50 thoughts on “SLS”

  2. “What is the point of ten thousand engineers devoting lifetimes to developing deep insight into the workings of the universe if these, the cream of the cream who run space flight at NASA, cannot be trusted to know what’s wrong and what’s right. ”

    Being smart doesn’t mean you are a good person, often the opposite.

    Very detailed essay and it presents the problems with SLS comprehensively while people usually just focus on one aspect or another.

  4. Pingback: Long March 9 | Transterrestrial Musings

  5. Much the same things could be said of the rush to “renewable” energy based on the CO2 – climate change conjecture.

  6. Man. This is just *savage*. Brutal. And by “brutal,” I don’t just mean brutal on Congress, but also on NASA itself.

    And hard to disagree with.

    I’m amused reading through the responses over at the Space Launch System subreddit this evening. A surprising number (and not just the drive-by SpaceX fanboys) are willing to admit that there’s some justice to Casey’s observations.

    The case for SLS was pretty tenuous in 2011, though maybe you could at least understand, sorta (if not agree with) some of the skepticism about using available or soon to be available commercial launchers via distributed launch. But ten years later, in 2021, it really is reduced solely to pork.

    Maybe you should sticky a link to Casey’s piece on the sidebar, Rand? It might be the best one-stop shopping takedown on SLS that has been published.

    1. “The case for SLS was pretty tenuous in 2011, though maybe you could at least understand, sorta (if not agree with) some of the skepticism about using available or soon to be available commercial launchers via distributed launch. But ten years later, in 2021, it really is reduced solely to pork.”

      The case for SLS as the primary launch vehicle is long gone and now the case for SLS as redundancy has also slipped away.

      SuperHeavy/Starship had an accident? Is it something that can’t be fixed in the next couple months on any of the hundred of them sitting around?

      I suspect ULA and BO will be using the redundancy card to get government contracts.

      1. Yeah, I was only halfway through when I posted that.

        But in the meanwhile it looks like all the references to you triggered someone with a terminal case of Rand Derangement Syndrome down in the combox. Where do these people come from?

  8. Sad rehashing all that. But as Santayana* said….

    *George Santayana (1905) Reason in Common Sense, p. 284, volume 1 of The Life of Reason

    1. *”Man it’s a hot one
      Like seven inches from the midday sun
      Well I hear you whisper and the words melt everyone
      But you stay so cold
      My muñequita
      My Spanish Harlem Mona Lisa
      You’re my reason for reason
      The step in my groove, yeah”

  9. Sorry for hijacking a thread but saw this . Figure it related another pig of a government program. Shouldn’t they be filling the low mix with armed drones at this point? Not looking for a another toy for the officer core to fly in.

    1. Bear in mind that it is David Axe “reporting”. Was the F-35 ever supposed to be the “low end” of the mix? It was sold as having a variety of capabilities but low end is a loaded term. How many F-35 pilots call it a failure of a plane? All the doom and gloom was great when the F-35 was in development but now there are planes out there flying to judge the program on.

      The AF just announced their new light attack plane, https://www.thedrive.com/the-war-zone/39302/the-air-force-finally-has-its-first-new-at-6e-wolverine-light-attack-aircraft

      Trump lit a fire and the AF developed their next gen fighter plane in about a year, https://www.defensenews.com/breaking-news/2020/09/15/the-us-air-force-has-built-and-flown-a-mysterious-full-scale-prototype-of-its-future-fighter-jet/

      Axe notes that the AF wants something like the F-15 and F-16. Maybe the link above is what he is alluding to as the replacement.

      1. There are a couple of routes I would pursue.

        One is to make the F-35 a higher-end aircraft by turning it into a twin. Drop the vertical landing requirement, keep everything from the lift-fan forward as is, for the most part, and just change it from there back to be like an regular twin engine fighter, with the space between the engines devoted to internal stores and fuel.

        Another thought toward the same basic goal was to revisit the F-22 program, and either go with a pair of the wildly expensive F-135 engine, or instead use two pairs of F-404’s or F-414’s, which would give a flatter profile, more room for stealthy engine ducting (as the F-414 is 5 1/2 feet shorter than the F-135) and more thrust for far less cost. But the aircraft would still need all the fancy tech that was put into the F-35.

  10. His description of the green run test reminds me of the Orion Pad Abort One test. It too was an admittance test, but it was “successful” in that it looked like it was supposed to look. It just didn’t test the flight design it was created to test.

    That was over a decade ago.

    1. *sigh* thanks for the reminder. It’s like having a test to see if you can capture a space capsule in a net, only to have the capsule miss net by a mile. Then running over to the crash site where the capsule lays in pieces, throwing the capture net over it and calling it a day.

  11. In 1986 there were still enough Apollo veterans floating around that, had anyone involved had the courage to declare Shuttle a total loss and permanently ground it, there is every chance that a rocket in the style of the Falcon 9 could have been human rated and operational by 1990, representing a genuine path to steady improvements in reusability and cost, and a commitment to fact-based reality as the program’s guiding star.

    I wish I could agree with this argument but alas, I’m afraid it is a non-sequitur (the result does not follow from the premise). Yes I agree, had the Apollo group as a whole stood up in 1987 and declared the Shuttle unsafe to fly, there is no way Shuttle flights would have resumed. It would have been politically untenable. But it does not follow that a reusable Falcon 9 like vehicle would have been the result. Probably just the opposite. I suspect we would have gotten the Ares architecture two decades earlier. (Although hopefully not the ‘Liberty’ stick and thanks to the o-ring debacle probably not). Most “experts” would at the time have gladly tossed the idea of the reusable rocket in the dust bin.

    1. Most “experts” would at the time have gladly tossed the idea of the reusable rocket in the dust bin.

      And given the technology of 1987, even then, maybe rightfully so!

      1. My wife and I have each, separately, worked on at least a half dozen government “flyback booster programs” (USAF or NASA) over the years. Not one of them ever got past what today would be called the “risk reduction phase,” an in-depth analysis, modeling, and general hand-wringing exercise designed to eliminate any and all problems before design was even begun. Elon got past that part by designing, building and testing hardware that might or might not work (i.e., he took risks, rather than try to “reduce” them by just thinking real hard), and learned from success and failure alike. The government would never do anything like that, because failure is not an option. Better to never do anything whatsoever than to try something and fail.

    2. At the risk of thread hijack. Another of the paths not taken with Shuttle post Challenger, was satellite retrieval. If memory serves, we had one or two examples of that pre-Challenger, even the one launch of a satellite from the cargo bay with a liquid fueled upper stage, also pre-Challenger. All banned post-Challenger and were never repeated. Satellite retrieval is a technology we had for a very brief period and then lost. Is there a business case for it now that reusable rocket technology has crossed a threshold?

      3. There were several satellites launched from the Shuttle, both pre and post Challenger. None of them used liquid upper stages. NASA and/or the Air Force was working on a Shuttle version of the Centaur upper stage but the astronauts opposed its because they deemed it too dangerous. IMO, they were right. A fully fueled Centaur in the cargo bay is basically a big bomb. What could possibly go wrong?

        Satellites launched from the Shuttle used one of two techniques. One was to attach them to an Inertial Upper Stage (IUS), a two-stage system to deliver payloads all the way to GEO. That was used on several missions, mostly military or government satellites that needed delivery straight to GEO. These included DSCS-IIIs (two launched together in 1985), DSP, and TDRSS. For satellites that could circularize themselves from GTO to GEO, they were launched with a Payload Assist Module (PAM) that placed them into GTO. There were a couple of them that failed to fire, so they were retrieved on a later mission, fixed, and reflown. There was at least one other satellite retrieved from orbit, the Long Duration Exposure Facility (LDEF) that was launched pre-Columbia and recovered post-Columbia. There may be another example but I’m too lazy right now to look for it.

    3. (Although hopefully not the ‘Liberty’ stick and thanks to the o-ring debacle probably not).

      Precursor rockets that might have been used in an Ares I like-architecture that either were in existence or about to be at that time were the Titan IV and Atlas 5. The longest pole in the tent would be moving either to a capsule or potentially a lifting body design to place atop either of these after a “man-rating”. Here, grab onto this end of the goal post.

    4. But it does not follow that a reusable Falcon 9 like vehicle would have been the result. Probably just the opposite. I suspect we would have gotten the Ares architecture two decades earlier.

      Alas, all too probable.

      And even if we were lucky enough to pull off a clean sheet departure from STS architecture, it seems a safe bet that whatever NASA did procure would have been expendable – perhaps with something like VentureStar bouncing around in development hell on the side.

      Still, even an expendable liquid rocket with a capsule or lifting body on top was pretty sure to be safer than the Shuttle.

      1. I also suspect the idea of reusability, if left alive, would have focused primarily on what returns in the Shuttle reboot. Thus reuse would have focused solely on the capsule or lifting body not the LV. At least for a decade or more.

        1. And then there is the issue of what becomes of the heavy lift requirement. In the Bozo-bin of historical speculation, I suspect we might have seen not an Ares V predecessor, but rather, in the world of ‘cost’ semi-consciousness of the times, moving up of the Shuttle-C concept. What with two orbiters in hand, and one nearly built, it would have been extremely difficult for NASA to just walk away. Also remember, the AF had made a big bet on Shuttle at that point in time. Removing humans and their life support for automation that could land and possibly safely abort a cargo Shuttle might have rescued the Vandenberg launch facility and would have kept space station goals on-track. Shifting the focus of Shuttle to strictly heavy lift cargo only, might have obviated the need for building a fifth shuttle altogether (sorry Endeavour). And the three heavy lift cargo variants of Columbia, Atlantis and Discovery would have kept us going until an expendable HLV appeared in the mid to late 90s to retire this very expensive option. Esp. if we were to lose another cargo variant to an accident. Seems like the path likely taken to me.

        2. Something that gets forgotten when harking back to the Shuttle idea is the stage and a half S1C, which dropped the F1s for parachute and air recovery and expended the tankage and one engine and supposedly could put 50,000lbs in LEO. Your choice of capsule, spaceplane, or the rest of a Saturn V stack if you were still going to the moon or orbiting a monolithic space station.

  12. First, my obligatory point that an expendable SuperHeavy/Starship (a.k.a. Starkicker) should be able to put at least 100 metric tons through TLI.

    Second, we don’t know when or even if the first-generation Starship will lift off manned. As some of us have noted in earlier discussions, it’s not impossible to equip a LEO passenger Starship with a launch escape system (at the cost of about half the payload, but 50 metric tons of people is stll quite a few). Then you could launch the BEO Starship empty, refuel it, and only then rendezvous with a LEO passanger ship and put the crew aboard.

    Third, anybody flying on the first couple of hundred Starships to Mars will have made peace with their Dear and Fluffy Lord already. I’d volunteer even if I had to ride through liftoff on the first crewed flight. I’m 70. What have I got to lose? Saying I’m 80? Seems like a good deal to me!

    1. I’d volunteer even if I had to ride through liftoff on the first crewed flight. I’m 70. What have I got to lose? Saying I’m 80? Seems like a good deal to me!

      I can’t argue against the best kind of logic. Well said.

      1. I would make the case that space is for the young, specifically all the young SJW’s on Twitter. What if we just launched them all into deep space, perhaps towards Alpha Centauri?

  13. Of the several ways (that are obvious to me, anyway) to include a launch (and EDL!) escape system on a LEO passenger Starship, my favorite is to replace the cargo “fairing” with a passenger compartment built into a semi-ballistic “lifting body” the same physical size and weight as a full cargo Starship. It would eject off the propulsion section using methalox thrusters derived from the lunar landing engines under development (fed from speculatively located fuel and oxydizer tanks). It would carry off the forward flaps and heat shielding, maybe have some added abalative heat shielding here and there, and would need a supersonic ballute and landing parachute to soften the final impact wherever you came down (I aim for ISS but sometimes hit London?). My guess is, the all added hoo-hahs would weigh about 50 metric tons. With airline style seating, you could still get a hundred-plus people aboard. And, like that, you also got a sketch for a P2P passenger Starship. I don’t actually like flying on deathtrap airliners, no matter how unlikely the failure scenarios. Dying on impact with Mars is one thing. Dying on the way to Diseyland is quite another (and there are designs for zero/zero ejection cabins for airliners; the alternative we all face is death by beancounter).

    1. I was thinking of just rigging the Starship interior to hold a Dragon V2 capsule more or less intact. Eject in an emergency and power descent and / or parachute down. Inelegant, can only hold 7, but maybe a quick way to a technology demonstrator?

    2. Coming up with ways to survive a botched flip is easier than a launch abort scenario.

      Assuming the Starship can always establish a controlled free-fall, its terminal velocity seems to be about 67 m/sec or so. That’s not a lot, so if you used all 9 meters of its diameter (minus 4 feet on either end for structure) as a crumple zone with uniform acceleration, the passengers would decel at 30 G’s. Musk has talked about making an 18 meter diameter follow-on, which would drop the decel to about 14 G’s. But you have to have the interior layout pretty much dedicated to being a controlled crumple zone.

      If they had a pressure-fed methalox Super Draco system, they could have a highly reliable horizontal touch-down mode, but then if they went that route, they’d get rid of the flip because it would just increase the probability of failure.

      A detachable passenger abort cabin that can handle all the Crew Dragon abort scenarios seems like the only way to really have a fully workable abort system, but that seems like a bigger development project than Starship itself.

      1. I don’t think so. For one thing, it wouldn’t have to be so rigorusly tested (unless you thought the failure rate would be so high its unlikely Starship itself would work out financially). It’d be just like the Dragon 2 Superdraco abort tests: fire a boilerplate off a test stand to simulate pad abort. Sacrifice an EOL SuperHeavy to test ascent abort, then load one into orbit and abort during the worst part of EDL. If it came down it one piece, it’s good enough, giving you “some chance of survival” as opposed to “certain death.” At high flight rates, you’re going to lose a few passenger ships. By then it’ll be no worse than the typical airliner crash.

        1. Some of the ways to make a separable crew abort section run into a cascade of increasing problems, where the implementation of a seemingly simple idea keeps creating issues that need a lot of engineering and added complexity to solve. Almost the entire Space Shuttle suffered from that effect, where they kept having to add more and more systems to make a simple feature work.

          You have to move the header tank out of the separable passenger section, otherwise you’ve got a giant (and still full) cryotank in the middle of the passengers, and a large fuel-disconnect, possibly in the middle of the heat shield, so the nose can separate from the rest of the rocket. Relocating the header tank changes Starship’s overall CG, which will require further design modifications.

          If you separate the forward section of Starship, you’ve got an added set of separation points. If it separates with the forward flaperons, you’ve probably added some serious re-entry CG issues, and the simple flaperons need to become a set, which means you’re designing another controlled re-entry vehicle that has to double as a part of the normal re-entry vehicle.

          But if you don’t keep the forward flaperons, you’ve got a capsule that re-enters bottom first. If it comes in bottom first, you need an ablator on its base. You also quite likely need to add TPS all around the vehicle, instead of just having TPS on Starship’s bottom side.

          You’d want the abort vehicle as small as possible, to reduce the weight, and thus reduce the required amount of stored abort propellant, COPV tanks, etc. But that means you’d want hatches (that can survive re-entry heating) between the abort section and the rest of the pressurized nose section. That likely means you need to have hatches in the heat shield.

          But then the rest of the pressurized nose needs to have it’s on forward bulkhead, because otherwise you’d have to rely on a massive number of perimeter bolts (all explosive) and seals around the perimeter between the escape capsule and the main crew area.

          But for aerodynamic stability when aborting at max-Q, you might require an aerodynamic trunk for the escape section, similar to Dragon, and that trunk would’ve been around the large pressurized volume behind the escape section, or it would be the pressurized section, in which case you’ve added another major separation point.

          And you need to add a thermally protected, detachable cover for a parachute system. And you need to add multiple parachutes of a size possibly never attempted before. And NASA will want you to test those multiple times.

          And as Rand might ask, at one point are you just adding more and more ways for a catastrophic failure to creep in, while ballooning the cost and adding years to the development schedule? And then if someone finds a vastly more elegant abort system concept halfway through an expensive development program, would they change course or just keep forging ahead?

          1. I think the existing Starships are a ways away from holding a crew. I expect even more drastic changes to Starship over time than what we saw with Falcon 9.

          2. You can always nitpick an idea to death, making it perfect instead of good enough. The scale of redesign to make this work would not be as large as all that, and, with the SpaceX design and testing algorithm, it’s not going to cost a lot, and it’s not going to take long before, having done the heavy lifting in CAD, you build one, fly it to 10km, and see what happens. If it floated down in one piece under its parachute, then you’d start the high altitude and orbital testing. The point would be to keep it as simple as possible, knowing that even just putting in a crew cabin will change the CG. The landing header tank is in the nose because cargo and tanker starships will go through EDL empty. I suspect SpaceX already knows crewed Starships will be not be coming down empty. That’s going to make a difference anyway you look at it.

    3. Dying on the way to Diseyland is quite another

      Yes, and certainly Disney is not looking for competition with the Space Mountain experience. Even if there are no repeat customers

  14. I’ve always wondered why they didn’t just brush off the Shuttle-C plans. If it was true what they claimed – they wanted shuttle-derived heavy-lift, then shuttle-C would have been the route IMHO, and could have put well over 100T (some claimed up to 170T) in LEO. Not porktastic enough, I guess.

    They said the big drawback with Shuttle-C was the need to throw away 2 SSME every flight. (Odd, isn’t it, that SLS throwing away 4 is okay?). Shuttle-C was considering going with the RS-68 engines instead, as they are cheaper.

    Shuttle-C would have been, IMHO, an expensive kludge – though vastly superior to SLS.

    1. There was a design for a Shuttle SDV that was better than C from 1977. SRB and ET, with a thrust frame on the side and a recoverable (by heat shield, parachutes and airbags) boat tail with 3 engines on the bottom and a cargo box of whatever or an upper stage inside the frame. I did a little article for Spaceflight back in 2004 based on this, showing how you could repurpose an Ariane V core as an upper stage and get a 2-launch (crew on one, lander on the other) lunar capability for not very much.

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