21 thoughts on “NASA’s “Comically Big Moon Rocket””

  1. Even if SLS works as advertized, and even if it wasn’t costing obscene amounts, it’s still badly flawed. Even Block 2 won’t have the TLI capacity of SaturnV, even though it masses a lot more on takeoff, and has more thrust. The stage-and-a-half design is a poor choice, performance-wise. So, comically large, but with a smaller payload.

    The cost, though, would make it an abomination even if it had far better performance than SLS will.

    I also share the skepticism on a launch date. I’m wondering if they’ll even get to the green run next year. My current guess for a launch date is late 2025, if all goes well and the reported issues (such as leak concerns) prove unfounded.

    Any idea who is developing the GNC software for SLS? If it’s Boeing, expect both problems and delays, if the Starliner and 737 fiascoes are anything to go by.

    1. The silver lining to the SLS schedule slippage is that by the time it is flying crews (if it ever does) if something should go wrong, ala Apollo 13 etc, the crew can be rescued by a Starship.

    2. In the 1970’s and 80’s NASA rejected plenty of SLS type concepts as being too expensive, similar to the many designs for Saturn V derivatives.

      The core is too tall for any growth potential, given the height of the VAB. The core’s final velocity is too high for recovery and re-use without serious TPS, and it’s not TPS compatible because TPS won’t adhere to the core’s foam insulation. But it couldn’t land anyway because it uses RS-25’s. And on an on it goes. The SLS isn’t even a realistic starting point for a viable launch system.

      But I’m glad to hear they plan to test fire the engines by Thanksgiving. It highlights that they’re in an entirely different design-build-and-test universe from Starship. The closest hypothetical parallel I can think of would be if the British were still working on the R-100 and R-101 airships for passenger service in 1949 instead of 1929, just because the government was too bone-headed to cancel them.

      1. Actually, the British were doing something almost as silly in the late forties and early fifties. Look up the Bristol Brabazon and the Princess flying boat. Boeing and Douglas ate their lunch and the British aviation industry has never recovered.

        1. I went with the R-100 and R-101 because those would have had twenty years for people to realize they weren’t remotely fit for task. The Brabazon was a brand new idea that was simply a government ministry’s bad misreading of the emerging market.

          I’m saving a Brabazon analogy for New Glenn, New Armstrong, or perhaps even Starship, depending on how the space industry shakes out. There will certainly be many such dead-ends along the way, as some of the vehicles will be too expensive (an unbelievably high cost per seat), or too small (Orion to Mars!), or fly too infrequently, or be too high risk, etc. The Brabazon would’ve been viable if not for speed jump of both turboprops and early jets, whereas the R-100 and R-101 series airships would fail on pretty much all conceivable commercial grounds, losing to virtually any alternative vehicles, perhaps even camels and schooners, given the cost per seat. The SLS will probably fall into that territory.

      2. I don’t think TPS is really that big of an issue. The problem is TPS can slow you from hypersonic to subsonic terminal velocity by absorbing the heat of aerobraking. But it can only help you to terminal velocity, which isn’t slow enough for a safe recovery with the ground.

  2. By the time NASA gets astronauts to the Moon, they’ll be able to check into a Bigelow Hotel.

    1. The removal of toads like Shelby is probably the strongest argument against rejuvenation and life extension… “If you want a picture of the future, imagine a boot stamping on a human face—for ever.”

      And in other news, Fidel Castro and Hugo Chavez are still dead.

      1. The counter argument is, life extension might encourage people to take a longer view of things. There will always be bad guys. Too many good guys are thinking it doesn’t matter because they’ll be in Heaven soon enough, or at least safely dead, so why bother kicking against the pricks. A boot stamping on a human face forever only matters to most people if it’s their face and their personal forever.

        1. If the average lifespan doubled, I predict for a lot of people, childhood would last even longer. Why not spend decades going to school and avoiding adult responsibilities?

          1. Your scenario has the hidden assumption that life extension is uniform throughout life. But what if it was at the back end? Say you age to 70, then stay 70 until your 140? No extended childhood. Or say its at the front end? You don’t reach puberty until you’re 100. What then? Ideally you want the extedend life to be in the middle, but that’s not guaranteed.

            The other point is, doubling expectancy (which is what we really mean) is picayune and wouldn’t change much. But lets say life expectancy becomes 7,000 years or 700,000 years or 7 million years? Larry Niven predicted immortal humans would become extremely risk averse. Edgar Rice Burroughs predicted the opposite. His Barsoomians have a life expectancy of 1,000 but typically only lived to 300 or so before getting themselves killed (he also predicted a high suicide rate).

  3. So what makes SLS “comically” big, as opposed to some other pejoritive adjective? Especially when you consider it’s not all that big. The headline made me think, “The writer is an idiot.” It also made me remember when NYT referred to what would eventually become ISS as “NASA’s Space Palace,” showing an outline of the space station compared to an outline of Mir. Journalism schools produce comically ignorant graduates?

  4. As comically big and bad as SLS is, I was looking the other day at Ares V again, and I appreciated once again how much worse the NASA Frankenrocket was on track to be.

    I mean, it just kept growing and growing, because the mass load of Orion and Altair kept going up and up. It was up to 6 RS-68B’s, with some discussion of even seven; 5.5 segment SRBs, with some discussion of even going up to 6; and of course all that hydrogen needed lots of volume, so it was up to a 10 meter fairing (making all the old Shuttle tooling useless), and even greater length. The thrust of that monstrosity would have required a major rebuild of LC-39, and its size, new mobile launchers. You can easily see why the Augustine Commission concluded the thing wouldn’t be ready until the late 2020’s, even if Congress doubled the money it was throwing at Constellation.

    We still don’t know what it would have cost to develop, but if SLS is already up to $20 billion, I wouldn’t be at all surprised if Ares V had hit the $50 billion mark.

    1. Saturn V S-IC and S-II stages were ten meters in diameter. If it’d been all hydrogen (rather than the kerolox S-IC stage) it would’ve been a whole lot bigger. In any event, A six-segment solid Ares with 6 RS-68R enginers (the only kind that would have worked in this application) would not have been too big for LC-39A/B. Just too big for VAB and crawlers. Which may be stupidly big, but still not comedically big.

      1. Not so much the size or mass, but the thrust, actually: I saw some discussion in the final studies that LC-39A and B couldn’t take the kind of thrust Ares V would be putting out – not without major damage.

  5. The Pop Mech article says SLS was to fly in 2017, but it’s worse than that. The NASA authorization of 2010 that defined SLS actually says that Orion/SLS was supposed to be *operational* for Earth orbit by 2016. The first flight would have to have been in 2015 or before.

    1. Back in 2004 I pushed for a sidemount SDV with 3 RS-25 engines and 4-seg solids. It would have been ready by 2010 and could have coexisted with the Shuttle. With a side mounted upper stage derived from the Ariane 5 sustainer core, it would have enable 2-launch lunar orbit rendezvous.

      1. Right.

        No disrespect to the DIRECT guys, but a sidemount SDHLV vehicle was pretty much the only way to get a SDHLV with a reasonable development schedule and price tag. Because all you really have to develop is the sidemount vehicle, and you’ve already got the engines for it.

        You’d have to decide on it before the Shuttle supply lines all started getting wound down.

      2. That sounds similar to the many Shuttle-C concepts, which kept reappearing because they had a lot of merit compared to putting everything in the Shuttle payload bay. Another recurring idea was to use liquid fueled side boosters, but cost was problematic because it was assumed they couldn’t be recovered, except for a few winged fly-back, airport landing ideas. NASA’s still entertaining liquid side boosters as an upgrade path for SLS. But throwing away four $146 million dollar engines per launch means the SLS is a dead end, financially.

        I think the fundamental problems in all the Shuttle-derived concepts are that the external tank is too expensive, and too big an investment in labor, to throw away. The choice of liquid hydrogen for the first stage, and the desire not to throw away expensive engines on a second stage, favored a staging point that was akin to an SSTO, but with strap-ons to give it a viable payload. As a launch system, they can avoid throwing away all of it, but they can’t avoid throwing away a lot of it, until they start with a clean sheet design aimed at re-use.

        When the first Falcon 9 stage landed, it changed the landscape entirely. NASA of the 1960’s would have rethought everything based on the new tech, but modern Shelby-style NASA is going to stagger forward with yesterday’s technology and architecture, as if the program’s inertia is sufficient to put things into orbit.


        The trouble with these SLS / NASA aerospace discussions is that everybody here knows so much that we might as well hang out like Hank Hill and his neighbors, standing next to the fence, sipping on a beer, and saying “Yup. It’s crazy, ain’t it?” What can I say that everybody here can’t already write a whole book about?

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