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.