difficulty and expense of reusable engines was tremendously underestimated. That the engines never achieved their life expectancy. Basically a regretted decision.

  • @firefly4f4
    @firefly4f4 Год назад +67

    I somewhat bristled when you called the core stage a modified shuttle main tank, because it's really not. The SLS carries its payload on top of the tank and thrust from the bottom, rather than both being to the side like with the shuttle. This means that although visually similar, the core tanks actually have very little in common with the shuttle tanks as the forces through them are so different. The diameter and basic shape is about all that's preserved, with even the insulation, despite the colour, being different. This tank redesign is reported to be one of the major reasons for the delays and cost overruns of the program.
    It would have been more appropriate to mention the boosters, as those actually do/did contain segments from actually shuttle launches. They too have been redesigned somewhat - being now 5 segments instead of 4, new insulation, and modified solid propellant mixture - but as stated actually do have former shuttle components that previously were recovered and now are being discarded.

    • @robertfousch2703
      @robertfousch2703 Год назад +2

      Exactly.

    • @KirtFitzpatrick
      @KirtFitzpatrick Год назад +6

      Nit picky nit picking. I'm sure Paul is aware of that given the depth of coverage in other areas. Probably oversimplified that section since this is a video on the engines and not the core stage itself.

    • @dziban303
      @dziban303 Год назад +3

      I thought most of the stringers and frames were basically identical?

    • @dr4d1s
      @dr4d1s Год назад +5

      @@KirtFitzpatrick If he did then why didn't he say it then instead of what he did? People who are into rockets are pedantic because in rocketry being pedantic matters.

    • @BTW...
      @BTW... Год назад +8

      @@dr4d1s Like you work in the industry and it matters? Proud to be pedantic? It's not a great claim considering what it really means.

  • @craigtanner6916
    @craigtanner6916 Год назад +7

    I absolutely love your videos! Thanks for all the hard work bringing these videos to us!

  • @bgebbq314
    @bgebbq314 Год назад +4

    Excellent video and historical perspective of the renowned SSME/RS25.
    Thanks for the mention of the Narloy Z !

  • @lightkeeper917
    @lightkeeper917 Год назад +2

    Always, packed with interesting information. Thank you.

  • @AspynDoesStuff
    @AspynDoesStuff Год назад +5

    This might sound a bit nitpicky, but the core sls stage is not at all a refurbished shuttle external tank. Shuttle external tanks were never recovered and the core is made out of a different metal all together. It just has the same foam insulation

    • @tedmoss
      @tedmoss Год назад +1

      But we want to call it reusable!

  • @marijnmolenaar2848
    @marijnmolenaar2848 Год назад +2

    Hope your well Paul! Again another insightful video

  • @AlexSchendel
    @AlexSchendel Год назад +73

    SLS is certainly an incredible vehicle to watch and will carry NASA into a new age of exploration, but man it really is incredible to see Boeing take Space Shuttle engines, Space Shuttle tanks, Space Shuttle SRBs, and an upper stage that is taken from the Delta IV Heavy... And then take 11 years and $20bn to find the right way to bolt them together... Great job there Boeing.

    • @billymania11
      @billymania11 Год назад +14

      There were a number of strange decisions relating to the Senate Launch System (SLS) rocket.

    • @tma2001
      @tma2001 Год назад +8

      oh and recover none of it - even the solid rocket casings had parachutes with the Space Shuttle.

    • @AlexSchendel
      @AlexSchendel Год назад +8

      @@tma2001 probably because they learned that recovering and refurbishing spent SRBs from the ocean where they get heavily corroded with salt water is actually more expensive than building them new lol. Would've been cool if they did it Energia style and had deployable wings so they could just fly back to KSC haha. Not to mention it would've been such an awesome sight to behold.

    • @ericmatthews8497
      @ericmatthews8497 Год назад +4

      The core stage is not a Space Shuttle tank..

    • @AlexSchendel
      @AlexSchendel Год назад +5

      @@ericmatthews8497 I'm aware that it is stretched and heavily modified to have enough structural support too carry Orion and the upper stage as well as support the force of 4 RS-25s, but are we really saying that it is acceptable that it took 11 years to make this modification? Heck, even longer when you consider the development of Ares V. NASA gave Boeing a scathing report on Boeing's atrocious project management for a reason.

  • @dannyv.6358
    @dannyv.6358 Год назад +1

    Happy to see uploads again!!!
    You're da best 👌

  • @chestersnapdragonmcphistic579
    @chestersnapdragonmcphistic579 Год назад +4

    In the same way that a Falcon 9 Expendable or a Falcon Heavy core booster is discarded for maximum performance, the SLS must extract maximum performance from every launch or it just isn't worth the cost. A series of smaller reusable rockets could do the job cheaper than a much more expensive reusable SLS. It's really for high energy missions that can't be split up into multiple launches.

  • @kentaylor6563
    @kentaylor6563 Год назад

    Good to see you back. Thanks for all the info.

  • @thomasackerman5399
    @thomasackerman5399 Год назад +4

    All right, right off the bat. The SLS core fuel tanks are NOT a modified Space Shuttle ET, they're almost a brand new design and use completely different tooling to build.

    • @dogsbd
      @dogsbd Год назад

      True. But SLS was sold to congress, originally oh so many years ago, as using "modified" shuttle hardware as doing so would be economical. We have all seen how that turned out.

  • @barryhall7
    @barryhall7 Год назад +28

    It is shocking that they just dump those RS engines

    • @barryhall7
      @barryhall7 Год назад +7

      @@sourandjaded2586 I would say that the bottom of the sea is definitely dumped.

    • @atomicshadowman9143
      @atomicshadowman9143 Год назад +2

      I guess gathering dust in a museum is better 🙄

    • @RCAvhstape
      @RCAvhstape Год назад +6

      @@atomicshadowman9143 I prefer "reused dozens of times, then retired to gather dust in a museum", which is what they were built for.

    • @nagualdesign
      @nagualdesign Год назад +2

      @@RCAvhstape I prefer "reused dozens of times, then used to send astronauts to the Moon". They were not built to gather dust in a museum.

    • @RCAvhstape
      @RCAvhstape Год назад +1

      @@nagualdesign Once they reach a number of flights you have to retire them. Nothing lasts forever.

  • @7891ph
    @7891ph Год назад +24

    If I remember correctly, the biggest reason that the SSME's were so expensive is because of the amount of power the made vs what they weighed. At the time, pound for pound of weight, they were the most powerful engine's on the planet. Another article I read compared them to SpaceX's current Falcon 9 engine's, and they came out on top for power to weight by a good sized margin. It's the old drag racers dilemma; powerful, cheap, reliable. Three choices, you can only pick two. What's your decision???

    • @eyeborg3148
      @eyeborg3148 Год назад +2

      Not really - the thrust to weigh ratio on the RS-25 is not that high, Falcon 9’s Merlin engines have a much higher thrust to weight ratio. Part of the reason is just down to fuel - Falcon 9 uses kerosene as opposed to hydrogen, which on a volume basis produces a lot more energy per unit burned.
      The reason the RS-25 is expensive down to several factors - First it is very efficient, using a more fuel rich closed cycle design. Second, it is designed to be reused, so it is built with that in mind, and components are chosen for longer life than disposable engines. Also, it is regeneratively cooled as opposed to ablatively cooled, like cheaper disposable hydrogen engines like the RS-68. Third, it is designed to be efficient at a wide range of altitudes, from sea level to the vacuum of space. This means there are significant complexities in terms of nozzle design, in particular the engine bell of the RS-25 can change shape/expansion ratio depending on altitude.

    • @simongeard4824
      @simongeard4824 Год назад +7

      I think the main reason they're so expensive is simply that they were complex engines made in very small production runs, so you'd never get anything resembling economies of scale, and you'd never pay down the R&D costs.
      Compare with Raptor 2 - it's near enough the same thrust as an RS-25 for half the mass, and even before one has ever flown, SpaceX have manufactured more of them than the total number of RS-25s ever built. And even if the unit costs for Raptor end up being ten times the aspirational figures they've claimed, that's still nearly one hundredth of the price of a single RS-25. And I'm pretty sure that the reason for that is almost entirely because SpaceX are designing it to be manufactured in vast numbers... building more in a year than Aerojet did in fifty years.

    • @richardbaird1452
      @richardbaird1452 Год назад +1

      @@eyeborg3148, Do you have a reference for that last point (changing shape/expansion ratio based on altitude)? My understanding is that the RS-25 engine bell is static is shape. It was designed to be slightly sub optimal in vacuum performance only to the degree necessary to prevent flow separation at sea-level, not that the shape/expansion ratio changes in any significant way due to altitude (excluding slight changes due to thermal expansion which happens to all nozzles). This was deemed acceptable as the majority of the run time was at higher altitudes where vacuum optimization would the primary goal.

    • @eyeborg3148
      @eyeborg3148 Год назад +1

      @@richardbaird1452 Actually you’re right, it doesn’t change shape, I misremembered things.

    • @nutsackmania
      @nutsackmania Год назад

      @@eyeborg3148 Do you know what specific impulse is? You should try figuring that out before you pop off.

  • @What2Have4Dinner
    @What2Have4Dinner Год назад +2

    Great video, glad to see you back at it man. Hope your doing better

  • @ManyTriangles
    @ManyTriangles Год назад +12

    I love the flashy title sequence. Really conveys that some epic learning is about to happen.

    • @moonwalkhi
      @moonwalkhi Год назад

      It summarises the video well.

    • @emirvmendoza
      @emirvmendoza Год назад

      I prefer the old title sequence, with a voiceover whispering "Curious Droid"

  • @IvanQuaglia
    @IvanQuaglia Год назад +4

    I guess there is a good reason behind it: maybe the fact of being very reliable even being reusable made it overengineered and quite expensive, so using the proven design can be made cheaper one use but reliable anyway, and is cheaper to make one than to recover and use it again

    • @miguellopez3392
      @miguellopez3392 Год назад

      SpaceX is testing out their Raptor 2 engine which is re usable and being produced at a rate of 7 per week.

  • @marvintpandroid2213
    @marvintpandroid2213 Год назад +15

    There were some close calls on the shuttle main engines, including holes in the heat exchanger / rocket bell.

    • @tangydiesel1886
      @tangydiesel1886 Год назад +1

      I can't remember if it was the cooling channels or the injectors, but they would plug the ones that didn't pass inspection between flights. The plug came dislocated during one of the flights and punched holes in different places on its way out.

    • @laz7354
      @laz7354 Год назад +2

      This, 100%. This is why reuse is, when one blows up, way more expensive than new.

  • @BlackEpyon
    @BlackEpyon Год назад +2

    Those RS-25's should have gone to museums. A team had redesigned the F-1 to be made using modern processes, but ultimately Congress had to keep their defence contractors in the black by having them take apart and redesign these re-usable RS-25's to be "disposable," and thereby saving... What, exactly? They could have built NEW engines for how much it cost them to redesign the RS-25's, not to mention that the F-1B's would have produced FAR more thrust!
    Just a colossal waste of money.

  • @morzee94
    @morzee94 Год назад +5

    It’s a good day whenever you upload :)

  • @brentboswell1294
    @brentboswell1294 Год назад +6

    It's a shame that they don't even try to recover the SRB's, because the shuttle version was totally designed for that. The parachute package hardly added any weight to the boosters. The 5 segment version used for SLS was actually fully developed during the Shuttle era, but never flew due to the cancelation of the Space Shuttle program after the Columbia disaster .

    • @IstasPumaNevada
      @IstasPumaNevada Год назад +5

      It's not really a shame; refurbishment of the Shuttle boosters cost just about as much as buying new ones, so the reusability was basically pointless.
      What's really a shame is that these major aerospace companies with decades of history could have had fully-reusable, controlled-landing first stages by now if they had incentive to develop them, but since they get paid massive government contracts whether or not they innovate, they just don't innovate.

    • @steveaustin2686
      @steveaustin2686 Год назад

      @@IstasPumaNevada The technology for reuse wasn't there until recently. Now, ULA, Blue Origin, Rocket Lab, Relativity Space, etc are all working on reuse.

    • @nutsackmania
      @nutsackmania Год назад +2

      Refurbishment of the SRBs was not as expensive as building new ones, sorry. It wasn't nearly as cost efficient as they hoped, but you're just extrapolating the cliche.

    • @JB-kk4pv
      @JB-kk4pv Год назад +1

      @@steveaustin2686 Technology was not there because they chose not to develop it. Moon lander landed vertically and then took off, not too hard to see them extrapolating to powered vertical landing on earth, could have had by late 70's if not early 80's. IstasPuma above has it right.

    • @steveaustin2686
      @steveaustin2686 Год назад +1

      @@JB-kk4pv There were many attempts at making reusable spacecraft since Apollo. The Shuttle as the most famous and it cost more and was harder than they thought it would be. The DC-X used vertical landing as well in the 1990s.

  • @josephpacchetti5997
    @josephpacchetti5997 Год назад +4

    This is the question I had pondered before Artemis I launched, Why not reuse the engines, instead of letting them sleep with the fishes, well, your channel answered that question and many more, Thank You Curious Droid. 👍 subbed.

  • @ADVBear
    @ADVBear Год назад +3

    Fantastic, as usual. Thanks, Paul.

  • @markiangooley
    @markiangooley Год назад +6

    It’s amazing what you can do with antique parts one would expect to be in museums…

  • @spencerthompson1049
    @spencerthompson1049 Год назад +2

    Love when Paul talks engines!

  • @nick4506
    @nick4506 Год назад +6

    did any rs25s make it to the 50 mission design? i know they got kinda sketchy after w while with the little brass plugs in the combuster falling out and leaks in the nose cooling.

  • @pratyushojha
    @pratyushojha Год назад

    Nice to see you back.

  • @lostcarpark
    @lostcarpark Год назад +6

    Not sure the shuttle could really need considered reusable. Refurbishable might be more accurate.

  • @jefffiore7023
    @jefffiore7023 Год назад

    Incredible video as usual - greetings to you Paul from Houston Tx!

  • @bigratkiller1
    @bigratkiller1 Год назад +8

    The Shuttle main tank wasn't reusable and was never recovered. The SLS tank is similar in colour only as it's a completely new tank but built at the shuttle tank factory

    • @blackhatfreak
      @blackhatfreak Год назад +1

      No shit, it was clear he meant reusable in design. I knew that's what he meant.

    • @bigratkiller1
      @bigratkiller1 Год назад +2

      @@blackhatfreak No, he said is was modified showing real reusability. Go listen

    • @steveaustin2686
      @steveaustin2686 Год назад +3

      @@bigratkiller1 Yeah, it's not like they could just slap engines on the External Tank and call it a day. There were major changes for the core stage to have engines on the bottom and the second stage plus payload on top.

    • @rileyk99
      @rileyk99 Год назад

      People keep calling it a tank.
      It's a rocket.

  • @larryrich327
    @larryrich327 Год назад

    Good to see you and your videos again

  • @ericmatthews8497
    @ericmatthews8497 Год назад +13

    Bottom line.. It's cheaper to throw them away than to develop a way to recover them from near orbital velocities. And any reusability components added, would subtract from the performance of SLS to lunar orbit. Nothing is ever truly reusable without a trade-off. That is why Starship will need nearly twice the sea-level thrust and multiple launches with orbital refueling to reach a lunar orbit. Those are some FREAKING BIG trade-offs that might just fail completely.

    • @steveaustin2686
      @steveaustin2686 Год назад +3

      Exactly

    • @FrankyPi
      @FrankyPi Год назад

      Yep, the whole "holy grail of rocketry and reusability" thing is just another myth that Musk is propagating for his cult of personality and its followers. There is no such thing, there will always be drawbacks and a limited optimal use case. It remains to be seen whether Starship will even make it beyond LEO, and if it does it's guaranteed that it will come nowhere close to the grand goals and expectations.

    • @jamese9283
      @jamese9283 Год назад +1

      You stated everything very well. I am expecting NASA choosing Starship HLS to turn out to be a huge mistake.

  • @Memeieli
    @Memeieli Год назад

    Absolutely love your channel Curious Droid.

  • @dvusGishzida
    @dvusGishzida Год назад +3

    There was actually another "failure" that seems to have been "scrubbed" from official history. There was a non-critical failure on STS-4 of a solid titanium High Pressure Fuel Pump first stage impeller. The impeller had three tight tolerance "lips" so that as the pump got up to operational speed the impellers would axially expand to seal against a teflon-like hi-temp resistant labyrinth seals in each stage of the pump. 13 seconds before MECO the first stage impeller "broke"" Two of the three labyrinth seal lips of the impeller about 3 to 5 inches long broke into pieces. The broken pieces were fed into the other two impellers of the HPFTP resulting in a sudden "white plume" in the engine exhaust as the pieces were turned to titanium powder then "burned" by the engine. Mission Control was aware that something had happened but the engines appeared "nominal" so they did nothing.
    How do I know this? I was part of the Quality Assurance team at Rocketdyne and inspected the damaged impeller once the pump was returned and disassembled at our Canoga Park manufacturing facility. The question NASA wanted answered was the failure unforeseeable or was it caused by something in the manufacturing process. The impellers were made from solid titanium castings and then machined into high precision impellers with labyrinth seal lips . Normally these were "refurbished" after each flight but STS-4 was considered a "test" flight and the engines had not flown before,
    After a review of all the evidence both Rocketdyne and NASA concluded that there was a undetectable flaw in the casting used to make this impeller and that the failure was unforeseeable.
    At one point in time there was a video of the event available on the Internet but I can't seem to find it. All of the STS-4 Launch videos I can find end before the failure occurred.
    Fun Fact: Each of the SSME engine controllers uses three MilSpec 80286 CPUs as the "brains." of its"Tell-Me-Three-Times" Engine Controller.

    • @faroncobb6040
      @faroncobb6040 Год назад

      Interesting, I was only aware of four near misses other than this. The first shuttle flight lost a bunch of tiles and had a number of other serious issues, one of the pre disaster Challenger flights almost shut down all engines before an emergency override stopped them and would have resulted in a very dicey cross Atlantic abort scenario if not for the quick thinking of the ground crew, the heat shield damage on the return to flight mission after the Challenger disaster that only didn't destroy the orbiter because a steel antenna plate protected the aluminum frame, and the gold pellet incident that almost ripped enough cooling channels open to destroy an engine while the solid boosters were still running.
      Am I correct in thinking that the seals held in place by the three seal lips you are talking about were what prevented hot, high pressure hydrogen from being squeezed down the shaft to the oxygen pump? Because if that was the case then any failure of the third seal would have resulted in the engine blowing up dramatically, which would have been bad at 15 seconds before MECO, but would have been catastrophic had it happened earlier in the flight while the boosters were still going.

  • @daveherbert6215
    @daveherbert6215 Год назад

    Excellent video Paul

  • @top6ear
    @top6ear Год назад +142

    They toss rocket engines like Frenchmen toss cigarette butts .

    • @th3ranger
      @th3ranger Год назад +17

      It’s hard to care when you’re spending someone else’s money

    • @derrekvanee4567
      @derrekvanee4567 Год назад +6

      Everyone loves mit when I do my french bit unfortuntately it doesnt work on the internet you need to make a finger moustacje and click your heels doing little dance jumps and bend your arms back and forth together in a push up motion and say with a thick french accent "Ho ho ho, oui oui oui. Cest la vyyyee! i am Ricardo Saison, and Im here to sayson these contracts make a lot of richardo dollers with contracts ho ho ho oui oui oui. bagette. perfume. cheese."

    • @mjproebstle
      @mjproebstle Год назад

      oui oui

    • @robm.4512
      @robm.4512 Год назад +4

      Do I detect a faint whiff of garlic about this thread?
      C’est assurement la possibilite, peut etre?
      I’ll get my beret. 😂

    • @jfinn3575
      @jfinn3575 Год назад +2

      ooo la la!

  • @EdgarKohl
    @EdgarKohl Год назад +1

    I'd take one as a souvenir.

  • @waynep343
    @waynep343 Год назад +4

    Thinking about surplus engines. What did the air force and the cia do with the spare engines from the YF 12s and SR71s did they scrap them. I read an article by willis hawkins years ago that the engines were good for 3,400 miles an hour but the heating of the airframe was the limiting factor. Thank you for this. I wondered how nasa was going to handle the limited number of SSMEs.

    • @wally7856
      @wally7856 Год назад

      The faster you go the narrower the mach cone, at about mach 3.65 the outer edges on the wings would make contact with the mach cone from the nose which would probably be disastrous so heating wasn't the only limiting factor.

  • @billyelliot4141
    @billyelliot4141 Год назад +1

    Thankyou mr droid sir. No one does it better. 🇮🇪✌️

  • @CybershamanX
    @CybershamanX Год назад +3

    Yeah, I'm a little sad seeing the shuttle boosters going up one last time. 😢

  • @spudgun889
    @spudgun889 Год назад

    Welcome back! I’ve missed you.

  • @DarrylHart
    @DarrylHart Год назад +5

    Video starts at 2:53

  • @billmcintyre3652
    @billmcintyre3652 Год назад +1

    Pretty amazing as huge and awesome the N-25 is the Saturn V still had a larger payload capacity. Everyone that worked on the Saturn V should be very proud of their almost unimaginable accomplishment. Only now are we edging close to what they pulled off in 1967. The Saturn V team were 55 years ahead of the technology curve.

  • @okankyoto
    @okankyoto Год назад +23

    The cost of the rocket engines is miniscule compared to the cost of developing a system to return them from orbit. With a flight rate mandated at 2/year, the breakeven is just not there for reusability on SLS components. Even the SRBs barely broke even in the 80s with monthly launches, and at lower rates cost more to recover than was saved by reusing them. Same situation with SLS- as its primarily a heavy lift rocket designed around maximum mass through TLI. Compare to the Starship HLS plan which requires 14 refueling launches to send it through TLI. And if Starship isn't 100% as cheap as hoped, it suddenly becomes a massive cost to have all those launches compared to expendable. Reusability has its place but its not a panacea for lower costs!

    • @Kowalski301
      @Kowalski301 Год назад +8

      Finally some common sense here. It's so depressing to see that many who firmly believe reuseable rockets comes with no downsides, especially at this launch rate.

    • @imarchello
      @imarchello Год назад +5

      the flight rate of 2 per year is because they have to make the rocket from scratch each time. With reusability they could fly more often.

    • @shannonkohl68
      @shannonkohl68 Год назад

      The caveat is that once you start manufacturing rocket fuel on the moon, it presumably will become much cheaper since cost to orbit should be much cheaper from there.

    • @thesteelrodent1796
      @thesteelrodent1796 Год назад +1

      currently Starship is just a giant money sink that is likely to end up costing so much to develop it will never pay for itself

    • @anthonypelchat
      @anthonypelchat Год назад +2

      You can clearly see the issue, but yet somehow think it's a justification for expending rockets. SLS can only fly once or twice a year because that is all that can be made. They have already had to cancel any launches other than Artemis for SLS as they just cannot make enough. And if the costs could be brought down as well by making it reusable, there is a lot of launches that could use it. And being reusable doesn't mean that you cannot have the rocket expended at some point. Being built to be expended only is just a waste and removes any options.
      Take Falcon 9 as an example. It's reusability has allowed it to be the cheapest ride to space per kg and cheapest altogether during rideshare missions. Plus it has allowed SpaceX to pursue another path that wasn't previously feasible. And yet after over 10 successful missions each, 2 boosters were finally expended for heavy, long distance missions that finally required it. They had more than paid themselves off many times over prior to finally being expended.
      And with Starship HLS, you tried to justify the SLS again with talking about it sending it's max mass to TLI on a single expended launch while HLS needs 14 refueling missions for it's max mass payload. However, you completely miss that HLS is sending around 3-4x more payload and not just going to TLI, but completely landing on the Moon and having enough fuel to return to lunar orbit. And that is all while being reusable. It could easily carry more to TLI than SLS while being completely expended. And it could be expended after paying itself off with numerous missions like Falcon 9 has. Being reusable gives you options that just don't exist with an expended launch platforms. And it reduces costs so much that you don't have to worry about launch cadence.

  • @stevehill4615
    @stevehill4615 Год назад

    Good video, got a question which is as mentioned for upcoming engines NASA is looking to produce cheaper disposable variations, what are the reasons for not using a "slimmed down" centre tank less engined rocket with 4 solid rocket boosters as opposed to the current configuration?

  • @100SteveB
    @100SteveB Год назад +22

    I would say that the main fuel tank on Artemis bares little in common with the tank used on the shuttle program, it is basically a complete redesign. The original tank was designed to take the thrust forces through mounts on the side of the tank onl;y, whilst the Artemis tank is designed to take thrust forces on both either side, and the bottom of the tank. The top of the tank is also totally redesigned, it now as to carry the load of the upper stages and capsule, whereas on the shuttle version it carried no load. But, like the shuttle version, the tank is not reusable. The other main part of the shuttle system that is being reused on Artemis are the side boosters, they have flown on previous shuttle missions. But for Artemis they have added an extra segment to increase the thrust output. But sadly, like the RS25 engines, they are not being recovered and reused, when of course on shuttle missions they parachuted back down to land in the Atlantic where they were recovered.

    • @sunspot42
      @sunspot42 Год назад +4

      The SRBs were never worth recovering in the first place, tho. Really on most rockets the only thing worth recovering are the engines themselves, assuming they’re built with reusability in mind. People forget just how insanely expensive the fuel is, and how valuable that last little bit of fuel is in an almost empty rocket. That can either be used to send considerably more cargo into orbit that launch, or consumed getting the rocket back to earth…where really the only component more valuable than that fuel are the engines.

    • @blackhatfreak
      @blackhatfreak Год назад

      It's literally a longer tank with engines at the bottom. The side boosters have not flown on previous shuttle missions as these are new 5 segment boosters while the older ones are 4 segmented ones.

    • @blackhatfreak
      @blackhatfreak Год назад +5

      @@sunspot42 Literally not true

    • @100SteveB
      @100SteveB Год назад +1

      @@blackhatfreak You are correct about the boosters, with the exception of one segment which flew previously on Atlantis they are new segments. Though i believe they plan to use further used segments in the future. I know Nasa have said they have several segments from shuttle flights that can be reused. And yes, the main tank is longer, along with completely redesigned upper and lower ends. About the only thing that remained the same was the diameter.

    • @sunspot42
      @sunspot42 Год назад +3

      @@blackhatfreak What is “literally not true”? The last bit of fuel in a rocket delivers the greatest delta v to the payload, because the fraction of fuel mass vs payload mass becomes most favorable for the last of the fuel. If you try to return the booster you need to either reserve a bunch of the most-valuable fuel to do it with, or add some other thing to the booster that also increases its mass (wings, parachutes, etc.) in order to get it safely back down on the ground.
      It’s a big reason why reusability has always been of questionable value, given the expense and complexity involved.

  • @simon8864
    @simon8864 Год назад

    I always look forward to your videos.
    All different and all excellent!
    Maybe you could do a video about how you make your videos

  • @heartofdawn2341
    @heartofdawn2341 Год назад +22

    _Each_ of those four engines costs about as much as a Falcon Heavy in expendable mode, and throwing the entire vehicle away on every launch feels like an anachronism when ever major rocket company is using (or at least planning to build) reusable systems.
    The shuttle was dangerous, impracticable, and required major refurbishment after each flight, but the SLS is still a huge step backwards.

    • @LukeBunyip
      @LukeBunyip Год назад +1

      In. A. Nutshell.

    • @steveaustin2686
      @steveaustin2686 Год назад +6

      The Falcon Heavy could barely lift the Orion, ESM, and ICPS when fully expended, but the aerodynamics of such a large stack on FH were an issue per former NASA Admin Bridenstine. Booster reusability is great, but has drawbacks.
      First, if you don't have a fast enough launch cadence, you can spend more on recovery equipment and personnel than you save by reusing the booster.
      Second, you take a payload hit for the recovery system on the booster. The Falcon 9 B5 can lift up to 22.8 tons to LEO when expended (SX), but only up to 16.7 tons when landed on a drone ship (B1069.2). Doing a Return to Launch Site (RTLS) landing, costs even more payload as you have a boost back burn to cancel the lateral velocity and return back to the launch site.
      Third, the higher and faster you go, the harder reusability is to perform. The heavier the dry-mass of your booster, the harder reusability is to perform.
      So with SLS launching once a year, eventually, the cadence doesn't really justify recovering the booster. Not to mention that it gets higher and faster than a Falcon 9 as the SLS core stage almost reaches orbit, making recovery MUCH more difficult. The SLS core stage is travelling well over 3 times as fast as the Falcon 9 booster and is well over twice as high as the Falcon 9 booster at MECO. The dry mass of the F9 booster is 22-25 tons while the SLS core stage is 85 tons.
      The SLS Block 1 can get Orion to the Moon, but not with the kind of payload hit like F9 has. The SLS Block 1B will send along a Lunar Gateway module with Orion, so it really can't take the payload hit either.
      SLS started design work in 2011, 4 years before SpaceX landed the first booster and almost 6 years before they reused a booster.

    • @TheSwissGabber
      @TheSwissGabber Год назад +3

      ​@@steveaustin2686 Did you look at the numbers? the SLS (2 billion per launch) is 20x more expensive then FH, with 50% payload. You could launch 13 Falcon heavy for one SLS.

    • @steveaustin2686
      @steveaustin2686 Год назад +5

      @@TheSwissGabber Did you miss the point that the Falcon Heavy could not get Orion and the ESM to the Moon? The whole point of SLS. Rocket Lab's Electron is much cheaper than the Falcon Heavy, that does not mean that the Electron will replace the Falcon Heavy.

    • @heartofdawn2341
      @heartofdawn2341 Год назад

      @@steveaustin2686 those projects were built specifically to give SLS something only it could do. A moon project with FH could have been viable if they did it differently, and in a much cheaper manner. But then they would not have SLS for what it _really_ is for; a pork barrel project to create jobs and keep members of congress' constituents happy so they can remain in power, and to shove a lot of cash in Boeing's direction

  • @bagofholding
    @bagofholding Год назад +13

    The simple answer that I'm not sure was even mentioned during this video was that these engines are now attached to the tank that was always thrown away every launch instead of attached to a space plane that can glide back.

  • @tez6693
    @tez6693 Год назад

    Always love your videos. Great job.

  • @saxus
    @saxus Год назад +5

    There are some mistake in the video: first, the tanks aren't modified External Tanks, they're clean sheet design. It have different internal structure, different alloy, etc. The diameter is same and it both used SOFI, but that's all. Because it holds load on top instead of side had to change everything.
    Also it may Congress wrote in stone that NASA should use solids and RS-25 but when the SLS program have been started it started with two different teams: one who evaluated the LH2 based options and one who the Kerolox options. They even investigated Russian RD-180 based options too next to modernizes F-1B based options.

    • @simongeard4824
      @simongeard4824 Год назад

      Yeah, the fuel tank was supposed to be ET derived, but by the time they'd "modified" the design to meet the new requirements, the only thing that was still common was the colour...

    • @saxus
      @saxus Год назад

      @@simongeard4824 nope, the whole SLS was clean sheets from day 0, they just decided to use solids and RS-25 because that was who gives better TLI performance for this project. But the given engineering and economic restrictions lead in the same direction in some cases. But the tanks was clean sheet. SLS is eventually a merger of Ares V and DIRECT/Jupiter but not based on. There were a lot of different and really diverse concepts. Just check this: www.nasaspaceflight.com/wp-content/uploads/2018/04/2018-04-11-184524.jpg

  • @fatboyrowing
    @fatboyrowing Год назад

    Feeding the algorithm here. I love your well researched and well presented content. Bravo!

  • @nagualdesign
    @nagualdesign Год назад +11

    They're not throwing them away, they're putting these retired/redundant engines to good use.

    • @masterpython
      @masterpython Год назад +1

      Like they do with ICBMs.

    • @nagualdesign
      @nagualdesign Год назад

      @@masterpython 😆

    • @dannyarcher6370
      @dannyarcher6370 Год назад +1

      Once. And then they're throwing them away.

    • @masterpython
      @masterpython Год назад +1

      @@dannyarcher6370 so they should store and maintain them until a new shuttle is developed?

    • @simongeard4824
      @simongeard4824 Год назад

      @@masterpython They literally took some of them out of museums to be refurbished, so that they could be used one more time and thrown away...

  • @kenjackson5685
    @kenjackson5685 Год назад +1

    Your usual high standard Paul....1st class... thanks for sharing

  • @brianbarrett2487
    @brianbarrett2487 Год назад +3

    Imagine being asked to give 110%, you can literally respond with "I can do 109% forever" and they drop you in the ocean. =/

    • @laz7354
      @laz7354 Год назад

      115% ...and safely. One cheap corporate reusable failure and reusability will be synonymous with unnecessary risk.

  • @Chuzo1946
    @Chuzo1946 Год назад

    I love the cool shirts you wear, awesome video as always!

  • @greggesaman535
    @greggesaman535 Год назад +7

    The only justification for the SLS approach is -politics and retention of the shuttle worker force in home districts - no matter the cost. Mission accomplished.

    • @TheEvilmooseofdoom
      @TheEvilmooseofdoom Год назад

      @@MrWolfstar8 No, you dont' actually understand what's going on or how things work. Try again, this time, try informing yourself a little. Re-read Gregs post, he has a clue.. the one thing you lack.

  • @gregzarkodimos9711
    @gregzarkodimos9711 Год назад

    The headline 'Disposable heroes' is so... metal, if you catch my drift

  • @abbeyhall4624
    @abbeyhall4624 Год назад +21

    It is such a massive shame about the forthcoming disposability by NASA. But I guess that is par for the course ATM until the other systems become common place.

    • @SlartiMarvinbartfast
      @SlartiMarvinbartfast Год назад +1

      NASA's rockets are a politically driven enormous waste of money. Say what you like about Musk, but at least SpaceX (and others) see the major benefits in major reusability.

    • @mrb.5610
      @mrb.5610 Год назад +4

      It makes sense. You want as much payload capacity as possible - landing the first stage a la SpaceX reduces payload as it adds complexity and weight for the landing system plus fuel for the 'suicide' burn.
      And the engines probably weren't designed to be reignited - so this slso may be a factor.

    • @derrekvanee4567
      @derrekvanee4567 Год назад +2

      People say "spacex shows how much out of tune and antique nasa is" and its true I must say, but spacex hasnt had a orbital starship at all let alone crew rated to the moon. But it is sucha waste I think its just because somr rich company ceo's lobby so they can build extra disposable engines. If we INVENTED and INNOVATED like the gemini mercury and apollo missions which gave us a HUGE amount of the things we take for gtanted in modern life ike mylar and computers today instead of using 50yo hardware thinkl of what we could accomplish!

    • @SecretRaginMan
      @SecretRaginMan Год назад

      @@mrb.5610 Starship is designed to be refueled so it can take tens of tons of payload to the lunar surface. It is able to put more payload on the surface than any other lander proposed. There is a reason why a certain Senator (Richard Shelby) threatened funding to ULA over the word "depot". Refueling in orbit, which was a concept and proposal long before SLS, reduces SLS to obsolescence quite thoroughly.
      Current heavy lift rockets like the retiring Delta IV Heavy, upcoming Vulcan Centaur and New Glenn, and current Falcon Heavy make monolithic launches like SLS unnecessary. FH is $150M for 64 tons to LEO. Could launch sixteen times for one SLS + Orion mission ($4B according to NASA's OIG). Even DIVH at $400M could launch ten times, or thirteen times at $300M.
      On-orbit assembly and fuel depots are the future, not SLS.

    • @laz7354
      @laz7354 Год назад

      Single use is safer.

  • @PratabAli
    @PratabAli Год назад

    The thumbnail preview image looked like a row of Daleks. 😄

  • @tonyb3629
    @tonyb3629 Год назад +3

    To fly a fully disposable rocket in 2022 is utter madness, and even more crazy is that NASA take engines designed to be re-usable and dump them after one launch. No wonder SLS costs £3-4B per flight, and that's still using a large amount of SS tech!

    • @steveaustin2686
      @steveaustin2686 Год назад

      Booster reusability is great, but has drawbacks.
      First, if you don't have a fast enough launch cadence, you can spend more on recovery equipment and personnel than you save by reusing the booster.
      Second, you take a payload hit for the recovery system on the booster. The Falcon 9 B5 can lift up to 22.8 tons to LEO when expended (SX), but only up to 16.7 tons when landed on a drone ship (B1069.2). Doing a Return to Launch Site (RTLS) landing, costs even more payload as you have a boost back burn to cancel the lateral velocity and return back to the launch site.
      Third, the higher and faster you go, the harder reusability is to perform. The heavier the dry-mass of your booster, the harder reusability is to perform.
      So with SLS launching once a year, eventually, the cadence doesn't really justify recovering the booster. Not to mention that it gets higher and faster than a Falcon 9 as the SLS core stage almost reaches orbit, making recovery MUCH more difficult. The SLS core stage is travelling well over 3 times as fast as the Falcon 9 booster and is well over twice as high as the Falcon 9 booster at MECO. The dry mass of the F9 booster is 22-25 tons while the SLS core stage is 85 tons.
      The SLS Block 1 can get Orion to the Moon, but not with the kind of payload hit like F9 has. The SLS Block 1B will send along a Lunar Gateway module with Orion, so it really can't take the payload hit either.
      SLS started design work in 2011, 4 years before SpaceX landed the first booster and almost 6 years before they reused a booster.

  • @jameswarner7435
    @jameswarner7435 Год назад

    Just when I thought I had seen the most impressive shirts in existence, there he goes and raises the bar again... Jolly good show!

  • @voneschenbachmusic
    @voneschenbachmusic Год назад +20

    It doesn't make sense from an efficiency or cost perspective but makes lots of sense in terms of Congress requiring this stuff to direct federal funding to their states. It's a giant welfare project for the massive industrial complex built to support the shuttle system. Meanwhile new space will continue to make strides and all of this stuff will become increasingly irrelevant and expensive. It would be easily within the technical capabilities of old space to build a heavy lift reusable system but they are too busy sucking that sweet sweet cost-plus government teat to ever change.

    • @masterpython
      @masterpython Год назад

      So you propose these engines be stored and maintained until a new shuttle is developed? Put in museums or the on the lawns in front of them, cut into pieces and melted down for scrap? All kinds of old hardware gets repurposed.

    • @dogsbd
      @dogsbd Год назад +2

      @@masterpython Old hardware gets repurposed if it is economical to do so. A 20+ billion dollar program to achieve a handful of SLS launches using a handful of SSME's doesn't qualify as economical no matter how you look at it. Yes, it would have made more sense to turn those SSME's into museum pieces.

  • @Chef_PC
    @Chef_PC Год назад +1

    It really blows me away that there weren’t any computer-aided design or physics simulations that we have now, and these are still some of the most technically advanced rocket engines we publicly have. All the engineering and mechanical designs were done with pencil on paper and the equivalent of a pocket calculator.

    • @TheEvilmooseofdoom
      @TheEvilmooseofdoom Год назад +2

      Nonsense. They had CAD and simulations in the 70's and 80's. Nothing like we have now, but it did exist.

    • @Chef_PC
      @Chef_PC Год назад +1

      @@TheEvilmooseofdoom You're right. I was thinking (not out loud, obvs) about the older engines built and designed in the 50s & 60s. I could have been clearer.

  • @Haploanddogs
    @Haploanddogs Год назад +3

    Short Answer? The senate

  • @frogenthusiast235
    @frogenthusiast235 Год назад +1

    I really enjoy and appreciate your content, it’s always a breath of fresh air at the end of a complex day, thank you

  • @xliquidflames
    @xliquidflames Год назад +6

    What a great video. I think most people don't realize SLS is made of Shuttle parts. They know it looks familiar. It has an orange tank and the two white solid boosters but they probably assume that's just what NASA rockets look like.
    Personally, I don't think they'll make it through developing the RS25F before Starship proves it's viability. I don't know if SLS will be completely canceled but it will at least be scaled way back. They might just use up what engines they have left and then let Starship take over all duties. If Starship can make orbital refueling a reality, there'll be no need for SLS.

    • @robertmiller9735
      @robertmiller9735 Год назад +2

      SLS is bound to be cancelled Starship or no Starship. We better hope Starship development has gone far enough by then.

    • @HankScorpio64
      @HankScorpio64 Год назад

      I mean I didn't know that but it doesn't surprise me especially since NASA is one the more cash strapped agencies of the US gov't and is normally the first to get budget cuts whenever anyone mentions cutting funding to something. (Though we are just as fine spending more money on the DoD and military even though the contractors are the same. Figure that one out) using space shuttle parts would make sense since there already infrastructure in place and the limited money that is there can go into more important components that do need some thought and design

    • @newq
      @newq Год назад +3

      Honestly, I kinda doubt this. Starship requires multiple refueling missions for TLI and deep space, which negates any cost benefits from being reusable. It'll be a hard sell for NASA. Starship probably has a better niche in heavy lift LEO launches. At the moment, SLS really is the most viable option for the moon and beyond.

    • @nachobasket
      @nachobasket Год назад +1

      @@robertmiller9735 The government has no plans to cancel SLS. As long as they keep funding it, it will fly. Just because it is expensive doesn’t mean it will be cancelled. NASA can afford it and will keep construction going on it.

    • @laz7354
      @laz7354 Год назад

      Personally, I wouldn't count on Moosk.

  • @rickestabrook4987
    @rickestabrook4987 Год назад

    Another great video. Thanks!

  • @steveaustin2686
    @steveaustin2686 Год назад +4

    Booster reusability is great, but has drawbacks.
    First, if you don't have a fast enough launch cadence, you can spend more on recovery equipment and personnel than you save by reusing the booster.
    Second, you take a payload hit for the recovery system on the booster. The Falcon 9 B5 can lift up to 22.8 tons to LEO when expended (SX), but only up to 16.7 tons when landed on a drone ship (B1069.2). Doing a Return to Launch Site (RTLS) landing, costs even more payload as you have a boost back burn to cancel the lateral velocity and return back to the launch site.
    Third, the higher and faster you go, the harder reusability is to perform. The heavier the dry-mass of your booster, the harder reusability is to perform.
    So with SLS launching once a year, eventually, the cadence doesn't really justify recovering the booster. Not to mention that it gets higher and faster than a Falcon 9 as the SLS core stage almost reaches orbit, making recovery MUCH more difficult. The SLS core stage is travelling roughly 3 times as fast as the Falcon 9 booster and is well over twice as high as the Falcon 9 booster at MECO. The dry mass of the F9 booster is 22-25 tons while the SLS core stage is 85 tons.
    The SLS Block 1 can get Orion to the Moon, but not with the kind of payload hit like F9 has. The SLS Block 1B will send along a Lunar Gateway module with Orion, so it really can't take the payload hit either.
    SLS started design work in 2011, 4 years before SpaceX landed the first booster and almost 6 years before they reused a booster.

  • @richardbriansmith8562
    @richardbriansmith8562 Год назад

    Awesome Video

  • @T3H455F4C3
    @T3H455F4C3 Год назад +3

    Reuse-ability is great as long as it doesn't cost or weigh too much. At this point launching stuff into near-earth orbit favours reuse-ability. However when talking about escape velocity... Probably not.

    • @TheEvilmooseofdoom
      @TheEvilmooseofdoom Год назад

      What nonsense.

    • @anthonypelchat
      @anthonypelchat Год назад

      That's just short sighted. Getting into Earth orbit requires more deltav than is required to get from Earth orbit to just about anywhere else in the solar system. Being reusable gives you options that expended does not. For example, instead of using the launch vehicle itself to send a payload to the moon or Mars, you could send a heavier payload to LEO that has it's own highly efficient engines that then goes out further.

    • @T3H455F4C3
      @T3H455F4C3 Год назад

      ​@@anthonypelchatIn the context of sending cargo to the moon I would agree with you. But no matter how you cut it, carrying extra fuel and whatnot is going to cut into your payload. Furthermore if your sending people to the moon you want all the delta v you can get.
      Making the trip longer than necessary is dangerous to the crew. Highly efficient engines are not your friend in this scenario.

    • @T3H455F4C3
      @T3H455F4C3 Год назад

      @@TheEvilmooseofdoom A very concise critique. I'm afraid I have no rebuttal.

    • @anthonypelchat
      @anthonypelchat Год назад

      @@T3H455F4C3 Highly efficient engines are always your friend in long distance missions. There are some that wouldn't be because they are too weak, but that doesn't mean ALL highly efficient engines are that way. Plus, if you are carrying dead weight, that slows you down and waste dv.
      When you are reusing launch vehicles, you gain options. It can be as simple as expending a booster that has already flown, or as complicated as making a better overall design in orbit instead of cramming everything into one vehicle. But if you don't have a reusable option, then you have no decent options available as you are now limited by both build times and costs for the launch vehicle.

  • @PetesGuide
    @PetesGuide Год назад +1

    Are any RS-25Ds going to be left for museums or engineering study? Are any of the earlier RS-25 models left?

  • @bigmac85987
    @bigmac85987 Год назад +5

    The shuttle’s external tank was not reusable. The big orange tank was discarded after every launch to burn up during reentry. The SLS orange fuel tank is based on the shuttle’s external tank, but has a great deal of changes and improvements.

  • @Study49
    @Study49 Год назад

    Thank you and Blessings!!

  • @sxmolin
    @sxmolin Год назад

    Great video! A lot of cool info.

  • @mikecarr4178
    @mikecarr4178 Год назад +3

    The shuttle never came close to meeting it's goals on launch frequency or affordability. Was insisting on reusable launch systems the way to go then? (I know there were a lot of compromises due to funding as well.)

    • @michaelnash2138
      @michaelnash2138 Год назад +1

      I've read (IIRC it was in a book called "Halfway to Anywhere" by Harry G. Stein. A good read. Clarke said it, too, though.) that the space shuttle was meant to be the DC-3 of space but after congress got ahold of it it turned into the DC-1 1/2. True reusability would have put the price to orbit via a TRUE shuttle at maybe $1000/lb. instead of the $10,000 it is now.

  • @steveshoemaker6347
    @steveshoemaker6347 Год назад

    Thanks Paul 🙏👍

  • @markbeards4441
    @markbeards4441 Год назад +6

    They could be used to make rain machines for the most dry farming land.

    • @robrod7120
      @robrod7120 Год назад

      Thats not how this works. The amount of energy and - get this - WATER you need to make rocket fuel makes it entirely unrealistic and unreasonable. It would cost billions to make a single raincloud. Irrigation meanwhile actually makes sense.

  • @zaheer4024
    @zaheer4024 Год назад

    Best RUclips channel!

  • @brick6347
    @brick6347 Год назад +23

    Sls is a bit like a post war ocean liner: big, impressive, completely obsolete.

    • @mrb.5610
      @mrb.5610 Год назад +1

      And what would you suggest instead ?

    • @lordgarion514
      @lordgarion514 Год назад

      @@mrb.5610
      How about anything that's not half reused parts and tech costing over $4 BILLION epr launch?
      Can't post links, so I'll paste this.
      "Appearing before a House Science Committee hearing on NASA's Artemis program, Martin revealed the operational costs of the big rocket and spacecraft for the first time. Moreover, he took aim at NASA and particularly its large aerospace contractors for their "very poor" performance in developing these vehicles.
      Martin said that the operational costs alone for a single Artemis launch-for just the rocket, Orion spacecraft, and ground systems-will total $4.1 billion. This is, he said, "a price tag that strikes us as unsustainable."
      "If one were to amortize development costs over 10 flights of the SLS rocket and Orion spacecraft, the $4.1 billion figure cited by Martin would easily double."
      Then, unprompted, Martin continued to criticize the programs set up by Congress to fund the rocket and spacecraft. House and Senate members told NASA to use "cost-plus" contracts, which ensure that companies involved in the development and operation of these systems receive all of their costs, plus a fee. This tends to disincentivize timely work completed within a set budget. (Remarkably, NASA was told to continue using cost-plus contracts even after the development program.)
      "We saw that the cost-plus contracts that NASA had been using to develop that combined SLS-Orion system worked to the contractors' rather than NASA's advantage," Martin said."
      "In fact, key members of Congress have been critical of NASA every time the agency has tried to break free of cost-plus contracting and use a more commercial approach through fixed-price contracts."
      How about anything that's not a direct ripoff of our money?

    • @om617yota8
      @om617yota8 Год назад

      @@mrb.5610 I would suggest government step out of the space launch biz and let private industry take over.

    • @TheOwenMajor
      @TheOwenMajor Год назад +1

      @@lordgarion514 So you're just complaining?
      Being a critic is easy. And as SpaceX is finding out, making a heavy launch vehicle is tough.

  • @davidlobaugh4490
    @davidlobaugh4490 Год назад

    The only guy with better shirts than me. 😎 Well put together show.

  • @fangugel3812
    @fangugel3812 Год назад +10

    To understand NASA, one must understand that its primary function is to transfer taxpayer money to private contractors that do nice things for the people who control NASA’s budget. We are lucky that they still manage to do fantastic science.

  • @Pyrolonn
    @Pyrolonn Год назад +1

    I never thought about them just being dumped in the ocean. I do see some complaints about non-reusability. The lesson of the Space Shuttle? Reusability can be more expensive than disposability.

  • @steverpcb
    @steverpcb Год назад +3

    There were very strict requirements for the new homes for the shuttles so that they could be brought back into service if needed, now the SLS is throwing 4 of their engines into the sea after each launch :(

    • @steveaustin2686
      @steveaustin2686 Год назад +1

      No they weren't. The Shuttle's were decommissioned.

  • @Jakob_DK
    @Jakob_DK Год назад +2

    It is great that we are going back to the moon and beyond.
    Competition is a good thing.

    • @Jakob_DK
      @Jakob_DK Год назад

      @@martinr1834
      Yes our enemies may succeed in spreading devising, it seems they do

  • @DM-zs8go
    @DM-zs8go Год назад +3

    One word.
    Corruption!

    • @laz7354
      @laz7354 Год назад

      Agree. Government funding private corporate greed monsters like SpaceX is corruption at its max.

  • @Soldier4USA2005
    @Soldier4USA2005 Год назад

    Come for the shirt, stay for the knowledge.
    Another excellent video, my good sir.