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Monday, August 29, 2022

Artemis Didn't Launch - Was This a Management Screwup?

As most everyone knows, the Artemis I mission never got out closer than T-40 minutes to launch today when a problem with engine chilling arose that affected only engine 3.  Pre-chilling isn't to reach cryogenic temperatures, although the chilling is done by running some of the liquid hydrogen fuel through the fuel tubing of the engine.  They chill the engine until the sensors (wherever they are) reach a temperature of about 40 F (5 C).  (See note at bottom)

All that aside, the issue that aborted the count being tracked to engine 3 has led some to remind us that engine 3 wasn't properly tested during June's Wet Dress Rehearsals.  Early in the day, the Mail (UK) said,

Monday's disappointment is due to a leak in engine 3 that was not detected in the last wet dress rehearsal due to testing being cut short because of a separate hydrogen leak.

Later in the day Ars Technica offered considerably more details:

Beginning in April of this year, NASA conducted four separate "wet dress rehearsal" tests during which the agency aimed to fully fuel the SLS rocket and countdown to T-10 seconds, ending the test before ignition of the main engines. Each of these four tests ultimately ended prematurely, although the fourth attempt in June saw engineers bring the rocket down to T-29 seconds.

However, to reach that late stage in the countdown, NASA had to "fool" the flight computer. During the test, a 4-inch hydrogen line—smaller than the problematic 8-inch line on Monday—had a leaky seal. To complete the wet dress test, NASA chose to mask the leak from the ground launch sequencer, the ground-side computer that controls the majority of the countdown.

Because of this masking, NASA could not complete the engine chill portion of the test. Had it done so, the agency may well have uncovered the problem that caused a scrub on Monday. In hindsight, therefore, NASA probably should have completed a full wet dress rehearsal before rolling the rocket out for a launch. Instead, the agency effectively attempted a fifth wet dress test on Monday, when the world was expecting a launch.

Now bear in mind that engine 3 chilled properly and was tested thoroughly during the Green Run full duration engine fire in March of '21.  It doesn't seem completely unreasonable to say that since it worked then it should have worked in June and "something else" was what kept the June WDR test from succeeding.  The problem with that line of thought is that one reason for doing these tests more than once is that the vehicle is being handled a lot between tests and something could have gotten broken.  

Then there are things being mentioned that kind of creep me out.  Like the fact that when the fueling operations began (two hours later that they should have started, due to thunderstorms in the area overnight) NASA had to do what I call Universal Software Fix to the SLS. Seriously.

...work to fill the large liquid hydrogen tank was stymied by a leak at an 8-inch inlet leading into the tank. This problem was ultimately resolved by stopping the process and then restarting propellant loading—yes, NASA resolved the problem by essentially turning off the SLS and turning it back on again.

I had hopes from reading the NASA Artemis blogs that we might have some more details from them this evening, but no joy.  Earlier in the day, I saw an unconfirmed report that engine 3 was leaking in some unusual way - and no details beyond that.  If the engine itself checks out in whatever data they have and examinations they can do, it's possible that they could target the next launch window on Friday afternoon at 12:48pm ET.  If engine 3 needs to be replaced, the vehicle needs to be rolled back to the VAB.  Given how long it took to do that after the June WDR, and looking at the launch windows for the rest of September and October, it looks like launching by the first week of October doesn't seem likely.  If they're not back at pad 39 and ready to countdown to a September 28 liftoff, it looks like their next good window is in the last two weeks of October.

Engine 3 (highlighted at upper right and described below that) is the second most flown of the four engines, flying six Space Shuttle missions.  Of course, these reusable engines will all be thrown into the Atlantic after the booster Core does its job.  NASA Graphic.  The similarity between the SLS and Shuttle hardware gave rise to the idea that SLS stands for “the Shuttles' Leftover Shit.”

EDIT 8/31/22 2150 EDT:  Added strike through of a couple of sentences in the first paragraph.  An error or typo in a source I used resulted in the wrong temperature for the chilled engines.  See the post dated today, August 31.  



15 comments:

  1. HAH! I never heard that translation of the SLS acronym!

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  2. "Of course, these reusable engines will all be thrown into the Atlantic after the booster Core does its job. "

    That statement made me pause and think, Hold it, they do what? It's obvious from the design that of course they do but it tells me just how far is SpaceX has changed our approach to space flight when the whole idea throwing away perfectly good engines immediately strikes one as idiotic.

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    1. The SLS is a monument to building the most exotic and expensive hardware mankind knows how to make, stuff that's supposed to be the most reliable things made, and then throwing them out. Those engines are just under $150 million each - $600 million for the four of them on one flight - and they get used once.

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    2. Post-Moon Saturn rockets were being designed to drop the engine sections on recoverable platforms, much like with ULA's Vulcan (if the BE4s are ever delivered and work...) So throwing very very very expensive uprated Rocketdyne J2s, which is what SSME/RS25s are, away is a waste of money. Recover them, dammit. But, no, they'll just build more for SLS 5, 6, 7.... at $40-80 million a pop.

      This is NOT the future I was promised.

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  3. nASSa please just stop already. you're embarrassing us

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  4. Ah, dammit, NASA. Can't you ever prove me wrong? Feckless fewmet thieves...

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    1. Feckless fewmet thieves
      Outstanding...I'm stealing that
      Differ

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  5. NASA can't get their rocket off the ground , but they've already announce that the moon landing crew will be chosen to be the most PC , not necessarily the most competent .

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    1. Bingo! The whole mission statement of Artemis is, "land the first woman and the next man" on the moon. That's probably the only reason the program keeps getting funded.

      It's a rocket that's so expensive to launch that there won't even be ONE flight per year. By the time they get enough hardware in space to do things, it'll be 2035 and they won't be able to get parts to keep launching it.

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    2. D'oh!! Forgot the link to the published Artemis Schedule.

      Not enough coffee...

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    3. A woman of color !! She'll surely be the most qualified candidate to be found. See current VP, press secretary and most recent Supreme. What shining examples of ability and intellect they are.

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  6. The more I watch SLS stumble to get ONE rocket off the launch pad, the more I get the feeling that SpaceX will be there to greet the TWO astronauts that just might get to the surface of the Moon in 2025!

    Just sayin'

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    1. For political reasons, SpaceX will not be allowed to go to the Moon on their own. SpaceX is building the HLS for the Artemis program and that throws a monkey wrench into doing it on their own. They will not get the FAA, FCC and any other Federal Government agency's permission to launch an independent mission to the Moon.

      Most likely, the Artemis astronauts will be greeted by Tiakonauts (Chinese) and told to get off of the Chinese owned Moon (with guns pointed at the Astronauts).

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  7. SLS is a Congressional Jobs Program. Its also a social experiment in wokeness. I wonder how many NASA employees on the SLS program are in line to have their college loans waived, or were hired based on their race and sex, or sexual perversions and not their accomplishments as engineers and scientists.

    I can only suspect such biases exist because of the historical patterns of the Biden Regime.

    As for NASA Administrator Bill Nelson, his words and expressions speak for himself. A political appointee and little more.

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    1. An important point to remember is that Bill Nelson has pushing SLS from the start. Nelson was Florida Senator at the time SLS got started and was pushing it as a jobs program for shuttle workers with the apparent end of the shuttle program in sight.

      To borrow a quote from myself in October '21:

      There's an ironic story here. The SLS was first started as a make-work program in 2011 for companies from the Shuttle era, partly architected and pushed by Florida Senator (at the time) Bill Nelson. He proudly announced the SLS would be delivered on time and under budget.

      “This rocket is coming in at the cost of... not only what we estimated in the NASA Authorization act, but less,” Nelson said at the time. “The cost of the rocket over a five- to six-year period in the NASA authorization bill was to be no more than $11.5 billion. This costs $10 billion for the rocket.” Later, he went further, saying, "If we can't do a rocket for $11.5 billion, we ought to close up shop."

      As most of you know, a decade latter Bill Nelson is the NASA administrator, he's still pushing the SLS, the rocket still hasn't flown, its first flight has slipped yet again to 2022, and while they've gotten farther in the last year than at any time before now, the cost is over $30 billion so far. If not being able to "do a rocket for $11.5 billion" is a clue for being time to close up shop, not being able to do it for $30 billion should lead to the doors being nailed shut and the shop razed.

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