Washcloth delays SLS engine tests
The testing of an engine for the giant SLS rocket will be delayed because engineers have found the remains of a washcloth in the ducts of the test stand at Stennis Space Center.
The investigation found the fibers belong to a cotton shop rag from a weld shop that had been involved with working on the LOX duct ID surface during manufacture. The roughened surface (of the duct) was where the fibers were observed to be hanging up on.
The investigation team reported that, under microscope inspection, a piece of the run duct stock showed metallic particles loosely adhered to the ID surface and embedded in the ‘machining’ groves. Several were easily dislodged and identified as ID surface material. “A tape sample was pulled from the same stock (after an identical cleaning process) and produced a rather large quantity of particles. This is an unacceptable condition and it was agreed that the entire run duct will need to be replaced or reworked (~30-ft of pipe),” added the investigation notes.
Replacing the duct will cause a several month delay in the test program. Fortunately for NASA, they have some wiggle room (for the moment), since the entire SLS schedule has already slipped a year to 2018.
Nonetheless, do not be surprised if this is only the first of many further delays.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
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The testing of an engine for the giant SLS rocket will be delayed because engineers have found the remains of a washcloth in the ducts of the test stand at Stennis Space Center.
The investigation found the fibers belong to a cotton shop rag from a weld shop that had been involved with working on the LOX duct ID surface during manufacture. The roughened surface (of the duct) was where the fibers were observed to be hanging up on.
The investigation team reported that, under microscope inspection, a piece of the run duct stock showed metallic particles loosely adhered to the ID surface and embedded in the ‘machining’ groves. Several were easily dislodged and identified as ID surface material. “A tape sample was pulled from the same stock (after an identical cleaning process) and produced a rather large quantity of particles. This is an unacceptable condition and it was agreed that the entire run duct will need to be replaced or reworked (~30-ft of pipe),” added the investigation notes.
Replacing the duct will cause a several month delay in the test program. Fortunately for NASA, they have some wiggle room (for the moment), since the entire SLS schedule has already slipped a year to 2018.
Nonetheless, do not be surprised if this is only the first of many further delays.
The support of my readers through the years has given me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Four years ago, just before the 2020 election I wrote that Joe Biden's mental health was suspect. Only in this year has the propaganda mainstream media decided to recognize that basic fact.
Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Even today NASA and Congress refuse to recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
Please consider supporting my work here at Behind the Black.
You can support me either by giving a one-time contribution or a regular subscription. There are five ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation:
5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above. And if you buy the books through the ebookit links, I get a larger cut and I get it sooner.
A duct that will handle thousands to millions of gallons of LOX is being replaced since it has some cotton fibers on it. Odds are really good on first test, the LOX will combust the fibers and they last micro seconds. (I know, there are real concerns, early ignition, whatever, but still seems strange).
Contrast a Merlin 1 where one of the acceptance tests is to drop a standard 5/8″ nut through the fuel flow, for the pump to handle and not RUD.
Designing for reliability is tough.
I once fully assembled a Chevy 350 LTI engine and wondered why it was bogged down upon the first test run. I assembled the top end and left a towel stuffed in the new manifold. It happens :)
Stuff does happen, but if you had 40 people looking at and helping you with that engine and a 4 million dollar budget you would think someone would find it long before you started the engine.
but but .. my dog ate my homework… can you give a few more days?
Bob, on Tuesday’s john Batchelor Show, I heard you wondering about why NASA was bothering to test the Shuttle engines at Stennis, since they’re a totally proven and known system. In a July issue of Aviation week, there was a mention of tests of that engine with a new controller that had originally been developed for the J-2X engine. The obsolete electronics supply chain for the shuttle is definitely an issue that needs to be addressed in any shuttle-derived hardware production. Which of course only adds to the ever-expanding costs of SLS…
Matt,
Thank you for the information. It explains the tests, though it also provides further proof that SLS is a stupid waste of money.