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Hints that NASA will redo the SLS static fire test

While NASA has not yet announced any decision on whether it will redo the full static fire test of its SLS core stage — following the January 16th abort — there are hints coming from industry sources that the agency is leaning to doing another test.

According to sources at the agency, program managers are in fact leaning toward conducting a second hot-fire test in Mississippi. Due to the need to obtain more propellant at the test site, conduct minor refurbishment to the vehicle, and possibly change the erratic sensor on Engine 4, the agency estimates it will require about three to four weeks before conducting another test.

Based on that schedule, the actual Artemis 1 unmanned flight, now set for November, will likely have to be delayed one month to December, since after the static fire test it will take several months to disassembly and prep the core stage for shipment to Florida and then reassembly it and prepare it for launch. That November launch date was predicated on a successful completion of the static fire test by January.

NASA and Boeing (the lead contractor building SLS) do not have much schedule margin however. They have begun stacking the solid rocket boosters that strap-on to the core stage. Once this is done the boosters supposedly have a life span of approximately one year, which means the launch must occur by about January ’22 though I would not be surprised if NASA waives that use-by-date if it needs to.

I am in a betting mood this morning. Want to bet SpaceX’s Starship completes its first orbital flight before SLS, even though it has been in development for one tenth the time (2 years vs 20) and for one thirtieth the cost ($2 billion vs $60)? I think the odds right now are very very likely. One way or the other, the race will definitely be neck-and-neck.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

 
Unfortunately, that is exactly where that journey takes him.

 
The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.


He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

 
Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit.
 

14 comments

  • brightdark

    I’ve read that the tanks have a set number of times they can be loaded with cryogenic fuels. Is that true? If it is, they are wearing out the tank before it can be shipped to KSC.

  • Jhon

    Three to four weeks for a second test. These dopes should give up and hire Spacex to fix it. The damn thing will be in the air in a week. Spacex can change out engines in a week, these clowns need a three to four weeks to change a sensor and add some fuel. Our tax dollars at work.
    I used to love NSAS, what the hell has happened to them?

  • geoffc

    @Jhon the theory was, that the RS-25 (SSME) was well known technology. But in reality it was 1970s slightly updated technology. (New controllers, over the years, good).
    In theory the SRB’s were well known technology, but they had to be changed in size, which basically resets the experience to close to zero. (SRB additional segments require all new internal layout to tailor the thrust profile).

    The Raptor is 2010 technology and was designed to be built in large numbers, and installed fast. (If you have to install 28 on a stage, every minute counts and adds up). Amusingly Musk has said they are making changes to make engine change out even faster/simpler.

    This is not to excuse SLS’s crappy record so far. More to say, it is so badly set up that SpaceX could not fix the existing program.

    And I am with Bob. I am expecting an orbital Starship flight before SLS now. I also predict SLS flies a grand total of once for sure. Second time I am 50/50 right now. Third time I think odds are zero. (Third flight cannot be before 2025, and by then SpaceX is likely to have humans on Mars).

  • V-Man

    Of course they’re redoing the test. It has two benefits:

    1) More CYA for the various managers if something goes badly on launch day.
    2) Allows Boeing to charge more money to the program.

    A conspiracy-minded poster might even propose that they failed the test on purpose to accomplish the above.

  • Diane Wilson

    I’m not optimistic that either SLS or Starship will have a successful orbital mission in 2021. Both have some hurdles.

    SLS: 1) Get that thing off the ground. 2) Has the second stage had any flight or tests at all? 3) Anything less than recovering Orion will be a failure, considering that Orion has done this once already. 4) Isn’t this a first flight for a different service module for Orion? 5) I’d have to say that NASA management also constitutes a hurdle. 6) Any test failure can stop the whole program.

    SpaceX: 1) Heat shield for StarShip is still an unsolved problem, especially for control surfaces. 2) First booster prototype has not been built, and will need pressurization tests, just as StarShip has. 3) Thrust puck (component where engines are mounted and transfers thrust to the vehicle) is an unsolved problem. 4) Ground support equipment and procedures for fueling Starship while mounted on top of booster. 5) I expect that SpaceX will work on booster recovery before orbital flight test. 6) I expect test failures along the way, at least one for re-entry and one or more for the booster.

    Which one succeeds first? Tentatively, SpaceX.

  • Col Beausabre

    OK, is SpaceX or Spacex

  • Dick Eagleson

    Diane,

    Anent SLS:

    1) I endorse your sentiment but agree with ZimmerBob that the prospect of seeing such a thing happen in 2021 is now all but assuredly foreclosed. I had predicted elsewhere that NASA would not complete the Core Stage Green Run in Jan. and that March seemed a likelier date. I am even more certain of that now.

    2) The SLS 2nd stage is pretty much the 2nd stage of a Delta IV Heavy with a custom adapter skirt added. It, along with the SRBs, RS-25 engines and some additional more minor bits of SLS-Orion, has flight heritage.

    3) Agreed, though the “Orion” that flew some years ago was barely above the level of a boilerplate mockup. Even the Artemis 1 Orion will still lack critical subsystems, most notably its life support system.

    4) Artemis 1 will be the first outing of the European-built service module, though a lot of its pieces have flight heritage from the now-ended ATV program that resupplied the ISS for awhile. Its main engines are, like the Core Stage’s RS-25s, surplus Shuttle parts that have flown before.

    5) Agreed on NASA management being a problem, especially now that Bridenstine is gone. But he did get rid of Gerst and a number of other serial underperformers. Kathy Lueders was an astute replacement for Gerst and will, I hope, continue to do well even under whatever party hack The Usurper sees fit to install in Bridenstine’s former office. And Boeing’s management is an even bigger hurdle.

    6) Maybe not stop, but certainly delay the whole program significantly. We’re already seeing that in the case of the Jan. 16 test abort.

    Anent SH-Starship:

    1) Heat shielding for Starship is not an unsolved problem so much as a yet-to-be-fully-tested-in-flight system. We simply don’t know yet to what degree the problem is unsolved. My own opinion is that Starship’s thermal protection system (TPS) is likely to prove much less problematical than many seem to believe. The TPS tiles for the aerosurfaces and their attachment points will simply be custom shapes rather than the mass-produced hexagons to be used over most of Starship’s surface. Custom shapes will be needed for the nosecone as well. And the tiles in these areas will likely be quite a bit larger than the standard hexagons. Also, the pin-based mechanical attachment method for the tiles is much more robust than the method employed to attach Shuttle TPS tiles. In any case, even the failure of some Starship TPS tiles on early test flights is unlikely to be the main cause of any loss-of-vehicle incidents. Shuttle routinely lost tiles on its underside and had an aluminum understructure. Starship has a stainless steel understructure that can stand a lot more heat than the Shuttle’s structural innards could.

    2) Actually, most of the first booster prototypehas been built. The first two sections were mated last Nov. Now, additional sections, which had been built and set aside in the interim, are being stacked. Large pieces of a second booster prototype have recently been seen as well. The resumption of significant booster assembly activity suggests that both the so-called orbital launch platform and the upperworks of the High Bay are now far enough along to justify this renewed activity so that initial booster testing can start perhaps as early as March or April.

    3) Thrust pucks are “unsolved” in the same sense as the TPS system. The current thrust puck design for Starship has been working for awhile and a further-improved design will apparently be incorporated in all Starship prototypes starting with SN15. The initial thrust puck design for Super Heavy is also in-hand. I don’t see any showstoppers anent thrust pucks.

    4) GSE continues to be a work in progress for both Super Heavy and Starship. I don’t see any reason to suppose significant roadblocks lie ahead in GSE development. If you have some specific concerns beyond a generalized sense that “here be monsters,” I’d be interested in knowing what those might be. The recent installation of equipment to enable propellant manufacture on-site as well as all the pipes and conduits being busily laid to, and at, the orbital launch site suggest SpaceX has the GSE situation well-in-hand.

    5) I think so too. I think we might see initial hop tests of a Super Heavy prototype sometime in Spring.

    6) I think booster and re-entry test failures less likely than you do. But if any occur, I don’t expect them to impact overall program progress any more than previous testing failures have. SpaceX’s SH-Starship project is a bit like the famed Greek phalanx or Roman square infantry formations – it moves forward at all times with any casualties taken on the leading edge quickly replaced from behind.

  • Diane Wilson

    Dick,

    It’s not so much “here be monsters” as “here be surprises.” I’m well aware that SpaceX has been working on a lot of issues, like heat shields. I know that one area they are concerned about is shielding the hinge areas on flight surfaces, and they are very concerned to avoid the shuttle problem of custom tile shapes everywhere.

    The booster has a lot of rings built, but I’m really looking for integration of the build, not components. And mounting 28 engines in one shell will be a lot more interesting than the current three on Starship, or nine on Falcon. Interesting in a lot of ways – thrust, plumbing, flight control.

  • Diane Wilson noted that ” . . . mounting 28 engines in one shell will be a lot more interesting than the current three on Starship, or nine on Falcon. Interesting in a lot of ways – thrust, plumbing, flight control.”

    From the Wikipedia article (https://en.wikipedia.org/wiki/N1_(rocket) on the Russian N1 booster:

    “. . . but all of the four flown N1 Block A first stages failed because of a lack of static test firings that did not reveal plumbing issues and other adverse characteristics with the large cluster of thirty engines and its complex fuel and oxidizer feeder system.”

  • George C

    Boeing may also want to get out of this kind of contract work. Recall that Reagan started the switch to competition and fixed price with retained IP about 40 years ago for military procurement. Boeing created the 747 after losing the C5 work. So I predict SLS will launch this year to orbit. Then the thing can be honorably shut down. Boosters using both solid and liquid engines forces the operator to hire and train double with expert knowledge in two technologies. Solids use icky chemistry that is tricky to manufacture consistently. And test firing for quality control? No. Lack of in vivo testing changes how you can manage the entire effort.

  • Edward

    brightdark asked: “I’ve read that the tanks have a set number of times they can be loaded with cryogenic fuels. Is that true? If it is, they are wearing out the tank before it can be shipped to KSC.

    It is in the update in this article that Robert had linked to in an earlier post:
    https://spacepolicyonline.com/news/sls-hot-fire-shutdown-due-to-conservative-testing-parameters-not-engine-malfunction/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Spacepolicyonline+%28SpacePolicyOnline+News%29

    NASA clarified on January 21 that the core stage can be tanked 22 times. Nine of those were allocated to the Green Run test and by NASA’s count only two have been used so far. Thus, it can be tanked 20 more times. NASA is preserving 13 of those for tests once it is at KSC. So there are several that can still be used at Stennis.

    It seems unlikely that they will use all seven remaining cycles at Stennis, so NASA should have more than the 13 that they are preserving for KSC operations..

    Jhon asked: “I used to love NSAS, what the hell has happened to them?

    The difference here between SpaceX’s rapid changeout time and NASA’s not-so-timely changeouts is that Starship was designed for easy and rapid maintenance. This is necessary for rapid turnaround times. SLS is a consumable/expendable vehicle, so maintenance was not a priority.

    Diane Wilson,
    I generally agree with your itemized list, but I see a couple of items differently.

    1) SpaceX may choose to go to orbit before having a heat shield for reentry and recovery. Testing the launch portion before the reentry portion would be in line with their development philosophy. They need not test the whole system but can test various phases.

    Also: 5) That SpaceX will work on booster recovery before orbital flight test? I expect the opposite, that they will work on orbital testing before finalizing booster recovery. Unless booster recovery works out very early in the test program.

    George C wrote: “So I predict SLS will launch this year to orbit. Then the thing can be honorably shut down.

    Ah, yes. The “Spruce Goose” model of contract completion. The Hughes H-4 Hercules met its contract obligations for one flight, then was abandoned rather than find improvements — the need for it, at that time, became moot. SLS is too costly and launches too infrequently to be relied upon for regular use as a practical method of access to space.

  • Dick Eagleson

    Diane,

    Shuttle came pretty close to having no two tiles alike. Starship is in no danger of following suit, but there will be custom tiles in certain places out of geometric necessity. Starship has numerous thruster and vent ports, for example. Any of these on the windward side will have to be covered with doors which will likely require some custom tiling.

    Aerosurfaces should be able to mostly use the standard hexagons, but curved tiles will be needed on the edges and on the fairings. Each tier of tiles on the nosecone will need to be a custom shape, though all or most of the tiles in a given tier should be interchangeable.

    As noted, previously built sub-components of BN1 are once more actively being stacked. We could see the first Super Heavy prototype complete or nearly so by perhaps the end of Feb. That first prototype, though, won’t have 28 engines. It might have as few as two.

    Surprises are possible at any time. SpaceX has certainly suffered a few over the years. None has taken very long to recover from. The already high production rate of prototypes is, at least in part, one of the ways SpaceX’s development process is designed to minimize the schedule consequences of surprises.

  • Dick Eagleson: It is my understanding that in later years many shuttle tiles (on curved surfaces) were replaced with carbon-carbon blankets (I might have the term wrong), forgoing the need for individual customized tiles. Can you speak to that?

  • mkent

    I’ve read that the tanks have a set number of times they can be loaded with cryogenic fuels. Is that true? If it is, they are wearing out the tank before it can be shipped to KSC.

    Yes it’s true, but the number is high enough that it shouldn’t be an issue. The SLS core stage is only rated for 22 fill-drain cycles due to hydrogen embrittlement concerns. The Wet Dress Rehearsal and initial Static Fire have used two of them.

    NASA would like to reserve 13 cycles to be used at the Kennedy Space Center — one for a wet dress rehearsal at KSC and twelve to be used in launch attempts. That leaves nine available for the Green Run. With two gone, NASA still has seven more cycles to use before they have to re-evaluate their allocation.

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