Artemis delay

[MBfreak]

In european papers the delay of the Artemis take off this week print that it was a faulty temperature sensor for the fuel, set at -420 F that showed a low value
of -375 F.
If fuel was at this value ( -375F) it would lead to major thrust problems.

Can somebody with real knowledge of this confirm taht it was a sensor malfunction

I have worked a lot with nuclear power station safety critical instrumentation systems.
We always used 4 paralell sensor channels and 3 must be identical, otherwise shutdown

Ola

 

[Stuart in MN]

A brief explanation of the cryogenic fuel temperatures posted yesterday on the NASA website: https://www.nasa.gov/exploration/sy...unch-system-rocket-engines-before-launch.html They do indeed chill the liquid hydrogen at -423F and the liquid oxygen at -297F when the tanks are filled. I don't know what happens to the temperatures of the two when they are mixed together at launch time.

I wasn't able to find a statement on the NASA website specifically about the sensor malfunction but have read the information on many news sites. They all said one sensor was reading differently than the others. They certainly have redundant sensors but I don't know how many, or how big the discrepancy has to be before there is a shutdown.

 

[Innovate1]

A brief explanation of the cryogenic fuel temperatures posted yesterday on the NASA website: https://www.nasa.gov/exploration/sy...unch-system-rocket-engines-before-launch.html They do indeed chill the liquid hydrogen at -423F and the liquid oxygen at -297F when the tanks are filled. I don't know what happens to the temperatures of the two when they are mixed together at launch time.

I wasn't able to find a statement on the NASA website specifically about the sensor malfunction but have read the information on many news sites. They all said one sensor was reading differently than the others. They certainly have redundant sensors but I don't know how many, or how big the discrepancy has to be before there is a shutdown.

They get really, really hot when mixed at launch. Seriously, they are kept separate except when burned.

As far as redundancy, I would think they would want them all functioning at launch. That way they can have some failures during flight and still be ok. If they can be bad at launch why not just have one less to start with?

 

[DAustin]

Does NASA buy from Lucas Electronics ?

 

[Plastikosmd]

Well Elon sent another up yesterday
Maybe the 14th time using that booster?
Stuck the landing in the barge also.


Funny how it hardly gets covered
34 more starlink sats

Good luck to the cobbled shuttle stuff and o-rings

 

[kaffine]

Looks like next launch attempt for Artemis is September 27th there is a 70 minute launch window starting at 11:37am EDT.

New Shepard by Blue Origin had an unmanned launch fail. The escape capsule worked though and separated from the 1st stage and landed.

https://spaceflightnow.com/2022/09/12/blue-origin-ns-23-launch/

 

[MBfreak]

Read Richard Feynmans analysis of the Challenger disaster.
The NASA top brass had distanced themselves from working staff. And hired idiots for reliability analysis.
They calculated that NASA could launch one rocket per day for 300 years, their calculations gave a statistic that showed 1 fault per 100.000 launches. They got EVERYTHING wrong, including high school statistic math.
The launch safety officers had figures between 30 and 300.

Ola