so, Artemis test flight AKA Should Launch Someday, 16-Nov-2022

[Zeta Reticulan]

1 minute ago, Sunshine said:

Yes, blowby of the O rings had occurred before Challenger, sad that it was swept under the carpet.

I believe the technicians knew it was too cold to launch and advised against it as they knew the rings could fracture. They were overruled for political reasons.  I'm sure Richard Feynman figured out what was wrong. I'm just too lazy to look it up. I'm tired after a pretty decent session with my 60 EDF lol.

[Stu]

Let’s keep the thread on track and not detail into debates about sports personalities please. Thank you

[CraigT82]

9 hours ago, Robindonne said:

Lol

Lol

[Stu]

6 hours ago, Sunshine said:

Yes, blowby of the O rings had occurred before Challenger, sad that it was swept under the carpet.

That was related to very cold weather though, so hopefully shouldn’t be any sort of issue currently.

[Stu]

12 hours ago, Zeta Reticulan said:

I'm wondering what the motive is to launch now. I would have thought all of the bugs would have been ironed out before a launch is even considered. Things don't go well for NASA when political decisions override technical decisions.  

Yes, I hope they’ve learnt enough from past failures to launch on technical and safety considerations alone these days.....

[Zeta Reticulan]

19 minutes ago, Stu said:

Yes, I hope they’ve learnt enough from past failures to launch on technical and safety considerations alone these days.....

I don't know. I don't think much has changed.

[Zeta Reticulan]

Sports personalities?

[maw lod qan]

My biggest issue is the never ending mentality of "massive" cost over budgets being acceptable!

It seems it doesn't matter if it's NASA, or defense related, it's just an accepted policy. 

I've always had to live ona budget.

This is what I'm giving you, if it's not enough, give it back. You need more, dig into your pockets, or sell some of your stocks.

[Mandy D]

7 hours ago, Zeta Reticulan said:

I believe the technicians knew it was too cold to launch and advised against it as they knew the rings could fracture. They were overruled for political reasons.  I'm sure Richard Feynman figured out what was wrong. I'm just too lazy to look it up. I'm tired after a pretty decent session with my 60 EDF lol.

IIRC, according to Feynman's own account, he was sat next to a general, whose name I forget, who clued Feynman in on the cold affecting the O-rings. Feynman somehow got his hands on a piece of the O-ring material and, during the hearing requested a glass of ice water and dropped the sample in it to demonstrate it's brittle state.

I could never figure why the general fed this information to Feynman rather than delivering it himself. It always looked suspicious to me. He may simply have felt that it looked better with the information coming from a scientist rather than the military!

[Zeta Reticulan]

11 minutes ago, Mandy D said:

IIRC, according to Feynman's own account, he was sat next to a general, whose name I forget, who clued Feynman in on the cold affecting the O-rings. Feynman somehow got his hands on a piece of the O-ring material and, during the hearing requested a glass of ice water and dropped the sample in it to demonstrate it's brittle state.

I could never figure why the general fed this information to Feynman rather than delivering it himself. It always looked suspicious to me. He may simply have felt that it looked better with the information coming from a scientist rather than the military!

Actually, I think I saw the movie. IIRC there were many aware of the problem but no one wanted to break a code of silence.

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." [After working on the Challenger investigation] ~ Richard Feynman (IMDb)

[Tomatobro]

There were a number of factors at play. When the shuttle engines start they bend the booster tube over as they are still held by the ground restraints. When the boosters light and the restraints are released the bending moment is released into the booster tubes and they flex back and forth during the early stages of lift off. The sealing rings, being stiffened by the cold allowed hot gasses to blow by the joint. The flex was around 0.3 htz as I recall and was confirmed by film which showed the puffs of smoke emerging at this frequency.

All this was known and small breaches of the joints were reported on earlier flights.  Mr Feynman at the time of the hearings was very ill with bowl cancer and had not long to live I guess there was a political element at play somewhere.

Like all accidents there are many factors which come together and remove just one and they become near misses instead of tragedies

I see now that where solid boosters are used they are always in line with the liquid fuel engines so the flex in the tubes is avoided

Edited August 30, 2022 by Tomatobro
more data

[DaveL59]

Sounds like there might be an update later today: (22:00 UK BST)

NASA to Provide Update on Artemis I Moon Mission Status - SpaceRef

and the blog from yesterday

Artemis (nasa.gov)

 

Edited August 30, 2022 by DaveL59

[DaveL59]

oops seems its 23:00 BST, countdown says 51 mins, assuming of course it doesn't go to hold at 40 😉 

[DaveL59]

Scrub was in part the chill-down and also a vent valve issue so the view seems to be to sort the valve issue, start the chill-down of engines earlier in the session and push launch out to saturday 3rd.

Also questioning the fidelity of the sensors monitoring the chill-down, esp re engine 3 that has a longer pipe run in the manifold than the other 3 engines

Edited August 30, 2022 by DaveL59

[DaveL59]

so listening to that session it makes me wonder, they only have single sensors per engine to verify this chill-down phase. Also tricky to try replace them on the pad so they're gonna work the data to determine if they're ok or not. Were Boing building these, sounds like a common theme here, no?

Lets hope they've at least a backup sensor in critical systems - this part is considered test rather than flight so corners cut I guess. Can't imagine tho that 4 extra sensors would cost more than aborting a launch.

Edited August 30, 2022 by DaveL59

[DaveL59]

according to the beeb, Should Launch Someday will be going up Saturday in a 2-hour windows from 19:17 BST

Artemis: Nasa will try to launch Moon rocket on Saturday - BBC News

Wonder if with the sky getting darker we'll see it pass over us at all?

[ScouseSpaceCadet]

22 minutes ago, DaveL59 said:

according to the beeb, Should Launch Someday will be going up Saturday in a 2-hour windows from 19:17 BST

Artemis: Nasa will try to launch Moon rocket on Saturday - BBC News

Wonder if with the sky getting darker we'll see it pass over us at all?

The rocket is launched eastward over the Atlantic and North Africa so it may be too far south for us?

[DaveL59]

2 minutes ago, ScouseSpaceCadet said:

The rocket is launched eastward over the Atlantic and North Africa so it may be too far south for us?

yeah probably, such is life huh

[jjohnson3803]

I almost cancelled a short camping trip over Monday b/c I didn't want to miss watching the launch.  Good thing I decided to go camping anyway and just watch a replay on YouTube.

Edited August 31, 2022 by jjohnson3803

[DaveL59]

didn't pick up the briefing session yesterday but seems it Should Launch Saturday

Artemis 1 moon mission is 'go' for Saturday launch, NASA says | Space

They've decided its a faulty sensor and sounds like they'll ignore it in the lead up to launch. Leak is apparently fixed and the crack in the foam is known risk.

Surprised they didn't drop someone down on a rope with some of that spray foam filler to fill the gap 😉 

Edited September 2, 2022 by DaveL59

[maw lod qan]

I'm scheduled to work, so will watch it livestream.

I still think it will be 50/50, but hope it goes. Boeing I'm my opinion is hanging on a thread.

If this gets put off for long, he who I shall not name will get his monstrosity in orbit first!

[DaveL59]

8 minutes ago, maw lod qan said:

I'm scheduled to work, so will watch it livestream.

I still think it will be 50/50, but hope it goes. Boeing I'm my opinion is hanging on a thread.

If this gets put off for long, he who I shall not name will get his monstrosity in orbit first!

yeah, wonder if they sorted all the glitches with the capsule/crew module from its run up to the ISS a while back or is this the second proving flight for it?

Am curious too if/how they've tested this abort/escape thing or is it a case of crossed fingers if/when they ever do need it.

[maw lod qan]

I just read a link that says they have 480 mission critical items to deal with during a launch. 

They have decided the #3 engine was getting the required hydrogen flow, so they are going to ignore the sensor which must be faulty.

They plan on starting the precooling earlier during tank fueling, then flush more through the system as the tanks pressurize!

[Ags]

22 minutes ago, maw lod qan said:

so they are going to ignore the sensor which must be faulty.

The boy who cried wolf. It might alert again on Saturday for a real issue.

[DaveL59]

As I'd mentioned before, can't believe on a ship that cost billions they cheaped out fitting non-redundant sensors, but then Boing have a track record here...