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#100
by
haywoodfloyd
on 01 Jun, 2024 20:44
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Tory said they have occasionally had similar launch sequencer issues with previous Atlas launches. Not common, but not unheard off (just like with the valve issue back in May).
When was this system designed, and how old are these specific cards? Atlas has been launching from SLC-41 since 2002. The fact that this was a triple-redundant system that was apparently implemented on three cards instead of one card makes it sound like a venerable design.
It is a venerble design by the fact that it is on 3 separate cards - much more desirable than so-called triple redundancy on one card, which is not really triple redundancy at all.
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#101
by
DanClemmensen
on 01 Jun, 2024 21:32
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Tory said they have occasionally had similar launch sequencer issues with previous Atlas launches. Not common, but not unheard off (just like with the valve issue back in May).
When was this system designed, and how old are these specific cards? Atlas has been launching from SLC-41 since 2002. The fact that this was a triple-redundant system that was apparently implemented on three cards instead of one card makes it sound like a venerable design.
It is a venerble design by the fact that it is on 3 separate cards - much more desirable than so-called triple redundancy on one card, which is not really triple redundancy at all.
I have architected successful redundant systems. You need three (or more) cards if you need to support hot swap. In the GLS case, for reasons that are unclear they need all three cards to be functional: the scrub occurred because one card failed, and hot swap is not used. If all three elements must function, then (other things being equal) one card is more reliable than three cards, simply because traces on a PC card are more reliable than connectors. In earlier decades, the circuitry was more likely to be so large that it needed to be on multiple cards anyway, but depending on the function it is now often feasible to use a single card.
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#102
by
24Launch
on 01 Jun, 2024 21:45
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This one had me going what?
Less than 20 minutes before liftoff, spacecraft controllers noted a problem with fans that circulate air in the pressure suits Wilmore and Williams were wearing. The fans were working again a few minutes later. Mark Nappi, Boeing vice president and commercial crew program manager, said at the briefing that a voltage change as the spacecraft switched to internal power caused the fans to turn off, and spacecraft controllers turned them back on.However minor, it begs the question, was this a one-time glitch or was this another step skipped in all the prior rehersal testing to date and we finally got "this far" and oops?
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#103
by
SoftwareDude
on 01 Jun, 2024 22:04
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Does anyone know what kind of computer failed? Like IBM 4 PI, maybe?
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#104
by
Yellowstone10
on 01 Jun, 2024 23:19
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Was just watching back through the launch stream and noticed a couple of shots of Playalinda from the NASA security helicopter. I wonder if any other NSFers are in the crowd down there?
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#105
by
meekGee
on 01 Jun, 2024 23:39
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This one had me going what?
Less than 20 minutes before liftoff, spacecraft controllers noted a problem with fans that circulate air in the pressure suits Wilmore and Williams were wearing. The fans were working again a few minutes later. Mark Nappi, Boeing vice president and commercial crew program manager, said at the briefing that a voltage change as the spacecraft switched to internal power caused the fans to turn off, and spacecraft controllers turned them back on.
However minor, it begs the question, was this a one-time glitch or was this another step skipped in all the prior rehearsal testing to date and we finally got "this far" and oops?
Somewhere between the parachutes, the old valves, the new valves, valve data links, fans, helium leaks - they each have a long winded explanation, but they do add up, don't they.
And it's two separate systems, I know. One is brand spanking new, the other one supposedly an old venerable launch vehicle - and still here we are. It does make you wonder.
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#106
by
cplchanb
on 02 Jun, 2024 01:20
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Honestly this is getting laughable and almost downright amateurish how many fundamental issues are coming in. First it was software, then sticky valves, then more valves, then a helium leak, now another software issue with a supposedly very mature launcher system. It really seems like someone on high really doesn't want starkiner to launch properly...
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#107
by
LouScheffer
on 02 Jun, 2024 01:53
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Tory said they have occasionally had similar launch sequencer issues with previous Atlas launches. Not common, but not unheard off (just like with the valve issue back in May).
I find this attitude concerning, verging on unprofessional. If you have a known problem that bites you a few percent of the time, then something is marginal in your procedures or equipment. A small change in conditions might then cause more frequent failures, up to and including failing every time. If this happens you are forced to fix it, on your customer's clock. And even if the failures stay infrequent, but are not eliminated, it will make a reliable and sustained cadence almost impossible. It seems to me that any failure that happens the same way more than once should be eliminated, not worked around. To do otherwise is riding your luck and asking for trouble - not a good look for a company that wants to be known for solid engineering.
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#108
by
zubenelgenubi
on 02 Jun, 2024 01:55
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Moderator:
The "you are destroying the forum" comments have been deleted. Ad hominem attacks are not allowed on this forum.
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#109
by
Tomness
on 02 Jun, 2024 02:31
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I feel for Butch and Suni. They are on a strict liquid diet until they make it to the ISS. But i am sure Starliner will be worth it and be more roomier then Soyuez. But no toilet like Dragon.
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#110
by
meekGee
on 02 Jun, 2024 03:00
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Tory said they have occasionally had similar launch sequencer issues with previous Atlas launches. Not common, but not unheard off (just like with the valve issue back in May).
I find this attitude concerning, verging on unprofessional. If you have a known problem that bites you a few percent of the time, then something is marginal in your procedures or equipment. A small change in conditions might then cause more frequent failures, up to and including failing every time. If this happens you are forced to fix it, on your customer's clock. And even if the failures stay infrequent, but are not eliminated, it will make a reliable and sustained cadence almost impossible. It seems to me that any failure that happens the same way more than once should be eliminated, not worked around. To do otherwise is riding your luck and asking for trouble - not a good look for a company that wants to be known for solid engineering.
We had the same discussion over a number of faults, like the valves of the previous scrub. That's on the ULA side.
Then similar bad habits on the Boeing side with Starliner.
It's endemic to the industry, looks like.
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#111
by
John_Marshall
on 02 Jun, 2024 03:09
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I feel for Butch and Suni. They are on a strict liquid diet until they make it to the ISS. But i am sure Starliner will be worth it and be more roomier then Soyuez. But no toilet like Dragon.
A liquid diet and no toilet?! YIKES. Is it always going to be like this on Starliner, or is this a one-off?
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#112
by
sdsds
on 02 Jun, 2024 03:16
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This one had me going what?
Less than 20 minutes before liftoff, spacecraft controllers noted a problem with fans that circulate air in the pressure suits Wilmore and Williams were wearing. The fans were working again a few minutes later. Mark Nappi, Boeing vice president and commercial crew program manager, said at the briefing that a voltage change as the spacecraft switched to internal power caused the fans to turn off, and spacecraft controllers turned them back on.
Quick take: this launch attempt is a "no news is good news" event. They didn't go to space today, and that's an acceptable outcome.
I too was struck more by the suit fan issue than the launch control system issue. Happily it was easy to resolve it quickly. That said, transitions to internal power are common in space launch. Does the industry have 'standard' test cases for that?
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#113
by
joek
on 02 Jun, 2024 03:22
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I feel for Butch and Suni. They are on a strict liquid diet until they make it to the ISS. But i am sure Starliner will be worth it and be more roomier then Soyuez. But no toilet like Dragon.
Like similar missions, crew is likely on a "low residual" diet, so they can make do without spacecraft toilet.
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#114
by
deltaV
on 02 Jun, 2024 03:35
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I feel for Butch and Suni. They are on a strict liquid diet until they make it to the ISS. But i am sure Starliner will be worth it and be more roomier then Soyuez. But no toilet like Dragon.
This diet presumably includes very little fiber and fiber is important for health. I wonder if NASA considered the impact of this diet on astronaut life expectancy when evaluating Starliner's safety. This diet is probably not the majority of the overall dangers of Starliner as quantified by expected disability-adjusted life years lost but it may be significant enough to matter. I'm not sure anyone has any good data of how dangerous an occasional liquid diet is.
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#115
by
meekGee
on 02 Jun, 2024 04:40
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I feel for Butch and Suni. They are on a strict liquid diet until they make it to the ISS. But i am sure Starliner will be worth it and be more roomier then Soyuez. But no toilet like Dragon.
This diet presumably includes very little fiber and fiber is important for health. I wonder if NASA considered the impact of this diet on astronaut life expectancy when evaluating Starliner's safety. This diet is probably not the majority of the overall dangers of Starliner as quantified by expected disability-adjusted life years lost but it may be significant enough to matter. I'm not sure anyone has any good data of how dangerous an occasional liquid diet is.
It's like climate vs. weather.
Fiber is important as a rule, as are other things, but you can go on any non-poisonous diet for a week or two and nothing bad will happen.
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#116
by
Jimmy10
on 02 Jun, 2024 06:50
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Can someone please remind me (I can't find the post that originally dealt with this question, sorry), the Starliner stack was rolled to the pad on 26/04/24 (date the correct way round) if IIRC. I'm sure I saw a post that said that there are some consumables (solid fuels?) which are only certified for a defined period post roll out, and these limits would be met on 07/06/24? So if we get a couple of (hopefully no more serious than) weather delays, does the stack need to return to the barn for a refurb anyway around that time?
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#117
by
deltaV
on 02 Jun, 2024 07:04
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It's like climate vs. weather.
Fiber is important as a rule, as are other things, but you can go on any non-poisonous diet for a week or two and nothing bad will happen.
If the effect is linear then being on a bad diet for a couple weeks would hurt life expectancy by something like a day. Do you have scientific evidence that a linear model isn't correct here?
Edit: if life expectancy is 35 years, increasing probability of loss of crew from 1 in 270 to 1 in 264.4 costs one day of life expectancy. So an extra day of life expectancy is not huge but could make the difference between barely meeting the LOC requirement and barely not.
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#118
by
Jim
on 02 Jun, 2024 12:10
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This one had me going what?
Less than 20 minutes before liftoff, spacecraft controllers noted a problem with fans that circulate air in the pressure suits Wilmore and Williams were wearing. The fans were working again a few minutes later. Mark Nappi, Boeing vice president and commercial crew program manager, said at the briefing that a voltage change as the spacecraft switched to internal power caused the fans to turn off, and spacecraft controllers turned them back on.
However minor, it begs the question, was this a one-time glitch or was this another step skipped in all the prior rehersal testing to date and we finally got "this far" and oops?
Glitch that would likely result in change to a limit setting that was too tight. Ground power is supplied by power supplies that can hold steady voltage levels regardless of amperage loads; unlike batteries, whose voltage output will vary as loads increase.
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#119
by
Jim
on 02 Jun, 2024 12:19
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Honestly this is getting laughable and almost downright amateurish how many fundamental issues are coming in. First it was software, then sticky valves, then more valves, then a helium leak, now another software issue with a supposedly very mature launcher system. It really seems like someone on high really doesn't want starkiner to launch properly...
It wasn't a software issue.
