What Was Old Is New Again

Whoever had the brilliant idea of building a rocket out of 1970s technology apparently was unaware, or had amnesia about all the problems caused by hydrogen with the Shuttle.

[Thursday-afternoon update]

Of hydrogen and humility:

“I would simply say to you that space is hard,” he said at an August 27 briefing when asked what lessons NASA could take from the extended delays in SLS’s development. “We are developing new systems and new technologies, and it takes money and it takes time.”

Yes, space is hard. It’s even harder when you make terrible design choices in order to provide a jobs program for existing workers and contractors. There is little new about either these systems or technologies.


54 thoughts on “What Was Old Is New Again”

  1. The pork checks cash fine no matter what happens. Once again, we see the biggest problem with publicly funded projects – a huge indifference to getting things done.

      1. The question is whether or not it had hydrogen-leak based scrubs. As to other scrubs, my personal memory says the Buran launch had one scrub, when the crew access arm refused to retract at t-51 sec. I don’t know as much about the Polyus launch. In video of the launch, you can see it wobble to the left on liftoff, then straighten out. Then reports are the Polyus stage, rotated 180deg before ignition and put the payload in the drink due to a programming error. STS, SLS, and Energiya are comparable in scale. The other ground-lit hydrogen stages I can think of are Ariane 5, H-II, CZ-5, and Delta IV (a.k.a, “hydrogen fireball”). It’d be interesting to look into them, even though they’re significantly smaller.

        1. and Delta IV (a.k.a, “hydrogen fireball”)
          Fireball DIV-H. I like the Delta India Victor Hotel because it’s so similar to how I like my steaks. Browned on the outside with a warm red center…

        2. A quick check shows Ariane 5 put a battleship stage on the actual launch pad and spent 3 years working out GSE isses, H-II variants did the same. Probably SOP when there’s budget.

          1. Yeah, too bad SLS was so underfunded and under such schedule pressure that they never had the opportunity to do such necessary tests. /s

  2. To paraphrase Orwell, the spacecraft build is not to be achieved, it is continuous.

    IOW, NASA will have far, far less to do, fewer people, less budget if they are successful…..NASA is basically the script for The Producers.

    1. NASA isn’t just risk averse, they are even more frightened of success. A quarter million people got laid off when Apollo _succeeded_.

      1. Even though all the people that were traumatized by that are long gone from NASA, the institutional memory remains:

        Researchers hung a bunch of bananas up a pole inside a cage with 3 monkeys. When one monkey climbed the pole to reach the bananas, a firehose was used to soak all the monkeys. The monkey scurried down the pole without one banana.
        The next monkey climbed the pole to get the bananas and they all got the same ice-water bath. The third monkey went for the bananas and the others beat him up. This continued dozens of times with all three monkeys until they finally gave up. They no longer tried to reach the bananas.
        The researchers replaced one of the monkeys with a new monkey. When that monkey spotted the bananas, he started climbing the pole only to be thrashed by the others. They would not let him go up, fearing another cold shower.
        Another new monkey was brought into the cage. He tried climbing the pole but, again, only to be pulled back down by the others.
        Eventually, there were no more original monkeys in the cage. They had all been replaced, and yet none of them dared climb for the bananas. They never experienced the ice water but they feared impending danger and thus never let any others reach for the bananas.
        I got the ice water at Otrona and ISI and OSI (failed optical disc companies in the mid-80s), Hummingbird Launch, Vela Tech, Rotary Rocket, XCOR, and Deep Space Industries. 40 freaking years of ice water and beatings until morale improves. But I won’t block anyone else from trying, if Elon grabs that damn banana, more power to him. But there’s another banana over here that doesn’t seem to be guarded…

        1. I’ve had a few cold beatings. I’m trying for an unguarded banana and starting a second company to pick it. Hopefully getting several bunches. Would you believe it’s based on a hardware/business concept of mine?

  3. Just out of curiosity, with such tight limits around hydrogen leakage and flammability limits around the pad is the plan still to deliver crew *after* the rocket is fueled?

    Because after all isn’t that they way it’s done?

    1. That’s the way they did it with all their manned programs including the Shuttle, so odds are they’ll plan on doing the same with Orion. It seems they’d have some hesitation about approaching the SLS stack if the leaks aren’t fixed out of risk of recreating the Hindenburg.

    2. NASA pushed back against SpaceX’ crew-then-load plan, but it makes sure the crw can punch out on the abort system if anything goes wrong, and the white room team is not exposed to the hazard of a fueled launcher. NASA will never admit that they’ve had it ass-backwards for more than half a century, and Artemis 2 (if it ever happens) will put a dozen people on foot next to a leaky fueled vehicle.

        1. 2 1/2 hours for Shuttle. Eight for a big ol’ stage [SLS]

          But remember, it’s important that crew be launched on the biggest rocket ever, because, reasons.

          Even Mike Griffin wasn’t a proponent of that idea. Trying to abort an Orion parachuting through a debris field of burning solid propellant however…


          The propellant loading process, which took about two and a half hours for the shuttle, will take eight hours for the SLS despite its use of shuttle-heritage hardware. “That’s for a couple of reasons. First, it’s a big ol’ stage,” Blackwell-Thompson said. A second reason is that the SLS has an upper stage that must also be fueled, requiring personnel to stagger the loading of the two stages.

          1. But remember, it’s important that crew be launched on the biggest rocket ever, because, reasons.

            Well, one day, before long, they will be, when Starship is ready for its first crew flight!

            But only because it actually makes sense for the architecture and what it’s intended to achieve.

    3. I don’t know about “tight” limits – the limit seems to be 4%, which apparently is explosive.

      The problem is that it doesn’t take much to be explosive in air.

      1. You’d be hard pressed to come up with a fuel that is flammable over a wider range of air / fuel ratios than hydrogen, which doesn’t really want to hang around in the diatomic state if it can avoid it.

        Ethylene Oxide (which by name alone, doesn’t sound that stable) has hydrogen beat, but not sure how good a rocket fuel it’d make.


      2. From a recent project, so it’s at the top of my mind, the explosive limit for hydrogen is between 4 and 75%. One of the issues is that hydrogen is so light compared to air that in an an enclosed space like a room, an explosive concentration may occur near the ceiling from a relatively small amount of gas. This wouldn’t be a problem in the open but hydrogen detectors generally alarm at 2% to allow warning before a dangerous situation exists.

        1. I have a feeling that basement level garages are about to become a thing of the past in California after 2035.

        2. Wasn’t one of the concerns at Vandy with the AF Shuttle Launch Facility hydrogen build-up in the enclosed flame ducts for the pad that we’re ready-used from the previous Titan pad?

  4. I just wonder if it’ll be hilarious, a disaster, or just sad when this thing reaches end-of-life on the structure and/or solids without ever launching.

    We’ve had lots of rockets expended after one launch, and a few expended after many, but how many rockets have seen expended after zero launches?

      1. I would say that SpaceX would be figuring out how to retrieve re-use the 16,000 pound launch escape system, but they wouldn’t have added it in the first place.

        1. Especially when it adds in its’ own failure modes. Not to mention driving up the required performance of the vehicle necessary to launch.. Thus necessitating more size and tighter margins… Which leads to ………..

          1. I calculated that 16,000 lbs would be the weight of a steel plate 16.5 feet in diameter (the base of the Orion) and 1.84 inches thick. That’s thicker than the frontal armor on an M4 Sherman tank. That’s thicker than any piece of armor ever put on a combat aircraft, including the A-10’s titanium bathtub.

    1. AIUI, the SRBs have already reached the max time elapsed since stacking, but NASA and/or Space Force keeps issuing waivers. Ditto the battery for the FTS, which has a 20-day lifespan, but they’d already granted one waiver to make yesterday’s window. Of course, now that it’s going back to the VAB again they can service that, as well as the batteries on the ride-along sats.

      1. If they decide to go for an October launch window, it was Arizona CJ in an earlier thread, that reported here that the SRBs are wavered until December. Considering the stacking started Jan 7 2021 <- (21 notice), we are waiving a waiver. If the launch is deferred past October, I'd expect a transport back to the VAB for a re-stacking. This I wouldn't yelp about at all. I mean a whole year past the original expiry date, this ought to be done, if for no other reason than to gather *actual* data on prop sag and J joint issues. This might actually be more useful data at this point than what you'd get from actually launching the current SRBs.

        In retrospect (and admittedly this is Monday morning QB'ing) the SLS stack should have had more wet dress rehearsals maybe with dummy mass equivalent SRBs if that is necessary for structural stability.

        If this is some kind of race against Starship/Super-Heavy, then that motivation is not any better than the Challenger accident processes. Like the idea floated at the time that it was the Reagan Administration pressuring NASA to get a teacher in space in time for the SOTUS, I'm going to dismiss that thinking out of hand.

  5. My wife worked at Rocketdyne in the late 80’s through late 90’s, and knew a lot of the SSME engineers. According to them, every time they went to the Cape to support a Shuttle launch, they brought two turbopump assemblies with them, and always had to swap out at least one. So much for “legacy hardware.”

  6. In retrospect, perhaps it would’ve been better to fuel through four four-inch pipes instead of one eight-inch pipe, on the assumption that two or three of the quick disconnects will probably seal properly, which would be enough to get the stage fueled up.

  7. Don’t worry, it’s not really as if they’ve spent tens of billions re-creating all the problems of the Shuttle program.

    NASA, in true NASA fashion, has gone above and beyond! With SLS, Shuttle issues that caould cause extensive delays and risk have not been re-created, they’ve been magnified. Shuttle had the rotating service structure, allowing some things to be serviced on the pad. SLS, well, you’ve got to roll it back to the VAB to change the FTS battery, or a sensor, or… pretty much anything.

    With SLS, as Rand pointed out long ago, there are a plethora of ticking clocks once the vehicle is even close to the pad, on a vehicle far more problematic to get through a countdown.

    1. Any component can filibuster the launch.

      There’s probably a better joke that can be wrung out of that.

      1. Using the development baseline of the system makes full use of the cloture rules of rocketry aka “launch on waiver”.

  8. My concern about NASA is they don’t seem to work towards any of my priorities. MAYBE (and I do so hope) the military Space Force is working part one. “Everything old” might imply the Reagan-era SDI technology, but if so the work is happening, er, “under the radar”.

    I made this comment on Instapundit but I repeat myself here.

    My personal priorities for “space”:

    a) Detection and deflection of incoming masses — natural meteors, military missiles, or de-orbiting satellites. Nobody needs a chunky chunk of burning junk dropping onto a city. Reagan’s SDI should be just the beginning. This STARTS with replacing the Arecibo observatory on Earth, then augmenting it with a space-based “telescope”.

    b) Deflection of natural masses should, when economically feasible, park the mass in a convenient nearby orbit for later. “Later” being somewhat ambiguous. If the space-deniers are more correct, then these parked rocks get used a century or so after the Antarctic and ocean floor minerals seem depleted. If the space-fans are more correct, the parked rocks almost immediately obviate the need to mine (plunder) any more minerals from Mother-Earth’s surface. Either time table works for me.

    c) Discover new resources. 15th century Europeans ventured into their “new world” for gold, but the really important resources were sugar cane, maize/corn, tobacco, chocolate, beaver pelt, tomatoes, potatoes … stuff the Europeans didn’t know they needed until they found it. “Prediction is very difficult, especially about the future.” But there are valuable physical things, and valuable locations, out there just waiting for us to accidentally trip over, and exploit. The sooner the better.

    d) Disperse. The population, the economy, anything that can be moved and grown and operated in more than one place, should be. As much as we’ve made of the eggs in our present one basket, we KNOW that two baskets are better just in the (long-term inevitable) case of accident. Or theft or attack or political mistake.

    Detect, deflect, discover, and disperse.

  9. Speaking of what’s old is new again, I was reading about the test firings of the RD-171MV engine, now to be fuelled with naphthyl, and thought, instead of taking the engine out of mothballs, they’re putting mothballs in the engine… (I’ll show myself out now.)

  10. The Shuttle is an example of a project where a decision made early ends up driving it. For the shuttle, it was the decision to place the main engines on the orbiter. That meant that every Joule that considerable dead, once the fuel was expended, weight represented in orbit in terms of kinetic and potential energy had to be dissipated by aerobraking on the decent.

    That required that those engines be the most efficient in terms of weight that they could devise without reference to usability or cost. This, unsurprisingly, lead to those other desirable characteristics being driven to the extreme limit of tolerance, arguably beyond.

    Then there’s the decision to pair the most efficient engines ever built with what almost have to be some of the least efficient in the name of reusability. Instead of using several SRB’s of manageable size, the asymmetric configuration driven by the location of the main engines meant that only two SRB’s could be used.

    Of course for SLS, none of these considerations apply. The only real justification is a gigantic case of the sunk cost fallacy to “use” these left over components in the name of economy, no matter what it costs.

    1. In the MIT Open Courseware on the development of the Space Shuttle, they brought in all the top people to give a lecture. In one, it was mentioned that someone floated the idea of putting the SSME’s under the external tank, and then moving them over to the Shuttle before the tank was jettisoned. Someone derisively implied that the engines would rotate over, and I imagined an axis aligned from nose to tail about which this rotation would occur. If anything went wrong during the rotation, it would be total loss because there would be engines and piping hanging beneath the Shuttle during re-entry.

      I immediately thought that a simple flap would’ve worked. If you picture the Shuttle horizontally, atop the ET, draw a diagonal line from the back of the shuttle toward the bottom of the ET, marking the flap position. Add rear-facing engines and make some structure on the back of the ET that mates to the flap, to transfer the thrust from the SSME’s directly to the bottom of the tank. You can have the flap spring loaded to swing back up into re-entry position, and have it just snagged onto the ET and held there with a couple of explosive bolts, mitigating the risk of anything going wrong with retraction.

      But in an alternate universe, Elon Musk travels back in time to make Raptor engines (perhaps hydrogen fueled ones). Those are about $1 million a piece now, and in 1980 dollars that would be $278,000. Put them on the bottom of the ET and simply throw them away. Each RS-25 initially cost something like $40 million, so you’d have to re-use them 143 times before the huge initial cost starts saving relative to expendable LH2 Raptors. But each RS-25 had to be torn down, inspected, and test fired, and that probably cost way more than $278K.

      Of course if you continue that train of thought, you think of maybe using methane instead of LH2, with perhaps two-stages. And maybe use methalox and Raptors to replace the SRB’s. And hey methalox doesn’t need foam insulation. Pretty soon you have some kind of two-stage Super Booster with a glider strapped to the side. Then you just put tiles on the upper stage and throw the glider away.

      And so here we are.

      1. Then you just put tiles on the upper stage and throw the glider away.

        You don’t need fancy tiles, if your upper stage is fluffy enough.

        1. You don’t need fancy tiles, if your upper stage is fluffy enough.

          Coming in from a Moon or Martian, TEI trajectory this way reminds me of a song:

          Skip, skip skip to the loo[u],
          Skip, skip, skip to the loo,
          Hold your barf bag close as we go,
          Through another 5g slow,
          Down and up and down we go,
          Skip to the loo my darling!

  11. I’ve become convinced that the best case scenario is a high-profile catastrophic failure that kills the program before they get around to putting humans on this monstrosity.

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